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 #include <ctype.h>
18
19 namespace llvm {
20
21 using namespace object;
22
23 // Creates an in-memory object-file by default: createELFObjectFile(Buffer)
createELFObjectFile(MemoryBuffer * Object)24 ObjectFile *ObjectFile::createELFObjectFile(MemoryBuffer *Object) {
25 std::pair<unsigned char, unsigned char> Ident = getElfArchType(Object);
26 error_code ec;
27
28 std::size_t MaxAlignment =
29 1ULL << CountTrailingZeros_64(uintptr_t(Object->getBufferStart()));
30
31 if (Ident.first == ELF::ELFCLASS32 && Ident.second == ELF::ELFDATA2LSB)
32 #if !LLVM_IS_UNALIGNED_ACCESS_FAST
33 if (MaxAlignment >= 4)
34 return new ELFObjectFile<ELFType<support::little, 4, false> >(Object, ec);
35 else
36 #endif
37 if (MaxAlignment >= 2)
38 return new ELFObjectFile<ELFType<support::little, 2, false> >(Object, ec);
39 else
40 llvm_unreachable("Invalid alignment for ELF file!");
41 else if (Ident.first == ELF::ELFCLASS32 && Ident.second == ELF::ELFDATA2MSB)
42 #if !LLVM_IS_UNALIGNED_ACCESS_FAST
43 if (MaxAlignment >= 4)
44 return new ELFObjectFile<ELFType<support::big, 4, false> >(Object, ec);
45 else
46 #endif
47 if (MaxAlignment >= 2)
48 return new ELFObjectFile<ELFType<support::big, 2, false> >(Object, ec);
49 else
50 llvm_unreachable("Invalid alignment for ELF file!");
51 else if (Ident.first == ELF::ELFCLASS64 && Ident.second == ELF::ELFDATA2MSB)
52 #if !LLVM_IS_UNALIGNED_ACCESS_FAST
53 if (MaxAlignment >= 8)
54 return new ELFObjectFile<ELFType<support::big, 8, true> >(Object, ec);
55 else
56 #endif
57 if (MaxAlignment >= 2)
58 return new ELFObjectFile<ELFType<support::big, 2, true> >(Object, ec);
59 else
60 llvm_unreachable("Invalid alignment for ELF file!");
61 else if (Ident.first == ELF::ELFCLASS64 && Ident.second == ELF::ELFDATA2LSB) {
62 #if !LLVM_IS_UNALIGNED_ACCESS_FAST
63 if (MaxAlignment >= 8)
64 return new ELFObjectFile<ELFType<support::little, 8, true> >(Object, ec);
65 else
66 #endif
67 if (MaxAlignment >= 2)
68 return new ELFObjectFile<ELFType<support::little, 2, true> >(Object, ec);
69 else
70 llvm_unreachable("Invalid alignment for ELF file!");
71 }
72
73 report_fatal_error("Buffer is not an ELF object file!");
74 }
75
76 } // end namespace llvm
77