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/ELF.h" 15 #include "llvm/Support/MathExtras.h" 16 17 namespace llvm { 18 19 using namespace object; 20 21 // Creates an in-memory object-file by default: createELFObjectFile(Buffer) 22 ObjectFile *ObjectFile::createELFObjectFile(MemoryBuffer *Object) { 23 std::pair<unsigned char, unsigned char> Ident = getElfArchType(Object); 24 error_code ec; 25 26 std::size_t MaxAlignment = 27 1ULL << CountTrailingZeros_64(uintptr_t(Object->getBufferStart())); 28 29 if (Ident.first == ELF::ELFCLASS32 && Ident.second == ELF::ELFDATA2LSB) 30 #if !LLVM_IS_UNALIGNED_ACCESS_FAST 31 if (MaxAlignment >= 4) 32 return new ELFObjectFile<ELFType<support::little, 4, false> >(Object, ec); 33 else 34 #endif 35 if (MaxAlignment >= 2) 36 return new ELFObjectFile<ELFType<support::little, 2, false> >(Object, ec); 37 else 38 llvm_unreachable("Invalid alignment for ELF file!"); 39 else if (Ident.first == ELF::ELFCLASS32 && Ident.second == ELF::ELFDATA2MSB) 40 #if !LLVM_IS_UNALIGNED_ACCESS_FAST 41 if (MaxAlignment >= 4) 42 return new ELFObjectFile<ELFType<support::big, 4, false> >(Object, ec); 43 else 44 #endif 45 if (MaxAlignment >= 2) 46 return new ELFObjectFile<ELFType<support::big, 2, false> >(Object, ec); 47 else 48 llvm_unreachable("Invalid alignment for ELF file!"); 49 else if (Ident.first == ELF::ELFCLASS64 && Ident.second == ELF::ELFDATA2MSB) 50 #if !LLVM_IS_UNALIGNED_ACCESS_FAST 51 if (MaxAlignment >= 8) 52 return new ELFObjectFile<ELFType<support::big, 8, true> >(Object, ec); 53 else 54 #endif 55 if (MaxAlignment >= 2) 56 return new ELFObjectFile<ELFType<support::big, 2, true> >(Object, ec); 57 else 58 llvm_unreachable("Invalid alignment for ELF file!"); 59 else if (Ident.first == ELF::ELFCLASS64 && Ident.second == ELF::ELFDATA2LSB) { 60 #if !LLVM_IS_UNALIGNED_ACCESS_FAST 61 if (MaxAlignment >= 8) 62 return new ELFObjectFile<ELFType<support::little, 8, true> >(Object, ec); 63 else 64 #endif 65 if (MaxAlignment >= 2) 66 return new ELFObjectFile<ELFType<support::little, 2, true> >(Object, ec); 67 else 68 llvm_unreachable("Invalid alignment for ELF file!"); 69 } 70 71 report_fatal_error("Buffer is not an ELF object file!"); 72 } 73 74 } // end namespace llvm 75