1 //===- ELFObjectFile.cpp - 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 // Part of the ELFObjectFile class implementation. 11 // 12 //===----------------------------------------------------------------------===// 13 14 #include "llvm/Object/ELFObjectFile.h" 15 #include "llvm/Support/MathExtras.h" 16 17 namespace llvm { 18 using namespace object; 19 20 ELFObjectFileBase::ELFObjectFileBase(unsigned int Type, MemoryBufferRef Source) 21 : ObjectFile(Type, Source) {} 22 23 ErrorOr<std::unique_ptr<ObjectFile>> 24 ObjectFile::createELFObjectFile(MemoryBufferRef Obj) { 25 std::pair<unsigned char, unsigned char> Ident = 26 getElfArchType(Obj.getBuffer()); 27 std::size_t MaxAlignment = 28 1ULL << countTrailingZeros(uintptr_t(Obj.getBufferStart())); 29 30 std::error_code EC; 31 std::unique_ptr<ObjectFile> R; 32 if (Ident.first == ELF::ELFCLASS32 && Ident.second == ELF::ELFDATA2LSB) 33 #if !LLVM_IS_UNALIGNED_ACCESS_FAST 34 if (MaxAlignment >= 4) 35 R.reset(new ELFObjectFile<ELFType<support::little, 4, false>>(Obj, EC)); 36 else 37 #endif 38 if (MaxAlignment >= 2) 39 R.reset(new ELFObjectFile<ELFType<support::little, 2, false>>(Obj, EC)); 40 else 41 return object_error::parse_failed; 42 else if (Ident.first == ELF::ELFCLASS32 && Ident.second == ELF::ELFDATA2MSB) 43 #if !LLVM_IS_UNALIGNED_ACCESS_FAST 44 if (MaxAlignment >= 4) 45 R.reset(new ELFObjectFile<ELFType<support::big, 4, false>>(Obj, EC)); 46 else 47 #endif 48 if (MaxAlignment >= 2) 49 R.reset(new ELFObjectFile<ELFType<support::big, 2, false>>(Obj, EC)); 50 else 51 return object_error::parse_failed; 52 else if (Ident.first == ELF::ELFCLASS64 && Ident.second == ELF::ELFDATA2MSB) 53 #if !LLVM_IS_UNALIGNED_ACCESS_FAST 54 if (MaxAlignment >= 8) 55 R.reset(new ELFObjectFile<ELFType<support::big, 8, true>>(Obj, EC)); 56 else 57 #endif 58 if (MaxAlignment >= 2) 59 R.reset(new ELFObjectFile<ELFType<support::big, 2, true>>(Obj, EC)); 60 else 61 return object_error::parse_failed; 62 else if (Ident.first == ELF::ELFCLASS64 && Ident.second == ELF::ELFDATA2LSB) { 63 #if !LLVM_IS_UNALIGNED_ACCESS_FAST 64 if (MaxAlignment >= 8) 65 R.reset(new ELFObjectFile<ELFType<support::little, 8, true>>(Obj, EC)); 66 else 67 #endif 68 if (MaxAlignment >= 2) 69 R.reset(new ELFObjectFile<ELFType<support::little, 2, true>>(Obj, EC)); 70 else 71 return object_error::parse_failed; 72 } 73 else 74 llvm_unreachable("Buffer is not an ELF object file!"); 75 76 if (EC) 77 return EC; 78 return std::move(R); 79 } 80 81 } // end namespace llvm 82
