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/ELF.h"
15 #include "llvm/Support/MathExtras.h"
19 using namespace object;
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);
26 std::size_t MaxAlignment =
27 1ULL << countTrailingZeros(uintptr_t(Object->getBufferStart()));
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);
35 if (MaxAlignment >= 2)
36 return new ELFObjectFile<ELFType<support::little, 2, false> >(Object, ec);
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);
45 if (MaxAlignment >= 2)
46 return new ELFObjectFile<ELFType<support::big, 2, false> >(Object, ec);
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);
55 if (MaxAlignment >= 2)
56 return new ELFObjectFile<ELFType<support::big, 2, true> >(Object, ec);
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);
65 if (MaxAlignment >= 2)
66 return new ELFObjectFile<ELFType<support::little, 2, true> >(Object, ec);
68 llvm_unreachable("Invalid alignment for ELF file!");
71 report_fatal_error("Buffer is not an ELF object file!");
74 } // end namespace llvm