1 //===- ELFObjectFile.cpp - ELF object file implementation -------*- C++ -*-===//
3 // The LLVM Compiler Infrastructure
5 // This file is distributed under the University of Illinois Open Source
6 // License. See LICENSE.TXT for details.
8 //===----------------------------------------------------------------------===//
10 // Part of the ELFObjectFile class implementation.
12 //===----------------------------------------------------------------------===//
14 #include "llvm/Object/ELFObjectFile.h"
15 #include "llvm/Support/MathExtras.h"
18 using namespace object;
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);
25 std::size_t MaxAlignment =
26 1ULL << countTrailingZeros(uintptr_t(Object->getBufferStart()));
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);
34 if (MaxAlignment >= 2)
35 return new ELFObjectFile<ELFType<support::little, 2, false> >(Object, ec);
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);
44 if (MaxAlignment >= 2)
45 return new ELFObjectFile<ELFType<support::big, 2, false> >(Object, ec);
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);
54 if (MaxAlignment >= 2)
55 return new ELFObjectFile<ELFType<support::big, 2, true> >(Object, ec);
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);
64 if (MaxAlignment >= 2)
65 return new ELFObjectFile<ELFType<support::little, 2, true> >(Object, ec);
67 llvm_unreachable("Invalid alignment for ELF file!");
70 report_fatal_error("Buffer is not an ELF object file!");
73 } // end namespace llvm