1 //===-- RuntimeDyldELF.cpp - Run-time dynamic linker for MC-JIT -*- 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 // Implementation of ELF support for the MC-JIT runtime dynamic linker.
11 //
12 //===----------------------------------------------------------------------===//
13 
14 #include "RuntimeDyldELF.h"
15 #include "JITRegistrar.h"
16 #include "ObjectImageCommon.h"
17 #include "llvm/ADT/IntervalMap.h"
18 #include "llvm/ADT/STLExtras.h"
19 #include "llvm/ADT/StringRef.h"
20 #include "llvm/ADT/Triple.h"
21 #include "llvm/ExecutionEngine/ObjectBuffer.h"
22 #include "llvm/ExecutionEngine/ObjectImage.h"
23 #include "llvm/Object/ELFObjectFile.h"
24 #include "llvm/Object/ObjectFile.h"
25 #include "llvm/Support/ELF.h"
26 #include "llvm/Support/MemoryBuffer.h"
27 
28 using namespace llvm;
29 using namespace llvm::object;
30 
31 #define DEBUG_TYPE "dyld"
32 
33 namespace {
34 
35 static inline std::error_code check(std::error_code Err) {
36   if (Err) {
37     report_fatal_error(Err.message());
38   }
39   return Err;
40 }
41 
42 template <class ELFT> class DyldELFObject : public ELFObjectFile<ELFT> {
43   LLVM_ELF_IMPORT_TYPES_ELFT(ELFT)
44 
45   typedef Elf_Shdr_Impl<ELFT> Elf_Shdr;
46   typedef Elf_Sym_Impl<ELFT> Elf_Sym;
47   typedef Elf_Rel_Impl<ELFT, false> Elf_Rel;
48   typedef Elf_Rel_Impl<ELFT, true> Elf_Rela;
49 
50   typedef Elf_Ehdr_Impl<ELFT> Elf_Ehdr;
51 
52   typedef typename ELFDataTypeTypedefHelper<ELFT>::value_type addr_type;
53 
54   std::unique_ptr<ObjectFile> UnderlyingFile;
55 
56 public:
57   DyldELFObject(std::unique_ptr<ObjectFile> UnderlyingFile,
58                 std::unique_ptr<MemoryBuffer> Wrapper, std::error_code &ec);
59 
60   DyldELFObject(std::unique_ptr<MemoryBuffer> Wrapper, std::error_code &ec);
61 
62   void updateSectionAddress(const SectionRef &Sec, uint64_t Addr);
63   void updateSymbolAddress(const SymbolRef &Sym, uint64_t Addr);
64 
65   // Methods for type inquiry through isa, cast and dyn_cast
66   static inline bool classof(const Binary *v) {
67     return (isa<ELFObjectFile<ELFT>>(v) &&
68             classof(cast<ELFObjectFile<ELFT>>(v)));
69   }
70   static inline bool classof(const ELFObjectFile<ELFT> *v) {
71     return v->isDyldType();
72   }
73 };
74 
75 template <class ELFT> class ELFObjectImage : public ObjectImageCommon {
76   bool Registered;
77 
78 public:
79   ELFObjectImage(ObjectBuffer *Input, std::unique_ptr<DyldELFObject<ELFT>> Obj)
80       : ObjectImageCommon(Input, std::move(Obj)), Registered(false) {}
81 
82   virtual ~ELFObjectImage() {
83     if (Registered)
84       deregisterWithDebugger();
85   }
86 
87   // Subclasses can override these methods to update the image with loaded
88   // addresses for sections and common symbols
89   void updateSectionAddress(const SectionRef &Sec, uint64_t Addr) override {
90     static_cast<DyldELFObject<ELFT>*>(getObjectFile())
91         ->updateSectionAddress(Sec, Addr);
92   }
93 
94   void updateSymbolAddress(const SymbolRef &Sym, uint64_t Addr) override {
95     static_cast<DyldELFObject<ELFT>*>(getObjectFile())
96         ->updateSymbolAddress(Sym, Addr);
97   }
98 
99   void registerWithDebugger() override {
100     JITRegistrar::getGDBRegistrar().registerObject(*Buffer);
101     Registered = true;
102   }
103   void deregisterWithDebugger() override {
104     JITRegistrar::getGDBRegistrar().deregisterObject(*Buffer);
105   }
106 };
107 
108 // The MemoryBuffer passed into this constructor is just a wrapper around the
109 // actual memory.  Ultimately, the Binary parent class will take ownership of
110 // this MemoryBuffer object but not the underlying memory.
111 template <class ELFT>
112 DyldELFObject<ELFT>::DyldELFObject(std::unique_ptr<MemoryBuffer> Wrapper,
113                                    std::error_code &EC)
114     : ELFObjectFile<ELFT>(std::move(Wrapper), EC) {
115   this->isDyldELFObject = true;
116 }
117 
118 template <class ELFT>
119 DyldELFObject<ELFT>::DyldELFObject(std::unique_ptr<ObjectFile> UnderlyingFile,
120                                    std::unique_ptr<MemoryBuffer> Wrapper,
121                                    std::error_code &EC)
122     : ELFObjectFile<ELFT>(std::move(Wrapper), EC),
123       UnderlyingFile(std::move(UnderlyingFile)) {
124   this->isDyldELFObject = true;
125 }
126 
127 template <class ELFT>
128 void DyldELFObject<ELFT>::updateSectionAddress(const SectionRef &Sec,
129                                                uint64_t Addr) {
130   DataRefImpl ShdrRef = Sec.getRawDataRefImpl();
131   Elf_Shdr *shdr =
132       const_cast<Elf_Shdr *>(reinterpret_cast<const Elf_Shdr *>(ShdrRef.p));
133 
134   // This assumes the address passed in matches the target address bitness
135   // The template-based type cast handles everything else.
136   shdr->sh_addr = static_cast<addr_type>(Addr);
137 }
138 
139 template <class ELFT>
140 void DyldELFObject<ELFT>::updateSymbolAddress(const SymbolRef &SymRef,
141                                               uint64_t Addr) {
142 
143   Elf_Sym *sym = const_cast<Elf_Sym *>(
144       ELFObjectFile<ELFT>::getSymbol(SymRef.getRawDataRefImpl()));
145 
146   // This assumes the address passed in matches the target address bitness
147   // The template-based type cast handles everything else.
148   sym->st_value = static_cast<addr_type>(Addr);
149 }
150 
151 } // namespace
152 
153 namespace llvm {
154 
155 void RuntimeDyldELF::registerEHFrames() {
156   if (!MemMgr)
157     return;
158   for (int i = 0, e = UnregisteredEHFrameSections.size(); i != e; ++i) {
159     SID EHFrameSID = UnregisteredEHFrameSections[i];
160     uint8_t *EHFrameAddr = Sections[EHFrameSID].Address;
161     uint64_t EHFrameLoadAddr = Sections[EHFrameSID].LoadAddress;
162     size_t EHFrameSize = Sections[EHFrameSID].Size;
163     MemMgr->registerEHFrames(EHFrameAddr, EHFrameLoadAddr, EHFrameSize);
164     RegisteredEHFrameSections.push_back(EHFrameSID);
165   }
166   UnregisteredEHFrameSections.clear();
167 }
168 
169 void RuntimeDyldELF::deregisterEHFrames() {
170   if (!MemMgr)
171     return;
172   for (int i = 0, e = RegisteredEHFrameSections.size(); i != e; ++i) {
173     SID EHFrameSID = RegisteredEHFrameSections[i];
174     uint8_t *EHFrameAddr = Sections[EHFrameSID].Address;
175     uint64_t EHFrameLoadAddr = Sections[EHFrameSID].LoadAddress;
176     size_t EHFrameSize = Sections[EHFrameSID].Size;
177     MemMgr->deregisterEHFrames(EHFrameAddr, EHFrameLoadAddr, EHFrameSize);
178   }
179   RegisteredEHFrameSections.clear();
180 }
181 
182 ObjectImage *
183 RuntimeDyldELF::createObjectImageFromFile(std::unique_ptr<object::ObjectFile> ObjFile) {
184   if (!ObjFile)
185     return nullptr;
186 
187   std::error_code ec;
188   std::unique_ptr<MemoryBuffer> Buffer(
189       MemoryBuffer::getMemBuffer(ObjFile->getData(), "", false));
190 
191   if (ObjFile->getBytesInAddress() == 4 && ObjFile->isLittleEndian()) {
192     auto Obj =
193         llvm::make_unique<DyldELFObject<ELFType<support::little, 2, false>>>(
194             std::move(ObjFile), std::move(Buffer), ec);
195     return new ELFObjectImage<ELFType<support::little, 2, false>>(
196         nullptr, std::move(Obj));
197   } else if (ObjFile->getBytesInAddress() == 4 && !ObjFile->isLittleEndian()) {
198     auto Obj =
199         llvm::make_unique<DyldELFObject<ELFType<support::big, 2, false>>>(
200             std::move(ObjFile), std::move(Buffer), ec);
201     return new ELFObjectImage<ELFType<support::big, 2, false>>(nullptr, std::move(Obj));
202   } else if (ObjFile->getBytesInAddress() == 8 && !ObjFile->isLittleEndian()) {
203     auto Obj = llvm::make_unique<DyldELFObject<ELFType<support::big, 2, true>>>(
204         std::move(ObjFile), std::move(Buffer), ec);
205     return new ELFObjectImage<ELFType<support::big, 2, true>>(nullptr,
206                                                               std::move(Obj));
207   } else if (ObjFile->getBytesInAddress() == 8 && ObjFile->isLittleEndian()) {
208     auto Obj =
209         llvm::make_unique<DyldELFObject<ELFType<support::little, 2, true>>>(
210             std::move(ObjFile), std::move(Buffer), ec);
211     return new ELFObjectImage<ELFType<support::little, 2, true>>(
212         nullptr, std::move(Obj));
213   } else
214     llvm_unreachable("Unexpected ELF format");
215 }
216 
217 ObjectImage *RuntimeDyldELF::createObjectImage(ObjectBuffer *Buffer) {
218   if (Buffer->getBufferSize() < ELF::EI_NIDENT)
219     llvm_unreachable("Unexpected ELF object size");
220   std::pair<unsigned char, unsigned char> Ident =
221       std::make_pair((uint8_t)Buffer->getBufferStart()[ELF::EI_CLASS],
222                      (uint8_t)Buffer->getBufferStart()[ELF::EI_DATA]);
223   std::error_code ec;
224 
225   std::unique_ptr<MemoryBuffer> Buf(Buffer->getMemBuffer());
226 
227   if (Ident.first == ELF::ELFCLASS32 && Ident.second == ELF::ELFDATA2LSB) {
228     auto Obj =
229         llvm::make_unique<DyldELFObject<ELFType<support::little, 4, false>>>(
230             std::move(Buf), ec);
231     return new ELFObjectImage<ELFType<support::little, 4, false>>(
232         Buffer, std::move(Obj));
233   } else if (Ident.first == ELF::ELFCLASS32 &&
234              Ident.second == ELF::ELFDATA2MSB) {
235     auto Obj =
236         llvm::make_unique<DyldELFObject<ELFType<support::big, 4, false>>>(
237             std::move(Buf), ec);
238     return new ELFObjectImage<ELFType<support::big, 4, false>>(Buffer,
239                                                                std::move(Obj));
240   } else if (Ident.first == ELF::ELFCLASS64 &&
241              Ident.second == ELF::ELFDATA2MSB) {
242     auto Obj = llvm::make_unique<DyldELFObject<ELFType<support::big, 8, true>>>(
243         std::move(Buf), ec);
244     return new ELFObjectImage<ELFType<support::big, 8, true>>(Buffer, std::move(Obj));
245   } else if (Ident.first == ELF::ELFCLASS64 &&
246              Ident.second == ELF::ELFDATA2LSB) {
247     auto Obj =
248         llvm::make_unique<DyldELFObject<ELFType<support::little, 8, true>>>(
249             std::move(Buf), ec);
250     return new ELFObjectImage<ELFType<support::little, 8, true>>(Buffer, std::move(Obj));
251   } else
252     llvm_unreachable("Unexpected ELF format");
253 }
254 
255 RuntimeDyldELF::~RuntimeDyldELF() {}
256 
257 void RuntimeDyldELF::resolveX86_64Relocation(const SectionEntry &Section,
258                                              uint64_t Offset, uint64_t Value,
259                                              uint32_t Type, int64_t Addend,
260                                              uint64_t SymOffset) {
261   switch (Type) {
262   default:
263     llvm_unreachable("Relocation type not implemented yet!");
264     break;
265   case ELF::R_X86_64_64: {
266     uint64_t *Target = reinterpret_cast<uint64_t *>(Section.Address + Offset);
267     *Target = Value + Addend;
268     DEBUG(dbgs() << "Writing " << format("%p", (Value + Addend)) << " at "
269                  << format("%p\n", Target));
270     break;
271   }
272   case ELF::R_X86_64_32:
273   case ELF::R_X86_64_32S: {
274     Value += Addend;
275     assert((Type == ELF::R_X86_64_32 && (Value <= UINT32_MAX)) ||
276            (Type == ELF::R_X86_64_32S &&
277             ((int64_t)Value <= INT32_MAX && (int64_t)Value >= INT32_MIN)));
278     uint32_t TruncatedAddr = (Value & 0xFFFFFFFF);
279     uint32_t *Target = reinterpret_cast<uint32_t *>(Section.Address + Offset);
280     *Target = TruncatedAddr;
281     DEBUG(dbgs() << "Writing " << format("%p", TruncatedAddr) << " at "
282                  << format("%p\n", Target));
283     break;
284   }
285   case ELF::R_X86_64_GOTPCREL: {
286     // findGOTEntry returns the 'G + GOT' part of the relocation calculation
287     // based on the load/target address of the GOT (not the current/local addr).
288     uint64_t GOTAddr = findGOTEntry(Value, SymOffset);
289     uint32_t *Target = reinterpret_cast<uint32_t *>(Section.Address + Offset);
290     uint64_t FinalAddress = Section.LoadAddress + Offset;
291     // The processRelocationRef method combines the symbol offset and the addend
292     // and in most cases that's what we want.  For this relocation type, we need
293     // the raw addend, so we subtract the symbol offset to get it.
294     int64_t RealOffset = GOTAddr + Addend - SymOffset - FinalAddress;
295     assert(RealOffset <= INT32_MAX && RealOffset >= INT32_MIN);
296     int32_t TruncOffset = (RealOffset & 0xFFFFFFFF);
297     *Target = TruncOffset;
298     break;
299   }
300   case ELF::R_X86_64_PC32: {
301     // Get the placeholder value from the generated object since
302     // a previous relocation attempt may have overwritten the loaded version
303     uint32_t *Placeholder =
304         reinterpret_cast<uint32_t *>(Section.ObjAddress + Offset);
305     uint32_t *Target = reinterpret_cast<uint32_t *>(Section.Address + Offset);
306     uint64_t FinalAddress = Section.LoadAddress + Offset;
307     int64_t RealOffset = *Placeholder + Value + Addend - FinalAddress;
308     assert(RealOffset <= INT32_MAX && RealOffset >= INT32_MIN);
309     int32_t TruncOffset = (RealOffset & 0xFFFFFFFF);
310     *Target = TruncOffset;
311     break;
312   }
313   case ELF::R_X86_64_PC64: {
314     // Get the placeholder value from the generated object since
315     // a previous relocation attempt may have overwritten the loaded version
316     uint64_t *Placeholder =
317         reinterpret_cast<uint64_t *>(Section.ObjAddress + Offset);
318     uint64_t *Target = reinterpret_cast<uint64_t *>(Section.Address + Offset);
319     uint64_t FinalAddress = Section.LoadAddress + Offset;
320     *Target = *Placeholder + Value + Addend - FinalAddress;
321     break;
322   }
323   }
324 }
325 
326 void RuntimeDyldELF::resolveX86Relocation(const SectionEntry &Section,
327                                           uint64_t Offset, uint32_t Value,
328                                           uint32_t Type, int32_t Addend) {
329   switch (Type) {
330   case ELF::R_386_32: {
331     // Get the placeholder value from the generated object since
332     // a previous relocation attempt may have overwritten the loaded version
333     uint32_t *Placeholder =
334         reinterpret_cast<uint32_t *>(Section.ObjAddress + Offset);
335     uint32_t *Target = reinterpret_cast<uint32_t *>(Section.Address + Offset);
336     *Target = *Placeholder + Value + Addend;
337     break;
338   }
339   case ELF::R_386_PC32: {
340     // Get the placeholder value from the generated object since
341     // a previous relocation attempt may have overwritten the loaded version
342     uint32_t *Placeholder =
343         reinterpret_cast<uint32_t *>(Section.ObjAddress + Offset);
344     uint32_t *Target = reinterpret_cast<uint32_t *>(Section.Address + Offset);
345     uint32_t FinalAddress = ((Section.LoadAddress + Offset) & 0xFFFFFFFF);
346     uint32_t RealOffset = *Placeholder + Value + Addend - FinalAddress;
347     *Target = RealOffset;
348     break;
349   }
350   default:
351     // There are other relocation types, but it appears these are the
352     // only ones currently used by the LLVM ELF object writer
353     llvm_unreachable("Relocation type not implemented yet!");
354     break;
355   }
356 }
357 
358 void RuntimeDyldELF::resolveAArch64Relocation(const SectionEntry &Section,
359                                               uint64_t Offset, uint64_t Value,
360                                               uint32_t Type, int64_t Addend) {
361   uint32_t *TargetPtr = reinterpret_cast<uint32_t *>(Section.Address + Offset);
362   uint64_t FinalAddress = Section.LoadAddress + Offset;
363 
364   DEBUG(dbgs() << "resolveAArch64Relocation, LocalAddress: 0x"
365                << format("%llx", Section.Address + Offset)
366                << " FinalAddress: 0x" << format("%llx", FinalAddress)
367                << " Value: 0x" << format("%llx", Value) << " Type: 0x"
368                << format("%x", Type) << " Addend: 0x" << format("%llx", Addend)
369                << "\n");
370 
371   switch (Type) {
372   default:
373     llvm_unreachable("Relocation type not implemented yet!");
374     break;
375   case ELF::R_AARCH64_ABS64: {
376     uint64_t *TargetPtr =
377         reinterpret_cast<uint64_t *>(Section.Address + Offset);
378     *TargetPtr = Value + Addend;
379     break;
380   }
381   case ELF::R_AARCH64_PREL32: {
382     uint64_t Result = Value + Addend - FinalAddress;
383     assert(static_cast<int64_t>(Result) >= INT32_MIN &&
384            static_cast<int64_t>(Result) <= UINT32_MAX);
385     *TargetPtr = static_cast<uint32_t>(Result & 0xffffffffU);
386     break;
387   }
388   case ELF::R_AARCH64_CALL26: // fallthrough
389   case ELF::R_AARCH64_JUMP26: {
390     // Operation: S+A-P. Set Call or B immediate value to bits fff_fffc of the
391     // calculation.
392     uint64_t BranchImm = Value + Addend - FinalAddress;
393 
394     // "Check that -2^27 <= result < 2^27".
395     assert(-(1LL << 27) <= static_cast<int64_t>(BranchImm) &&
396            static_cast<int64_t>(BranchImm) < (1LL << 27));
397 
398     // AArch64 code is emitted with .rela relocations. The data already in any
399     // bits affected by the relocation on entry is garbage.
400     *TargetPtr &= 0xfc000000U;
401     // Immediate goes in bits 25:0 of B and BL.
402     *TargetPtr |= static_cast<uint32_t>(BranchImm & 0xffffffcU) >> 2;
403     break;
404   }
405   case ELF::R_AARCH64_MOVW_UABS_G3: {
406     uint64_t Result = Value + Addend;
407 
408     // AArch64 code is emitted with .rela relocations. The data already in any
409     // bits affected by the relocation on entry is garbage.
410     *TargetPtr &= 0xffe0001fU;
411     // Immediate goes in bits 20:5 of MOVZ/MOVK instruction
412     *TargetPtr |= Result >> (48 - 5);
413     // Shift must be "lsl #48", in bits 22:21
414     assert((*TargetPtr >> 21 & 0x3) == 3 && "invalid shift for relocation");
415     break;
416   }
417   case ELF::R_AARCH64_MOVW_UABS_G2_NC: {
418     uint64_t Result = Value + Addend;
419 
420     // AArch64 code is emitted with .rela relocations. The data already in any
421     // bits affected by the relocation on entry is garbage.
422     *TargetPtr &= 0xffe0001fU;
423     // Immediate goes in bits 20:5 of MOVZ/MOVK instruction
424     *TargetPtr |= ((Result & 0xffff00000000ULL) >> (32 - 5));
425     // Shift must be "lsl #32", in bits 22:21
426     assert((*TargetPtr >> 21 & 0x3) == 2 && "invalid shift for relocation");
427     break;
428   }
429   case ELF::R_AARCH64_MOVW_UABS_G1_NC: {
430     uint64_t Result = Value + Addend;
431 
432     // AArch64 code is emitted with .rela relocations. The data already in any
433     // bits affected by the relocation on entry is garbage.
434     *TargetPtr &= 0xffe0001fU;
435     // Immediate goes in bits 20:5 of MOVZ/MOVK instruction
436     *TargetPtr |= ((Result & 0xffff0000U) >> (16 - 5));
437     // Shift must be "lsl #16", in bits 22:2
438     assert((*TargetPtr >> 21 & 0x3) == 1 && "invalid shift for relocation");
439     break;
440   }
441   case ELF::R_AARCH64_MOVW_UABS_G0_NC: {
442     uint64_t Result = Value + Addend;
443 
444     // AArch64 code is emitted with .rela relocations. The data already in any
445     // bits affected by the relocation on entry is garbage.
446     *TargetPtr &= 0xffe0001fU;
447     // Immediate goes in bits 20:5 of MOVZ/MOVK instruction
448     *TargetPtr |= ((Result & 0xffffU) << 5);
449     // Shift must be "lsl #0", in bits 22:21.
450     assert((*TargetPtr >> 21 & 0x3) == 0 && "invalid shift for relocation");
451     break;
452   }
453   case ELF::R_AARCH64_ADR_PREL_PG_HI21: {
454     // Operation: Page(S+A) - Page(P)
455     uint64_t Result =
456         ((Value + Addend) & ~0xfffULL) - (FinalAddress & ~0xfffULL);
457 
458     // Check that -2^32 <= X < 2^32
459     assert(static_cast<int64_t>(Result) >= (-1LL << 32) &&
460            static_cast<int64_t>(Result) < (1LL << 32) &&
461            "overflow check failed for relocation");
462 
463     // AArch64 code is emitted with .rela relocations. The data already in any
464     // bits affected by the relocation on entry is garbage.
465     *TargetPtr &= 0x9f00001fU;
466     // Immediate goes in bits 30:29 + 5:23 of ADRP instruction, taken
467     // from bits 32:12 of X.
468     *TargetPtr |= ((Result & 0x3000U) << (29 - 12));
469     *TargetPtr |= ((Result & 0x1ffffc000ULL) >> (14 - 5));
470     break;
471   }
472   case ELF::R_AARCH64_LDST32_ABS_LO12_NC: {
473     // Operation: S + A
474     uint64_t Result = Value + Addend;
475 
476     // AArch64 code is emitted with .rela relocations. The data already in any
477     // bits affected by the relocation on entry is garbage.
478     *TargetPtr &= 0xffc003ffU;
479     // Immediate goes in bits 21:10 of LD/ST instruction, taken
480     // from bits 11:2 of X
481     *TargetPtr |= ((Result & 0xffc) << (10 - 2));
482     break;
483   }
484   case ELF::R_AARCH64_LDST64_ABS_LO12_NC: {
485     // Operation: S + A
486     uint64_t Result = Value + Addend;
487 
488     // AArch64 code is emitted with .rela relocations. The data already in any
489     // bits affected by the relocation on entry is garbage.
490     *TargetPtr &= 0xffc003ffU;
491     // Immediate goes in bits 21:10 of LD/ST instruction, taken
492     // from bits 11:3 of X
493     *TargetPtr |= ((Result & 0xff8) << (10 - 3));
494     break;
495   }
496   }
497 }
498 
499 void RuntimeDyldELF::resolveARMRelocation(const SectionEntry &Section,
500                                           uint64_t Offset, uint32_t Value,
501                                           uint32_t Type, int32_t Addend) {
502   // TODO: Add Thumb relocations.
503   uint32_t *Placeholder =
504       reinterpret_cast<uint32_t *>(Section.ObjAddress + Offset);
505   uint32_t *TargetPtr = (uint32_t *)(Section.Address + Offset);
506   uint32_t FinalAddress = ((Section.LoadAddress + Offset) & 0xFFFFFFFF);
507   Value += Addend;
508 
509   DEBUG(dbgs() << "resolveARMRelocation, LocalAddress: "
510                << Section.Address + Offset
511                << " FinalAddress: " << format("%p", FinalAddress) << " Value: "
512                << format("%x", Value) << " Type: " << format("%x", Type)
513                << " Addend: " << format("%x", Addend) << "\n");
514 
515   switch (Type) {
516   default:
517     llvm_unreachable("Not implemented relocation type!");
518 
519   case ELF::R_ARM_NONE:
520     break;
521   // Write a 32bit value to relocation address, taking into account the
522   // implicit addend encoded in the target.
523   case ELF::R_ARM_PREL31:
524   case ELF::R_ARM_TARGET1:
525   case ELF::R_ARM_ABS32:
526     *TargetPtr = *Placeholder + Value;
527     break;
528   // Write first 16 bit of 32 bit value to the mov instruction.
529   // Last 4 bit should be shifted.
530   case ELF::R_ARM_MOVW_ABS_NC:
531     // We are not expecting any other addend in the relocation address.
532     // Using 0x000F0FFF because MOVW has its 16 bit immediate split into 2
533     // non-contiguous fields.
534     assert((*Placeholder & 0x000F0FFF) == 0);
535     Value = Value & 0xFFFF;
536     *TargetPtr = *Placeholder | (Value & 0xFFF);
537     *TargetPtr |= ((Value >> 12) & 0xF) << 16;
538     break;
539   // Write last 16 bit of 32 bit value to the mov instruction.
540   // Last 4 bit should be shifted.
541   case ELF::R_ARM_MOVT_ABS:
542     // We are not expecting any other addend in the relocation address.
543     // Use 0x000F0FFF for the same reason as R_ARM_MOVW_ABS_NC.
544     assert((*Placeholder & 0x000F0FFF) == 0);
545 
546     Value = (Value >> 16) & 0xFFFF;
547     *TargetPtr = *Placeholder | (Value & 0xFFF);
548     *TargetPtr |= ((Value >> 12) & 0xF) << 16;
549     break;
550   // Write 24 bit relative value to the branch instruction.
551   case ELF::R_ARM_PC24: // Fall through.
552   case ELF::R_ARM_CALL: // Fall through.
553   case ELF::R_ARM_JUMP24: {
554     int32_t RelValue = static_cast<int32_t>(Value - FinalAddress - 8);
555     RelValue = (RelValue & 0x03FFFFFC) >> 2;
556     assert((*TargetPtr & 0xFFFFFF) == 0xFFFFFE);
557     *TargetPtr &= 0xFF000000;
558     *TargetPtr |= RelValue;
559     break;
560   }
561   case ELF::R_ARM_PRIVATE_0:
562     // This relocation is reserved by the ARM ELF ABI for internal use. We
563     // appropriate it here to act as an R_ARM_ABS32 without any addend for use
564     // in the stubs created during JIT (which can't put an addend into the
565     // original object file).
566     *TargetPtr = Value;
567     break;
568   }
569 }
570 
571 void RuntimeDyldELF::resolveMIPSRelocation(const SectionEntry &Section,
572                                            uint64_t Offset, uint32_t Value,
573                                            uint32_t Type, int32_t Addend) {
574   uint32_t *Placeholder =
575       reinterpret_cast<uint32_t *>(Section.ObjAddress + Offset);
576   uint32_t *TargetPtr = (uint32_t *)(Section.Address + Offset);
577   Value += Addend;
578 
579   DEBUG(dbgs() << "resolveMipselocation, LocalAddress: "
580                << Section.Address + Offset << " FinalAddress: "
581                << format("%p", Section.LoadAddress + Offset) << " Value: "
582                << format("%x", Value) << " Type: " << format("%x", Type)
583                << " Addend: " << format("%x", Addend) << "\n");
584 
585   switch (Type) {
586   default:
587     llvm_unreachable("Not implemented relocation type!");
588     break;
589   case ELF::R_MIPS_32:
590     *TargetPtr = Value + (*Placeholder);
591     break;
592   case ELF::R_MIPS_26:
593     *TargetPtr = ((*Placeholder) & 0xfc000000) | ((Value & 0x0fffffff) >> 2);
594     break;
595   case ELF::R_MIPS_HI16:
596     // Get the higher 16-bits. Also add 1 if bit 15 is 1.
597     Value += ((*Placeholder) & 0x0000ffff) << 16;
598     *TargetPtr =
599         ((*Placeholder) & 0xffff0000) | (((Value + 0x8000) >> 16) & 0xffff);
600     break;
601   case ELF::R_MIPS_LO16:
602     Value += ((*Placeholder) & 0x0000ffff);
603     *TargetPtr = ((*Placeholder) & 0xffff0000) | (Value & 0xffff);
604     break;
605   case ELF::R_MIPS_UNUSED1:
606     // Similar to ELF::R_ARM_PRIVATE_0, R_MIPS_UNUSED1 and R_MIPS_UNUSED2
607     // are used for internal JIT purpose. These relocations are similar to
608     // R_MIPS_HI16 and R_MIPS_LO16, but they do not take any addend into
609     // account.
610     *TargetPtr =
611         ((*TargetPtr) & 0xffff0000) | (((Value + 0x8000) >> 16) & 0xffff);
612     break;
613   case ELF::R_MIPS_UNUSED2:
614     *TargetPtr = ((*TargetPtr) & 0xffff0000) | (Value & 0xffff);
615     break;
616   }
617 }
618 
619 // Return the .TOC. section and offset.
620 void RuntimeDyldELF::findPPC64TOCSection(ObjectImage &Obj,
621                                          ObjSectionToIDMap &LocalSections,
622                                          RelocationValueRef &Rel) {
623   // Set a default SectionID in case we do not find a TOC section below.
624   // This may happen for references to TOC base base (sym@toc, .odp
625   // relocation) without a .toc directive.  In this case just use the
626   // first section (which is usually the .odp) since the code won't
627   // reference the .toc base directly.
628   Rel.SymbolName = NULL;
629   Rel.SectionID = 0;
630 
631   // The TOC consists of sections .got, .toc, .tocbss, .plt in that
632   // order. The TOC starts where the first of these sections starts.
633   for (section_iterator si = Obj.begin_sections(), se = Obj.end_sections();
634        si != se; ++si) {
635 
636     StringRef SectionName;
637     check(si->getName(SectionName));
638 
639     if (SectionName == ".got"
640         || SectionName == ".toc"
641         || SectionName == ".tocbss"
642         || SectionName == ".plt") {
643       Rel.SectionID = findOrEmitSection(Obj, *si, false, LocalSections);
644       break;
645     }
646   }
647 
648   // Per the ppc64-elf-linux ABI, The TOC base is TOC value plus 0x8000
649   // thus permitting a full 64 Kbytes segment.
650   Rel.Addend = 0x8000;
651 }
652 
653 // Returns the sections and offset associated with the ODP entry referenced
654 // by Symbol.
655 void RuntimeDyldELF::findOPDEntrySection(ObjectImage &Obj,
656                                          ObjSectionToIDMap &LocalSections,
657                                          RelocationValueRef &Rel) {
658   // Get the ELF symbol value (st_value) to compare with Relocation offset in
659   // .opd entries
660   for (section_iterator si = Obj.begin_sections(), se = Obj.end_sections();
661        si != se; ++si) {
662     section_iterator RelSecI = si->getRelocatedSection();
663     if (RelSecI == Obj.end_sections())
664       continue;
665 
666     StringRef RelSectionName;
667     check(RelSecI->getName(RelSectionName));
668     if (RelSectionName != ".opd")
669       continue;
670 
671     for (relocation_iterator i = si->relocation_begin(),
672                              e = si->relocation_end();
673          i != e;) {
674       // The R_PPC64_ADDR64 relocation indicates the first field
675       // of a .opd entry
676       uint64_t TypeFunc;
677       check(i->getType(TypeFunc));
678       if (TypeFunc != ELF::R_PPC64_ADDR64) {
679         ++i;
680         continue;
681       }
682 
683       uint64_t TargetSymbolOffset;
684       symbol_iterator TargetSymbol = i->getSymbol();
685       check(i->getOffset(TargetSymbolOffset));
686       int64_t Addend;
687       check(getELFRelocationAddend(*i, Addend));
688 
689       ++i;
690       if (i == e)
691         break;
692 
693       // Just check if following relocation is a R_PPC64_TOC
694       uint64_t TypeTOC;
695       check(i->getType(TypeTOC));
696       if (TypeTOC != ELF::R_PPC64_TOC)
697         continue;
698 
699       // Finally compares the Symbol value and the target symbol offset
700       // to check if this .opd entry refers to the symbol the relocation
701       // points to.
702       if (Rel.Addend != (int64_t)TargetSymbolOffset)
703         continue;
704 
705       section_iterator tsi(Obj.end_sections());
706       check(TargetSymbol->getSection(tsi));
707       bool IsCode = false;
708       tsi->isText(IsCode);
709       Rel.SectionID = findOrEmitSection(Obj, (*tsi), IsCode, LocalSections);
710       Rel.Addend = (intptr_t)Addend;
711       return;
712     }
713   }
714   llvm_unreachable("Attempting to get address of ODP entry!");
715 }
716 
717 // Relocation masks following the #lo(value), #hi(value), #ha(value),
718 // #higher(value), #highera(value), #highest(value), and #highesta(value)
719 // macros defined in section 4.5.1. Relocation Types of the PPC-elf64abi
720 // document.
721 
722 static inline uint16_t applyPPClo(uint64_t value) { return value & 0xffff; }
723 
724 static inline uint16_t applyPPChi(uint64_t value) {
725   return (value >> 16) & 0xffff;
726 }
727 
728 static inline uint16_t applyPPCha (uint64_t value) {
729   return ((value + 0x8000) >> 16) & 0xffff;
730 }
731 
732 static inline uint16_t applyPPChigher(uint64_t value) {
733   return (value >> 32) & 0xffff;
734 }
735 
736 static inline uint16_t applyPPChighera (uint64_t value) {
737   return ((value + 0x8000) >> 32) & 0xffff;
738 }
739 
740 static inline uint16_t applyPPChighest(uint64_t value) {
741   return (value >> 48) & 0xffff;
742 }
743 
744 static inline uint16_t applyPPChighesta (uint64_t value) {
745   return ((value + 0x8000) >> 48) & 0xffff;
746 }
747 
748 void RuntimeDyldELF::resolvePPC64Relocation(const SectionEntry &Section,
749                                             uint64_t Offset, uint64_t Value,
750                                             uint32_t Type, int64_t Addend) {
751   uint8_t *LocalAddress = Section.Address + Offset;
752   switch (Type) {
753   default:
754     llvm_unreachable("Relocation type not implemented yet!");
755     break;
756   case ELF::R_PPC64_ADDR16:
757     writeInt16BE(LocalAddress, applyPPClo(Value + Addend));
758     break;
759   case ELF::R_PPC64_ADDR16_DS:
760     writeInt16BE(LocalAddress, applyPPClo(Value + Addend) & ~3);
761     break;
762   case ELF::R_PPC64_ADDR16_LO:
763     writeInt16BE(LocalAddress, applyPPClo(Value + Addend));
764     break;
765   case ELF::R_PPC64_ADDR16_LO_DS:
766     writeInt16BE(LocalAddress, applyPPClo(Value + Addend) & ~3);
767     break;
768   case ELF::R_PPC64_ADDR16_HI:
769     writeInt16BE(LocalAddress, applyPPChi(Value + Addend));
770     break;
771   case ELF::R_PPC64_ADDR16_HA:
772     writeInt16BE(LocalAddress, applyPPCha(Value + Addend));
773     break;
774   case ELF::R_PPC64_ADDR16_HIGHER:
775     writeInt16BE(LocalAddress, applyPPChigher(Value + Addend));
776     break;
777   case ELF::R_PPC64_ADDR16_HIGHERA:
778     writeInt16BE(LocalAddress, applyPPChighera(Value + Addend));
779     break;
780   case ELF::R_PPC64_ADDR16_HIGHEST:
781     writeInt16BE(LocalAddress, applyPPChighest(Value + Addend));
782     break;
783   case ELF::R_PPC64_ADDR16_HIGHESTA:
784     writeInt16BE(LocalAddress, applyPPChighesta(Value + Addend));
785     break;
786   case ELF::R_PPC64_ADDR14: {
787     assert(((Value + Addend) & 3) == 0);
788     // Preserve the AA/LK bits in the branch instruction
789     uint8_t aalk = *(LocalAddress + 3);
790     writeInt16BE(LocalAddress + 2, (aalk & 3) | ((Value + Addend) & 0xfffc));
791   } break;
792   case ELF::R_PPC64_REL16_LO: {
793     uint64_t FinalAddress = (Section.LoadAddress + Offset);
794     uint64_t Delta = Value - FinalAddress + Addend;
795     writeInt16BE(LocalAddress, applyPPClo(Delta));
796   } break;
797   case ELF::R_PPC64_REL16_HI: {
798     uint64_t FinalAddress = (Section.LoadAddress + Offset);
799     uint64_t Delta = Value - FinalAddress + Addend;
800     writeInt16BE(LocalAddress, applyPPChi(Delta));
801   } break;
802   case ELF::R_PPC64_REL16_HA: {
803     uint64_t FinalAddress = (Section.LoadAddress + Offset);
804     uint64_t Delta = Value - FinalAddress + Addend;
805     writeInt16BE(LocalAddress, applyPPCha(Delta));
806   } break;
807   case ELF::R_PPC64_ADDR32: {
808     int32_t Result = static_cast<int32_t>(Value + Addend);
809     if (SignExtend32<32>(Result) != Result)
810       llvm_unreachable("Relocation R_PPC64_ADDR32 overflow");
811     writeInt32BE(LocalAddress, Result);
812   } break;
813   case ELF::R_PPC64_REL24: {
814     uint64_t FinalAddress = (Section.LoadAddress + Offset);
815     int32_t delta = static_cast<int32_t>(Value - FinalAddress + Addend);
816     if (SignExtend32<24>(delta) != delta)
817       llvm_unreachable("Relocation R_PPC64_REL24 overflow");
818     // Generates a 'bl <address>' instruction
819     writeInt32BE(LocalAddress, 0x48000001 | (delta & 0x03FFFFFC));
820   } break;
821   case ELF::R_PPC64_REL32: {
822     uint64_t FinalAddress = (Section.LoadAddress + Offset);
823     int32_t delta = static_cast<int32_t>(Value - FinalAddress + Addend);
824     if (SignExtend32<32>(delta) != delta)
825       llvm_unreachable("Relocation R_PPC64_REL32 overflow");
826     writeInt32BE(LocalAddress, delta);
827   } break;
828   case ELF::R_PPC64_REL64: {
829     uint64_t FinalAddress = (Section.LoadAddress + Offset);
830     uint64_t Delta = Value - FinalAddress + Addend;
831     writeInt64BE(LocalAddress, Delta);
832   } break;
833   case ELF::R_PPC64_ADDR64:
834     writeInt64BE(LocalAddress, Value + Addend);
835     break;
836   }
837 }
838 
839 void RuntimeDyldELF::resolveSystemZRelocation(const SectionEntry &Section,
840                                               uint64_t Offset, uint64_t Value,
841                                               uint32_t Type, int64_t Addend) {
842   uint8_t *LocalAddress = Section.Address + Offset;
843   switch (Type) {
844   default:
845     llvm_unreachable("Relocation type not implemented yet!");
846     break;
847   case ELF::R_390_PC16DBL:
848   case ELF::R_390_PLT16DBL: {
849     int64_t Delta = (Value + Addend) - (Section.LoadAddress + Offset);
850     assert(int16_t(Delta / 2) * 2 == Delta && "R_390_PC16DBL overflow");
851     writeInt16BE(LocalAddress, Delta / 2);
852     break;
853   }
854   case ELF::R_390_PC32DBL:
855   case ELF::R_390_PLT32DBL: {
856     int64_t Delta = (Value + Addend) - (Section.LoadAddress + Offset);
857     assert(int32_t(Delta / 2) * 2 == Delta && "R_390_PC32DBL overflow");
858     writeInt32BE(LocalAddress, Delta / 2);
859     break;
860   }
861   case ELF::R_390_PC32: {
862     int64_t Delta = (Value + Addend) - (Section.LoadAddress + Offset);
863     assert(int32_t(Delta) == Delta && "R_390_PC32 overflow");
864     writeInt32BE(LocalAddress, Delta);
865     break;
866   }
867   case ELF::R_390_64:
868     writeInt64BE(LocalAddress, Value + Addend);
869     break;
870   }
871 }
872 
873 // The target location for the relocation is described by RE.SectionID and
874 // RE.Offset.  RE.SectionID can be used to find the SectionEntry.  Each
875 // SectionEntry has three members describing its location.
876 // SectionEntry::Address is the address at which the section has been loaded
877 // into memory in the current (host) process.  SectionEntry::LoadAddress is the
878 // address that the section will have in the target process.
879 // SectionEntry::ObjAddress is the address of the bits for this section in the
880 // original emitted object image (also in the current address space).
881 //
882 // Relocations will be applied as if the section were loaded at
883 // SectionEntry::LoadAddress, but they will be applied at an address based
884 // on SectionEntry::Address.  SectionEntry::ObjAddress will be used to refer to
885 // Target memory contents if they are required for value calculations.
886 //
887 // The Value parameter here is the load address of the symbol for the
888 // relocation to be applied.  For relocations which refer to symbols in the
889 // current object Value will be the LoadAddress of the section in which
890 // the symbol resides (RE.Addend provides additional information about the
891 // symbol location).  For external symbols, Value will be the address of the
892 // symbol in the target address space.
893 void RuntimeDyldELF::resolveRelocation(const RelocationEntry &RE,
894                                        uint64_t Value) {
895   const SectionEntry &Section = Sections[RE.SectionID];
896   return resolveRelocation(Section, RE.Offset, Value, RE.RelType, RE.Addend,
897                            RE.SymOffset);
898 }
899 
900 void RuntimeDyldELF::resolveRelocation(const SectionEntry &Section,
901                                        uint64_t Offset, uint64_t Value,
902                                        uint32_t Type, int64_t Addend,
903                                        uint64_t SymOffset) {
904   switch (Arch) {
905   case Triple::x86_64:
906     resolveX86_64Relocation(Section, Offset, Value, Type, Addend, SymOffset);
907     break;
908   case Triple::x86:
909     resolveX86Relocation(Section, Offset, (uint32_t)(Value & 0xffffffffL), Type,
910                          (uint32_t)(Addend & 0xffffffffL));
911     break;
912   case Triple::aarch64:
913   case Triple::aarch64_be:
914     resolveAArch64Relocation(Section, Offset, Value, Type, Addend);
915     break;
916   case Triple::arm: // Fall through.
917   case Triple::armeb:
918   case Triple::thumb:
919   case Triple::thumbeb:
920     resolveARMRelocation(Section, Offset, (uint32_t)(Value & 0xffffffffL), Type,
921                          (uint32_t)(Addend & 0xffffffffL));
922     break;
923   case Triple::mips: // Fall through.
924   case Triple::mipsel:
925     resolveMIPSRelocation(Section, Offset, (uint32_t)(Value & 0xffffffffL),
926                           Type, (uint32_t)(Addend & 0xffffffffL));
927     break;
928   case Triple::ppc64: // Fall through.
929   case Triple::ppc64le:
930     resolvePPC64Relocation(Section, Offset, Value, Type, Addend);
931     break;
932   case Triple::systemz:
933     resolveSystemZRelocation(Section, Offset, Value, Type, Addend);
934     break;
935   default:
936     llvm_unreachable("Unsupported CPU type!");
937   }
938 }
939 
940 relocation_iterator RuntimeDyldELF::processRelocationRef(
941     unsigned SectionID, relocation_iterator RelI, ObjectImage &Obj,
942     ObjSectionToIDMap &ObjSectionToID, const SymbolTableMap &Symbols,
943     StubMap &Stubs) {
944   uint64_t RelType;
945   Check(RelI->getType(RelType));
946   int64_t Addend;
947   Check(getELFRelocationAddend(*RelI, Addend));
948   symbol_iterator Symbol = RelI->getSymbol();
949 
950   // Obtain the symbol name which is referenced in the relocation
951   StringRef TargetName;
952   if (Symbol != Obj.end_symbols())
953     Symbol->getName(TargetName);
954   DEBUG(dbgs() << "\t\tRelType: " << RelType << " Addend: " << Addend
955                << " TargetName: " << TargetName << "\n");
956   RelocationValueRef Value;
957   // First search for the symbol in the local symbol table
958   SymbolTableMap::const_iterator lsi = Symbols.end();
959   SymbolRef::Type SymType = SymbolRef::ST_Unknown;
960   if (Symbol != Obj.end_symbols()) {
961     lsi = Symbols.find(TargetName.data());
962     Symbol->getType(SymType);
963   }
964   if (lsi != Symbols.end()) {
965     Value.SectionID = lsi->second.first;
966     Value.Offset = lsi->second.second;
967     Value.Addend = lsi->second.second + Addend;
968   } else {
969     // Search for the symbol in the global symbol table
970     SymbolTableMap::const_iterator gsi = GlobalSymbolTable.end();
971     if (Symbol != Obj.end_symbols())
972       gsi = GlobalSymbolTable.find(TargetName.data());
973     if (gsi != GlobalSymbolTable.end()) {
974       Value.SectionID = gsi->second.first;
975       Value.Offset = gsi->second.second;
976       Value.Addend = gsi->second.second + Addend;
977     } else {
978       switch (SymType) {
979       case SymbolRef::ST_Debug: {
980         // TODO: Now ELF SymbolRef::ST_Debug = STT_SECTION, it's not obviously
981         // and can be changed by another developers. Maybe best way is add
982         // a new symbol type ST_Section to SymbolRef and use it.
983         section_iterator si(Obj.end_sections());
984         Symbol->getSection(si);
985         if (si == Obj.end_sections())
986           llvm_unreachable("Symbol section not found, bad object file format!");
987         DEBUG(dbgs() << "\t\tThis is section symbol\n");
988         // Default to 'true' in case isText fails (though it never does).
989         bool isCode = true;
990         si->isText(isCode);
991         Value.SectionID = findOrEmitSection(Obj, (*si), isCode, ObjSectionToID);
992         Value.Addend = Addend;
993         break;
994       }
995       case SymbolRef::ST_Data:
996       case SymbolRef::ST_Unknown: {
997         Value.SymbolName = TargetName.data();
998         Value.Addend = Addend;
999 
1000         // Absolute relocations will have a zero symbol ID (STN_UNDEF), which
1001         // will manifest here as a NULL symbol name.
1002         // We can set this as a valid (but empty) symbol name, and rely
1003         // on addRelocationForSymbol to handle this.
1004         if (!Value.SymbolName)
1005           Value.SymbolName = "";
1006         break;
1007       }
1008       default:
1009         llvm_unreachable("Unresolved symbol type!");
1010         break;
1011       }
1012     }
1013   }
1014   uint64_t Offset;
1015   Check(RelI->getOffset(Offset));
1016 
1017   DEBUG(dbgs() << "\t\tSectionID: " << SectionID << " Offset: " << Offset
1018                << "\n");
1019   if ((Arch == Triple::aarch64 || Arch == Triple::aarch64_be) &&
1020       (RelType == ELF::R_AARCH64_CALL26 || RelType == ELF::R_AARCH64_JUMP26)) {
1021     // This is an AArch64 branch relocation, need to use a stub function.
1022     DEBUG(dbgs() << "\t\tThis is an AArch64 branch relocation.");
1023     SectionEntry &Section = Sections[SectionID];
1024 
1025     // Look for an existing stub.
1026     StubMap::const_iterator i = Stubs.find(Value);
1027     if (i != Stubs.end()) {
1028       resolveRelocation(Section, Offset, (uint64_t)Section.Address + i->second,
1029                         RelType, 0);
1030       DEBUG(dbgs() << " Stub function found\n");
1031     } else {
1032       // Create a new stub function.
1033       DEBUG(dbgs() << " Create a new stub function\n");
1034       Stubs[Value] = Section.StubOffset;
1035       uint8_t *StubTargetAddr =
1036           createStubFunction(Section.Address + Section.StubOffset);
1037 
1038       RelocationEntry REmovz_g3(SectionID, StubTargetAddr - Section.Address,
1039                                 ELF::R_AARCH64_MOVW_UABS_G3, Value.Addend);
1040       RelocationEntry REmovk_g2(SectionID, StubTargetAddr - Section.Address + 4,
1041                                 ELF::R_AARCH64_MOVW_UABS_G2_NC, Value.Addend);
1042       RelocationEntry REmovk_g1(SectionID, StubTargetAddr - Section.Address + 8,
1043                                 ELF::R_AARCH64_MOVW_UABS_G1_NC, Value.Addend);
1044       RelocationEntry REmovk_g0(SectionID,
1045                                 StubTargetAddr - Section.Address + 12,
1046                                 ELF::R_AARCH64_MOVW_UABS_G0_NC, Value.Addend);
1047 
1048       if (Value.SymbolName) {
1049         addRelocationForSymbol(REmovz_g3, Value.SymbolName);
1050         addRelocationForSymbol(REmovk_g2, Value.SymbolName);
1051         addRelocationForSymbol(REmovk_g1, Value.SymbolName);
1052         addRelocationForSymbol(REmovk_g0, Value.SymbolName);
1053       } else {
1054         addRelocationForSection(REmovz_g3, Value.SectionID);
1055         addRelocationForSection(REmovk_g2, Value.SectionID);
1056         addRelocationForSection(REmovk_g1, Value.SectionID);
1057         addRelocationForSection(REmovk_g0, Value.SectionID);
1058       }
1059       resolveRelocation(Section, Offset,
1060                         (uint64_t)Section.Address + Section.StubOffset, RelType,
1061                         0);
1062       Section.StubOffset += getMaxStubSize();
1063     }
1064   } else if (Arch == Triple::arm &&
1065              (RelType == ELF::R_ARM_PC24 || RelType == ELF::R_ARM_CALL ||
1066               RelType == ELF::R_ARM_JUMP24)) {
1067     // This is an ARM branch relocation, need to use a stub function.
1068     DEBUG(dbgs() << "\t\tThis is an ARM branch relocation.");
1069     SectionEntry &Section = Sections[SectionID];
1070 
1071     // Look for an existing stub.
1072     StubMap::const_iterator i = Stubs.find(Value);
1073     if (i != Stubs.end()) {
1074       resolveRelocation(Section, Offset, (uint64_t)Section.Address + i->second,
1075                         RelType, 0);
1076       DEBUG(dbgs() << " Stub function found\n");
1077     } else {
1078       // Create a new stub function.
1079       DEBUG(dbgs() << " Create a new stub function\n");
1080       Stubs[Value] = Section.StubOffset;
1081       uint8_t *StubTargetAddr =
1082           createStubFunction(Section.Address + Section.StubOffset);
1083       RelocationEntry RE(SectionID, StubTargetAddr - Section.Address,
1084                          ELF::R_ARM_PRIVATE_0, Value.Addend);
1085       if (Value.SymbolName)
1086         addRelocationForSymbol(RE, Value.SymbolName);
1087       else
1088         addRelocationForSection(RE, Value.SectionID);
1089 
1090       resolveRelocation(Section, Offset,
1091                         (uint64_t)Section.Address + Section.StubOffset, RelType,
1092                         0);
1093       Section.StubOffset += getMaxStubSize();
1094     }
1095   } else if ((Arch == Triple::mipsel || Arch == Triple::mips) &&
1096              RelType == ELF::R_MIPS_26) {
1097     // This is an Mips branch relocation, need to use a stub function.
1098     DEBUG(dbgs() << "\t\tThis is a Mips branch relocation.");
1099     SectionEntry &Section = Sections[SectionID];
1100     uint8_t *Target = Section.Address + Offset;
1101     uint32_t *TargetAddress = (uint32_t *)Target;
1102 
1103     // Extract the addend from the instruction.
1104     uint32_t Addend = ((*TargetAddress) & 0x03ffffff) << 2;
1105 
1106     Value.Addend += Addend;
1107 
1108     //  Look up for existing stub.
1109     StubMap::const_iterator i = Stubs.find(Value);
1110     if (i != Stubs.end()) {
1111       RelocationEntry RE(SectionID, Offset, RelType, i->second);
1112       addRelocationForSection(RE, SectionID);
1113       DEBUG(dbgs() << " Stub function found\n");
1114     } else {
1115       // Create a new stub function.
1116       DEBUG(dbgs() << " Create a new stub function\n");
1117       Stubs[Value] = Section.StubOffset;
1118       uint8_t *StubTargetAddr =
1119           createStubFunction(Section.Address + Section.StubOffset);
1120 
1121       // Creating Hi and Lo relocations for the filled stub instructions.
1122       RelocationEntry REHi(SectionID, StubTargetAddr - Section.Address,
1123                            ELF::R_MIPS_UNUSED1, Value.Addend);
1124       RelocationEntry RELo(SectionID, StubTargetAddr - Section.Address + 4,
1125                            ELF::R_MIPS_UNUSED2, Value.Addend);
1126 
1127       if (Value.SymbolName) {
1128         addRelocationForSymbol(REHi, Value.SymbolName);
1129         addRelocationForSymbol(RELo, Value.SymbolName);
1130       } else {
1131         addRelocationForSection(REHi, Value.SectionID);
1132         addRelocationForSection(RELo, Value.SectionID);
1133       }
1134 
1135       RelocationEntry RE(SectionID, Offset, RelType, Section.StubOffset);
1136       addRelocationForSection(RE, SectionID);
1137       Section.StubOffset += getMaxStubSize();
1138     }
1139   } else if (Arch == Triple::ppc64 || Arch == Triple::ppc64le) {
1140     if (RelType == ELF::R_PPC64_REL24) {
1141       // Determine ABI variant in use for this object.
1142       unsigned AbiVariant;
1143       Obj.getObjectFile()->getPlatformFlags(AbiVariant);
1144       AbiVariant &= ELF::EF_PPC64_ABI;
1145       // A PPC branch relocation will need a stub function if the target is
1146       // an external symbol (Symbol::ST_Unknown) or if the target address
1147       // is not within the signed 24-bits branch address.
1148       SectionEntry &Section = Sections[SectionID];
1149       uint8_t *Target = Section.Address + Offset;
1150       bool RangeOverflow = false;
1151       if (SymType != SymbolRef::ST_Unknown) {
1152         if (AbiVariant != 2) {
1153           // In the ELFv1 ABI, a function call may point to the .opd entry,
1154           // so the final symbol value is calculated based on the relocation
1155           // values in the .opd section.
1156           findOPDEntrySection(Obj, ObjSectionToID, Value);
1157         } else {
1158           // In the ELFv2 ABI, a function symbol may provide a local entry
1159           // point, which must be used for direct calls.
1160           uint8_t SymOther;
1161           Symbol->getOther(SymOther);
1162           Value.Addend += ELF::decodePPC64LocalEntryOffset(SymOther);
1163         }
1164         uint8_t *RelocTarget = Sections[Value.SectionID].Address + Value.Addend;
1165         int32_t delta = static_cast<int32_t>(Target - RelocTarget);
1166         // If it is within 24-bits branch range, just set the branch target
1167         if (SignExtend32<24>(delta) == delta) {
1168           RelocationEntry RE(SectionID, Offset, RelType, Value.Addend);
1169           if (Value.SymbolName)
1170             addRelocationForSymbol(RE, Value.SymbolName);
1171           else
1172             addRelocationForSection(RE, Value.SectionID);
1173         } else {
1174           RangeOverflow = true;
1175         }
1176       }
1177       if (SymType == SymbolRef::ST_Unknown || RangeOverflow == true) {
1178         // It is an external symbol (SymbolRef::ST_Unknown) or within a range
1179         // larger than 24-bits.
1180         StubMap::const_iterator i = Stubs.find(Value);
1181         if (i != Stubs.end()) {
1182           // Symbol function stub already created, just relocate to it
1183           resolveRelocation(Section, Offset,
1184                             (uint64_t)Section.Address + i->second, RelType, 0);
1185           DEBUG(dbgs() << " Stub function found\n");
1186         } else {
1187           // Create a new stub function.
1188           DEBUG(dbgs() << " Create a new stub function\n");
1189           Stubs[Value] = Section.StubOffset;
1190           uint8_t *StubTargetAddr =
1191               createStubFunction(Section.Address + Section.StubOffset,
1192                                  AbiVariant);
1193           RelocationEntry RE(SectionID, StubTargetAddr - Section.Address,
1194                              ELF::R_PPC64_ADDR64, Value.Addend);
1195 
1196           // Generates the 64-bits address loads as exemplified in section
1197           // 4.5.1 in PPC64 ELF ABI.  Note that the relocations need to
1198           // apply to the low part of the instructions, so we have to update
1199           // the offset according to the target endianness.
1200           uint64_t StubRelocOffset = StubTargetAddr - Section.Address;
1201           if (!IsTargetLittleEndian)
1202             StubRelocOffset += 2;
1203 
1204           RelocationEntry REhst(SectionID, StubRelocOffset + 0,
1205                                 ELF::R_PPC64_ADDR16_HIGHEST, Value.Addend);
1206           RelocationEntry REhr(SectionID, StubRelocOffset + 4,
1207                                ELF::R_PPC64_ADDR16_HIGHER, Value.Addend);
1208           RelocationEntry REh(SectionID, StubRelocOffset + 12,
1209                               ELF::R_PPC64_ADDR16_HI, Value.Addend);
1210           RelocationEntry REl(SectionID, StubRelocOffset + 16,
1211                               ELF::R_PPC64_ADDR16_LO, Value.Addend);
1212 
1213           if (Value.SymbolName) {
1214             addRelocationForSymbol(REhst, Value.SymbolName);
1215             addRelocationForSymbol(REhr, Value.SymbolName);
1216             addRelocationForSymbol(REh, Value.SymbolName);
1217             addRelocationForSymbol(REl, Value.SymbolName);
1218           } else {
1219             addRelocationForSection(REhst, Value.SectionID);
1220             addRelocationForSection(REhr, Value.SectionID);
1221             addRelocationForSection(REh, Value.SectionID);
1222             addRelocationForSection(REl, Value.SectionID);
1223           }
1224 
1225           resolveRelocation(Section, Offset,
1226                             (uint64_t)Section.Address + Section.StubOffset,
1227                             RelType, 0);
1228           Section.StubOffset += getMaxStubSize();
1229         }
1230         if (SymType == SymbolRef::ST_Unknown) {
1231           // Restore the TOC for external calls
1232           if (AbiVariant == 2)
1233             writeInt32BE(Target + 4, 0xE8410018); // ld r2,28(r1)
1234           else
1235             writeInt32BE(Target + 4, 0xE8410028); // ld r2,40(r1)
1236         }
1237       }
1238     } else if (RelType == ELF::R_PPC64_TOC16 ||
1239                RelType == ELF::R_PPC64_TOC16_DS ||
1240                RelType == ELF::R_PPC64_TOC16_LO ||
1241                RelType == ELF::R_PPC64_TOC16_LO_DS ||
1242                RelType == ELF::R_PPC64_TOC16_HI ||
1243                RelType == ELF::R_PPC64_TOC16_HA) {
1244       // These relocations are supposed to subtract the TOC address from
1245       // the final value.  This does not fit cleanly into the RuntimeDyld
1246       // scheme, since there may be *two* sections involved in determining
1247       // the relocation value (the section of the symbol refered to by the
1248       // relocation, and the TOC section associated with the current module).
1249       //
1250       // Fortunately, these relocations are currently only ever generated
1251       // refering to symbols that themselves reside in the TOC, which means
1252       // that the two sections are actually the same.  Thus they cancel out
1253       // and we can immediately resolve the relocation right now.
1254       switch (RelType) {
1255       case ELF::R_PPC64_TOC16: RelType = ELF::R_PPC64_ADDR16; break;
1256       case ELF::R_PPC64_TOC16_DS: RelType = ELF::R_PPC64_ADDR16_DS; break;
1257       case ELF::R_PPC64_TOC16_LO: RelType = ELF::R_PPC64_ADDR16_LO; break;
1258       case ELF::R_PPC64_TOC16_LO_DS: RelType = ELF::R_PPC64_ADDR16_LO_DS; break;
1259       case ELF::R_PPC64_TOC16_HI: RelType = ELF::R_PPC64_ADDR16_HI; break;
1260       case ELF::R_PPC64_TOC16_HA: RelType = ELF::R_PPC64_ADDR16_HA; break;
1261       default: llvm_unreachable("Wrong relocation type.");
1262       }
1263 
1264       RelocationValueRef TOCValue;
1265       findPPC64TOCSection(Obj, ObjSectionToID, TOCValue);
1266       if (Value.SymbolName || Value.SectionID != TOCValue.SectionID)
1267         llvm_unreachable("Unsupported TOC relocation.");
1268       Value.Addend -= TOCValue.Addend;
1269       resolveRelocation(Sections[SectionID], Offset, Value.Addend, RelType, 0);
1270     } else {
1271       // There are two ways to refer to the TOC address directly: either
1272       // via a ELF::R_PPC64_TOC relocation (where both symbol and addend are
1273       // ignored), or via any relocation that refers to the magic ".TOC."
1274       // symbols (in which case the addend is respected).
1275       if (RelType == ELF::R_PPC64_TOC) {
1276         RelType = ELF::R_PPC64_ADDR64;
1277         findPPC64TOCSection(Obj, ObjSectionToID, Value);
1278       } else if (TargetName == ".TOC.") {
1279         findPPC64TOCSection(Obj, ObjSectionToID, Value);
1280         Value.Addend += Addend;
1281       }
1282 
1283       RelocationEntry RE(SectionID, Offset, RelType, Value.Addend);
1284 
1285       if (Value.SymbolName)
1286         addRelocationForSymbol(RE, Value.SymbolName);
1287       else
1288         addRelocationForSection(RE, Value.SectionID);
1289     }
1290   } else if (Arch == Triple::systemz &&
1291              (RelType == ELF::R_390_PLT32DBL || RelType == ELF::R_390_GOTENT)) {
1292     // Create function stubs for both PLT and GOT references, regardless of
1293     // whether the GOT reference is to data or code.  The stub contains the
1294     // full address of the symbol, as needed by GOT references, and the
1295     // executable part only adds an overhead of 8 bytes.
1296     //
1297     // We could try to conserve space by allocating the code and data
1298     // parts of the stub separately.  However, as things stand, we allocate
1299     // a stub for every relocation, so using a GOT in JIT code should be
1300     // no less space efficient than using an explicit constant pool.
1301     DEBUG(dbgs() << "\t\tThis is a SystemZ indirect relocation.");
1302     SectionEntry &Section = Sections[SectionID];
1303 
1304     // Look for an existing stub.
1305     StubMap::const_iterator i = Stubs.find(Value);
1306     uintptr_t StubAddress;
1307     if (i != Stubs.end()) {
1308       StubAddress = uintptr_t(Section.Address) + i->second;
1309       DEBUG(dbgs() << " Stub function found\n");
1310     } else {
1311       // Create a new stub function.
1312       DEBUG(dbgs() << " Create a new stub function\n");
1313 
1314       uintptr_t BaseAddress = uintptr_t(Section.Address);
1315       uintptr_t StubAlignment = getStubAlignment();
1316       StubAddress = (BaseAddress + Section.StubOffset + StubAlignment - 1) &
1317                     -StubAlignment;
1318       unsigned StubOffset = StubAddress - BaseAddress;
1319 
1320       Stubs[Value] = StubOffset;
1321       createStubFunction((uint8_t *)StubAddress);
1322       RelocationEntry RE(SectionID, StubOffset + 8, ELF::R_390_64,
1323                          Value.Addend - Addend);
1324       if (Value.SymbolName)
1325         addRelocationForSymbol(RE, Value.SymbolName);
1326       else
1327         addRelocationForSection(RE, Value.SectionID);
1328       Section.StubOffset = StubOffset + getMaxStubSize();
1329     }
1330 
1331     if (RelType == ELF::R_390_GOTENT)
1332       resolveRelocation(Section, Offset, StubAddress + 8, ELF::R_390_PC32DBL,
1333                         Addend);
1334     else
1335       resolveRelocation(Section, Offset, StubAddress, RelType, Addend);
1336   } else if (Arch == Triple::x86_64 && RelType == ELF::R_X86_64_PLT32) {
1337     // The way the PLT relocations normally work is that the linker allocates
1338     // the
1339     // PLT and this relocation makes a PC-relative call into the PLT.  The PLT
1340     // entry will then jump to an address provided by the GOT.  On first call,
1341     // the
1342     // GOT address will point back into PLT code that resolves the symbol. After
1343     // the first call, the GOT entry points to the actual function.
1344     //
1345     // For local functions we're ignoring all of that here and just replacing
1346     // the PLT32 relocation type with PC32, which will translate the relocation
1347     // into a PC-relative call directly to the function. For external symbols we
1348     // can't be sure the function will be within 2^32 bytes of the call site, so
1349     // we need to create a stub, which calls into the GOT.  This case is
1350     // equivalent to the usual PLT implementation except that we use the stub
1351     // mechanism in RuntimeDyld (which puts stubs at the end of the section)
1352     // rather than allocating a PLT section.
1353     if (Value.SymbolName) {
1354       // This is a call to an external function.
1355       // Look for an existing stub.
1356       SectionEntry &Section = Sections[SectionID];
1357       StubMap::const_iterator i = Stubs.find(Value);
1358       uintptr_t StubAddress;
1359       if (i != Stubs.end()) {
1360         StubAddress = uintptr_t(Section.Address) + i->second;
1361         DEBUG(dbgs() << " Stub function found\n");
1362       } else {
1363         // Create a new stub function (equivalent to a PLT entry).
1364         DEBUG(dbgs() << " Create a new stub function\n");
1365 
1366         uintptr_t BaseAddress = uintptr_t(Section.Address);
1367         uintptr_t StubAlignment = getStubAlignment();
1368         StubAddress = (BaseAddress + Section.StubOffset + StubAlignment - 1) &
1369                       -StubAlignment;
1370         unsigned StubOffset = StubAddress - BaseAddress;
1371         Stubs[Value] = StubOffset;
1372         createStubFunction((uint8_t *)StubAddress);
1373 
1374         // Create a GOT entry for the external function.
1375         GOTEntries.push_back(Value);
1376 
1377         // Make our stub function a relative call to the GOT entry.
1378         RelocationEntry RE(SectionID, StubOffset + 2, ELF::R_X86_64_GOTPCREL,
1379                            -4);
1380         addRelocationForSymbol(RE, Value.SymbolName);
1381 
1382         // Bump our stub offset counter
1383         Section.StubOffset = StubOffset + getMaxStubSize();
1384       }
1385 
1386       // Make the target call a call into the stub table.
1387       resolveRelocation(Section, Offset, StubAddress, ELF::R_X86_64_PC32,
1388                         Addend);
1389     } else {
1390       RelocationEntry RE(SectionID, Offset, ELF::R_X86_64_PC32, Value.Addend,
1391                          Value.Offset);
1392       addRelocationForSection(RE, Value.SectionID);
1393     }
1394   } else {
1395     if (Arch == Triple::x86_64 && RelType == ELF::R_X86_64_GOTPCREL) {
1396       GOTEntries.push_back(Value);
1397     }
1398     RelocationEntry RE(SectionID, Offset, RelType, Value.Addend, Value.Offset);
1399     if (Value.SymbolName)
1400       addRelocationForSymbol(RE, Value.SymbolName);
1401     else
1402       addRelocationForSection(RE, Value.SectionID);
1403   }
1404   return ++RelI;
1405 }
1406 
1407 void RuntimeDyldELF::updateGOTEntries(StringRef Name, uint64_t Addr) {
1408 
1409   SmallVectorImpl<std::pair<SID, GOTRelocations>>::iterator it;
1410   SmallVectorImpl<std::pair<SID, GOTRelocations>>::iterator end = GOTs.end();
1411 
1412   for (it = GOTs.begin(); it != end; ++it) {
1413     GOTRelocations &GOTEntries = it->second;
1414     for (int i = 0, e = GOTEntries.size(); i != e; ++i) {
1415       if (GOTEntries[i].SymbolName != nullptr &&
1416           GOTEntries[i].SymbolName == Name) {
1417         GOTEntries[i].Offset = Addr;
1418       }
1419     }
1420   }
1421 }
1422 
1423 size_t RuntimeDyldELF::getGOTEntrySize() {
1424   // We don't use the GOT in all of these cases, but it's essentially free
1425   // to put them all here.
1426   size_t Result = 0;
1427   switch (Arch) {
1428   case Triple::x86_64:
1429   case Triple::aarch64:
1430   case Triple::aarch64_be:
1431   case Triple::ppc64:
1432   case Triple::ppc64le:
1433   case Triple::systemz:
1434     Result = sizeof(uint64_t);
1435     break;
1436   case Triple::x86:
1437   case Triple::arm:
1438   case Triple::thumb:
1439   case Triple::mips:
1440   case Triple::mipsel:
1441     Result = sizeof(uint32_t);
1442     break;
1443   default:
1444     llvm_unreachable("Unsupported CPU type!");
1445   }
1446   return Result;
1447 }
1448 
1449 uint64_t RuntimeDyldELF::findGOTEntry(uint64_t LoadAddress, uint64_t Offset) {
1450 
1451   const size_t GOTEntrySize = getGOTEntrySize();
1452 
1453   SmallVectorImpl<std::pair<SID, GOTRelocations>>::const_iterator it;
1454   SmallVectorImpl<std::pair<SID, GOTRelocations>>::const_iterator end =
1455       GOTs.end();
1456 
1457   int GOTIndex = -1;
1458   for (it = GOTs.begin(); it != end; ++it) {
1459     SID GOTSectionID = it->first;
1460     const GOTRelocations &GOTEntries = it->second;
1461 
1462     // Find the matching entry in our vector.
1463     uint64_t SymbolOffset = 0;
1464     for (int i = 0, e = GOTEntries.size(); i != e; ++i) {
1465       if (!GOTEntries[i].SymbolName) {
1466         if (getSectionLoadAddress(GOTEntries[i].SectionID) == LoadAddress &&
1467             GOTEntries[i].Offset == Offset) {
1468           GOTIndex = i;
1469           SymbolOffset = GOTEntries[i].Offset;
1470           break;
1471         }
1472       } else {
1473         // GOT entries for external symbols use the addend as the address when
1474         // the external symbol has been resolved.
1475         if (GOTEntries[i].Offset == LoadAddress) {
1476           GOTIndex = i;
1477           // Don't use the Addend here.  The relocation handler will use it.
1478           break;
1479         }
1480       }
1481     }
1482 
1483     if (GOTIndex != -1) {
1484       if (GOTEntrySize == sizeof(uint64_t)) {
1485         uint64_t *LocalGOTAddr = (uint64_t *)getSectionAddress(GOTSectionID);
1486         // Fill in this entry with the address of the symbol being referenced.
1487         LocalGOTAddr[GOTIndex] = LoadAddress + SymbolOffset;
1488       } else {
1489         uint32_t *LocalGOTAddr = (uint32_t *)getSectionAddress(GOTSectionID);
1490         // Fill in this entry with the address of the symbol being referenced.
1491         LocalGOTAddr[GOTIndex] = (uint32_t)(LoadAddress + SymbolOffset);
1492       }
1493 
1494       // Calculate the load address of this entry
1495       return getSectionLoadAddress(GOTSectionID) + (GOTIndex * GOTEntrySize);
1496     }
1497   }
1498 
1499   assert(GOTIndex != -1 && "Unable to find requested GOT entry.");
1500   return 0;
1501 }
1502 
1503 void RuntimeDyldELF::finalizeLoad(ObjectImage &ObjImg,
1504                                   ObjSectionToIDMap &SectionMap) {
1505   // If necessary, allocate the global offset table
1506   if (MemMgr) {
1507     // Allocate the GOT if necessary
1508     size_t numGOTEntries = GOTEntries.size();
1509     if (numGOTEntries != 0) {
1510       // Allocate memory for the section
1511       unsigned SectionID = Sections.size();
1512       size_t TotalSize = numGOTEntries * getGOTEntrySize();
1513       uint8_t *Addr = MemMgr->allocateDataSection(TotalSize, getGOTEntrySize(),
1514                                                   SectionID, ".got", false);
1515       if (!Addr)
1516         report_fatal_error("Unable to allocate memory for GOT!");
1517 
1518       GOTs.push_back(std::make_pair(SectionID, GOTEntries));
1519       Sections.push_back(SectionEntry(".got", Addr, TotalSize, 0));
1520       // For now, initialize all GOT entries to zero.  We'll fill them in as
1521       // needed when GOT-based relocations are applied.
1522       memset(Addr, 0, TotalSize);
1523     }
1524   } else {
1525     report_fatal_error("Unable to allocate memory for GOT!");
1526   }
1527 
1528   // Look for and record the EH frame section.
1529   ObjSectionToIDMap::iterator i, e;
1530   for (i = SectionMap.begin(), e = SectionMap.end(); i != e; ++i) {
1531     const SectionRef &Section = i->first;
1532     StringRef Name;
1533     Section.getName(Name);
1534     if (Name == ".eh_frame") {
1535       UnregisteredEHFrameSections.push_back(i->second);
1536       break;
1537     }
1538   }
1539 }
1540 
1541 bool RuntimeDyldELF::isCompatibleFormat(const ObjectBuffer *Buffer) const {
1542   if (Buffer->getBufferSize() < strlen(ELF::ElfMagic))
1543     return false;
1544   return (memcmp(Buffer->getBufferStart(), ELF::ElfMagic,
1545                  strlen(ELF::ElfMagic))) == 0;
1546 }
1547 
1548 bool RuntimeDyldELF::isCompatibleFile(const object::ObjectFile *Obj) const {
1549   return Obj->isELF();
1550 }
1551 
1552 } // namespace llvm
1553