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 *>
createELFObjectFile(std::unique_ptr<MemoryBuffer> & Obj)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