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 // Creates an in-memory object-file by default: createELFObjectFile(Buffer) 21 ObjectFile *ObjectFile::createELFObjectFile(MemoryBuffer *Object) { 22 std::pair<unsigned char, unsigned char> Ident = getElfArchType(Object); 23 error_code ec; 24 25 std::size_t MaxAlignment = 26 1ULL << countTrailingZeros(uintptr_t(Object->getBufferStart())); 27 28 if (Ident.first == ELF::ELFCLASS32 && Ident.second == ELF::ELFDATA2LSB) 29 #if !LLVM_IS_UNALIGNED_ACCESS_FAST 30 if (MaxAlignment >= 4) 31 return new ELFObjectFile<ELFType<support::little, 4, false> >(Object, ec); 32 else 33 #endif 34 if (MaxAlignment >= 2) 35 return new ELFObjectFile<ELFType<support::little, 2, false> >(Object, ec); 36 else 37 llvm_unreachable("Invalid alignment for ELF file!"); 38 else if (Ident.first == ELF::ELFCLASS32 && Ident.second == ELF::ELFDATA2MSB) 39 #if !LLVM_IS_UNALIGNED_ACCESS_FAST 40 if (MaxAlignment >= 4) 41 return new ELFObjectFile<ELFType<support::big, 4, false> >(Object, ec); 42 else 43 #endif 44 if (MaxAlignment >= 2) 45 return new ELFObjectFile<ELFType<support::big, 2, false> >(Object, ec); 46 else 47 llvm_unreachable("Invalid alignment for ELF file!"); 48 else if (Ident.first == ELF::ELFCLASS64 && Ident.second == ELF::ELFDATA2MSB) 49 #if !LLVM_IS_UNALIGNED_ACCESS_FAST 50 if (MaxAlignment >= 8) 51 return new ELFObjectFile<ELFType<support::big, 8, true> >(Object, ec); 52 else 53 #endif 54 if (MaxAlignment >= 2) 55 return new ELFObjectFile<ELFType<support::big, 2, true> >(Object, ec); 56 else 57 llvm_unreachable("Invalid alignment for ELF file!"); 58 else if (Ident.first == ELF::ELFCLASS64 && Ident.second == ELF::ELFDATA2LSB) { 59 #if !LLVM_IS_UNALIGNED_ACCESS_FAST 60 if (MaxAlignment >= 8) 61 return new ELFObjectFile<ELFType<support::little, 8, true> >(Object, ec); 62 else 63 #endif 64 if (MaxAlignment >= 2) 65 return new ELFObjectFile<ELFType<support::little, 2, true> >(Object, ec); 66 else 67 llvm_unreachable("Invalid alignment for ELF file!"); 68 } 69 70 report_fatal_error("Buffer is not an ELF object file!"); 71 } 72 73 } // end namespace llvm 74