1 //===- MachOUniversal.cpp - Mach-O universal binary -------------*- 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 // This file defines the MachOUniversalBinary class.
11 //
12 //===----------------------------------------------------------------------===//
13 
14 #include "llvm/Object/MachOUniversal.h"
15 #include "llvm/Object/MachO.h"
16 #include "llvm/Object/ObjectFile.h"
17 #include "llvm/Object/Archive.h"
18 #include "llvm/Support/Casting.h"
19 #include "llvm/Support/Host.h"
20 #include "llvm/Support/MemoryBuffer.h"
21 
22 using namespace llvm;
23 using namespace object;
24 
25 template<typename T>
26 static void SwapStruct(T &Value);
27 
28 template<>
29 void SwapStruct(MachO::fat_header &H) {
30   sys::swapByteOrder(H.magic);
31   sys::swapByteOrder(H.nfat_arch);
32 }
33 
34 template<>
35 void SwapStruct(MachO::fat_arch &H) {
36   sys::swapByteOrder(H.cputype);
37   sys::swapByteOrder(H.cpusubtype);
38   sys::swapByteOrder(H.offset);
39   sys::swapByteOrder(H.size);
40   sys::swapByteOrder(H.align);
41 }
42 
43 template<typename T>
44 static T getUniversalBinaryStruct(const char *Ptr) {
45   T Res;
46   memcpy(&Res, Ptr, sizeof(T));
47   // Universal binary headers have big-endian byte order.
48   if (sys::IsLittleEndianHost)
49     SwapStruct(Res);
50   return Res;
51 }
52 
53 MachOUniversalBinary::ObjectForArch::ObjectForArch(
54     const MachOUniversalBinary *Parent, uint32_t Index)
55     : Parent(Parent), Index(Index) {
56   if (!Parent || Index > Parent->getNumberOfObjects()) {
57     clear();
58   } else {
59     // Parse object header.
60     StringRef ParentData = Parent->getData();
61     const char *HeaderPos = ParentData.begin() + sizeof(MachO::fat_header) +
62                             Index * sizeof(MachO::fat_arch);
63     Header = getUniversalBinaryStruct<MachO::fat_arch>(HeaderPos);
64     if (ParentData.size() < Header.offset + Header.size) {
65       clear();
66     }
67   }
68 }
69 
70 std::error_code MachOUniversalBinary::ObjectForArch::getAsObjectFile(
71     std::unique_ptr<ObjectFile> &Result) const {
72   if (Parent) {
73     StringRef ParentData = Parent->getData();
74     StringRef ObjectData = ParentData.substr(Header.offset, Header.size);
75     std::string ObjectName =
76         Parent->getFileName().str() + ":" +
77         Triple::getArchTypeName(MachOObjectFile::getArch(Header.cputype));
78     MemoryBuffer *ObjBuffer = MemoryBuffer::getMemBuffer(
79         ObjectData, ObjectName, false);
80     ErrorOr<ObjectFile *> Obj = ObjectFile::createMachOObjectFile(ObjBuffer);
81     if (std::error_code EC = Obj.getError())
82       return EC;
83     Result.reset(Obj.get());
84     return object_error::success;
85   }
86   return object_error::parse_failed;
87 }
88 
89 std::error_code MachOUniversalBinary::ObjectForArch::getAsArchive(
90     std::unique_ptr<Archive> &Result) const {
91   if (Parent) {
92     StringRef ParentData = Parent->getData();
93     StringRef ObjectData = ParentData.substr(Header.offset, Header.size);
94     std::string ObjectName =
95         Parent->getFileName().str() + ":" +
96         Triple::getArchTypeName(MachOObjectFile::getArch(Header.cputype));
97     MemoryBuffer *ObjBuffer = MemoryBuffer::getMemBuffer(
98         ObjectData, ObjectName, false);
99     ErrorOr<Archive *> Obj = Archive::create(ObjBuffer);
100     if (std::error_code EC = Obj.getError())
101       return EC;
102     Result.reset(Obj.get());
103     return object_error::success;
104   }
105   return object_error::parse_failed;
106 }
107 
108 void MachOUniversalBinary::anchor() { }
109 
110 ErrorOr<MachOUniversalBinary *>
111 MachOUniversalBinary::create(MemoryBuffer *Source) {
112   std::error_code EC;
113   std::unique_ptr<MachOUniversalBinary> Ret(
114       new MachOUniversalBinary(Source, EC));
115   if (EC)
116     return EC;
117   return Ret.release();
118 }
119 
120 MachOUniversalBinary::MachOUniversalBinary(MemoryBuffer *Source,
121                                            std::error_code &ec)
122     : Binary(Binary::ID_MachOUniversalBinary, Source), NumberOfObjects(0) {
123   if (Source->getBufferSize() < sizeof(MachO::fat_header)) {
124     ec = object_error::invalid_file_type;
125     return;
126   }
127   // Check for magic value and sufficient header size.
128   StringRef Buf = getData();
129   MachO::fat_header H= getUniversalBinaryStruct<MachO::fat_header>(Buf.begin());
130   NumberOfObjects = H.nfat_arch;
131   uint32_t MinSize = sizeof(MachO::fat_header) +
132                      sizeof(MachO::fat_arch) * NumberOfObjects;
133   if (H.magic != MachO::FAT_MAGIC || Buf.size() < MinSize) {
134     ec = object_error::parse_failed;
135     return;
136   }
137   ec = object_error::success;
138 }
139 
140 static bool getCTMForArch(Triple::ArchType Arch, MachO::CPUType &CTM) {
141   switch (Arch) {
142     case Triple::x86:    CTM = MachO::CPU_TYPE_I386; return true;
143     case Triple::x86_64: CTM = MachO::CPU_TYPE_X86_64; return true;
144     case Triple::arm:    CTM = MachO::CPU_TYPE_ARM; return true;
145     case Triple::sparc:  CTM = MachO::CPU_TYPE_SPARC; return true;
146     case Triple::ppc:    CTM = MachO::CPU_TYPE_POWERPC; return true;
147     case Triple::ppc64:  CTM = MachO::CPU_TYPE_POWERPC64; return true;
148     default: return false;
149   }
150 }
151 
152 std::error_code MachOUniversalBinary::getObjectForArch(
153     Triple::ArchType Arch, std::unique_ptr<ObjectFile> &Result) const {
154   MachO::CPUType CTM;
155   if (!getCTMForArch(Arch, CTM))
156     return object_error::arch_not_found;
157   for (object_iterator I = begin_objects(), E = end_objects(); I != E; ++I) {
158     if (I->getCPUType() == static_cast<uint32_t>(CTM))
159       return I->getAsObjectFile(Result);
160   }
161   return object_error::arch_not_found;
162 }
163