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 ErrorOr<ObjectFile *> 21 ObjectFile::createELFObjectFile(std::unique_ptr<MemoryBuffer> &Obj) { 22 std::pair<unsigned char, unsigned char> Ident = 23 getElfArchType(Obj->getBuffer()); 24 std::size_t MaxAlignment = 25 1ULL << countTrailingZeros(uintptr_t(Obj->getBufferStart())); 26 27 std::error_code EC; 28 std::unique_ptr<ObjectFile> R; 29 if (Ident.first == ELF::ELFCLASS32 && Ident.second == ELF::ELFDATA2LSB) 30 #if !LLVM_IS_UNALIGNED_ACCESS_FAST 31 if (MaxAlignment >= 4) 32 R.reset(new ELFObjectFile<ELFType<support::little, 4, false>>( 33 std::move(Obj), EC)); 34 else 35 #endif 36 if (MaxAlignment >= 2) 37 R.reset(new ELFObjectFile<ELFType<support::little, 2, false>>( 38 std::move(Obj), EC)); 39 else 40 return object_error::parse_failed; 41 else if (Ident.first == ELF::ELFCLASS32 && Ident.second == ELF::ELFDATA2MSB) 42 #if !LLVM_IS_UNALIGNED_ACCESS_FAST 43 if (MaxAlignment >= 4) 44 R.reset(new ELFObjectFile<ELFType<support::big, 4, false>>(std::move(Obj), 45 EC)); 46 else 47 #endif 48 if (MaxAlignment >= 2) 49 R.reset(new ELFObjectFile<ELFType<support::big, 2, false>>(std::move(Obj), 50 EC)); 51 else 52 return object_error::parse_failed; 53 else if (Ident.first == ELF::ELFCLASS64 && Ident.second == ELF::ELFDATA2MSB) 54 #if !LLVM_IS_UNALIGNED_ACCESS_FAST 55 if (MaxAlignment >= 8) 56 R.reset(new ELFObjectFile<ELFType<support::big, 8, true>>(std::move(Obj), 57 EC)); 58 else 59 #endif 60 if (MaxAlignment >= 2) 61 R.reset(new ELFObjectFile<ELFType<support::big, 2, true>>(std::move(Obj), 62 EC)); 63 else 64 return object_error::parse_failed; 65 else if (Ident.first == ELF::ELFCLASS64 && Ident.second == ELF::ELFDATA2LSB) { 66 #if !LLVM_IS_UNALIGNED_ACCESS_FAST 67 if (MaxAlignment >= 8) 68 R.reset(new ELFObjectFile<ELFType<support::little, 8, true>>( 69 std::move(Obj), EC)); 70 else 71 #endif 72 if (MaxAlignment >= 2) 73 R.reset(new ELFObjectFile<ELFType<support::little, 2, true>>( 74 std::move(Obj), EC)); 75 else 76 return object_error::parse_failed; 77 } 78 else 79 llvm_unreachable("Buffer is not an ELF object file!"); 80 81 if (EC) 82 return EC; 83 return R.release(); 84 } 85 86 } // end namespace llvm 87
