llvm/lib/Object/MachOUniversal.cpp

   1 //===- MachOUniversal.cpp - Mach-O universal binary -------------*- C++ -*-===//
   2 //
   3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
   4 // See https://llvm.org/LICENSE.txt for license information.
   5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
   6 //
   7 //===----------------------------------------------------------------------===//
   8 //
   9 // This file defines the MachOUniversalBinary class.
  10 //
  11 //===----------------------------------------------------------------------===//
  12
  13 #include "llvm/Object/MachOUniversal.h"
  14 #include "llvm/Object/Archive.h"
  15 #include "llvm/Object/IRObjectFile.h"
  16 #include "llvm/Object/MachO.h"
  17 #include "llvm/Object/ObjectFile.h"
  18 #include "llvm/Support/ErrorHandling.h"
  19 #include "llvm/Support/SwapByteOrder.h"
  20 #include "llvm/Support/type_traits.h"
  21
  22 using namespace llvm;
  23 using namespace object;
  24
  25 static Error
  26 malformedError(Twine Msg) {
  27   std::string StringMsg = "truncated or malformed fat file (" + Msg.str() + ")";
  28   return make_error<GenericBinaryError>(std::move(StringMsg),
  29                                         object_error::parse_failed);
  30 }
  31
  32 template<typename T>
  33 static T getUniversalBinaryStruct(const char *Ptr) {
  34   T Res;
  35   memcpy(&Res, Ptr, sizeof(T));
  36   // Universal binary headers have big-endian byte order.
  37   if (sys::IsLittleEndianHost)
  38     swapStruct(Res);
  39   return Res;
  40 }
  41
  42 MachOUniversalBinary::ObjectForArch::ObjectForArch(
  43     const MachOUniversalBinary *Parent, uint32_t Index)
  44     : Parent(Parent), Index(Index) {
  45   // The iterators use Parent as a nullptr and an Index+1 == NumberOfObjects.
  46   if (!Parent || Index >= Parent->getNumberOfObjects()) {
  47     clear();
  48   } else {
  49     // Parse object header.
  50     StringRef ParentData = Parent->getData();
  51     if (Parent->getMagic() == MachO::FAT_MAGIC) {
  52       const char *HeaderPos = ParentData.begin() + sizeof(MachO::fat_header) +
  53                               Index * sizeof(MachO::fat_arch);
  54       Header = getUniversalBinaryStruct<MachO::fat_arch>(HeaderPos);
  55     } else { // Parent->getMagic() == MachO::FAT_MAGIC_64
  56       const char *HeaderPos = ParentData.begin() + sizeof(MachO::fat_header) +
  57                               Index * sizeof(MachO::fat_arch_64);
  58       Header64 = getUniversalBinaryStruct<MachO::fat_arch_64>(HeaderPos);
  59     }
  60   }
  61 }
  62
  63 Expected<std::unique_ptr<MachOObjectFile>>
  64 MachOUniversalBinary::ObjectForArch::getAsObjectFile() const {
  65   if (!Parent)
  66     report_fatal_error("MachOUniversalBinary::ObjectForArch::getAsObjectFile() "
  67                        "called when Parent is a nullptr");
  68
  69   StringRef ParentData = Parent->getData();
  70   StringRef ObjectData;
  71   uint32_t cputype;
  72   if (Parent->getMagic() == MachO::FAT_MAGIC) {
  73     ObjectData = ParentData.substr(Header.offset, Header.size);
  74     cputype = Header.cputype;
  75   } else { // Parent->getMagic() == MachO::FAT_MAGIC_64
  76     ObjectData = ParentData.substr(Header64.offset, Header64.size);
  77     cputype = Header64.cputype;
  78   }
  79   StringRef ObjectName = Parent->getFileName();
  80   MemoryBufferRef ObjBuffer(ObjectData, ObjectName);
  81   return ObjectFile::createMachOObjectFile(ObjBuffer, cputype, Index);
  82 }
  83
  84 Expected<std::unique_ptr<IRObjectFile>>
  85 MachOUniversalBinary::ObjectForArch::getAsIRObject(LLVMContext &Ctx) const {
  86   if (!Parent)
  87     report_fatal_error("MachOUniversalBinary::ObjectForArch::getAsIRObject() "
  88                        "called when Parent is a nullptr");
  89
  90   StringRef ParentData = Parent->getData();
  91   StringRef ObjectData;
  92   if (Parent->getMagic() == MachO::FAT_MAGIC) {
  93     ObjectData = ParentData.substr(Header.offset, Header.size);
  94   } else { // Parent->getMagic() == MachO::FAT_MAGIC_64
  95     ObjectData = ParentData.substr(Header64.offset, Header64.size);
  96   }
  97   StringRef ObjectName = Parent->getFileName();
  98   MemoryBufferRef ObjBuffer(ObjectData, ObjectName);
  99
 100   return IRObjectFile::create(ObjBuffer, Ctx);
 101 }
 102
 103 Expected<std::unique_ptr<Archive>>
 104 MachOUniversalBinary::ObjectForArch::getAsArchive() const {
 105   if (!Parent)
 106     report_fatal_error("MachOUniversalBinary::ObjectForArch::getAsArchive() "
 107                        "called when Parent is a nullptr");
 108
 109   StringRef ParentData = Parent->getData();
 110   StringRef ObjectData;
 111   if (Parent->getMagic() == MachO::FAT_MAGIC)
 112     ObjectData = ParentData.substr(Header.offset, Header.size);
 113   else // Parent->getMagic() == MachO::FAT_MAGIC_64
 114     ObjectData = ParentData.substr(Header64.offset, Header64.size);
 115   StringRef ObjectName = Parent->getFileName();
 116   MemoryBufferRef ObjBuffer(ObjectData, ObjectName);
 117   return Archive::create(ObjBuffer);
 118 }
 119
 120 void MachOUniversalBinary::anchor() { }
 121
 122 Expected<std::unique_ptr<MachOUniversalBinary>>
 123 MachOUniversalBinary::create(MemoryBufferRef Source) {
 124   Error Err = Error::success();
 125   std::unique_ptr<MachOUniversalBinary> Ret(
 126       new MachOUniversalBinary(Source, Err));
 127   if (Err)
 128     return std::move(Err);
 129   return std::move(Ret);
 130 }
 131
 132 MachOUniversalBinary::MachOUniversalBinary(MemoryBufferRef Source, Error &Err)
 133     : Binary(Binary::ID_MachOUniversalBinary, Source), Magic(0),
 134       NumberOfObjects(0) {
 135   ErrorAsOutParameter ErrAsOutParam(&Err);
 136   if (Data.getBufferSize() < sizeof(MachO::fat_header)) {
 137     Err = make_error<GenericBinaryError>("File too small to be a Mach-O "
 138                                          "universal file",
 139                                          object_error::invalid_file_type);
 140     return;
 141   }
 142   // Check for magic value and sufficient header size.
 143   StringRef Buf = getData();
 144   MachO::fat_header H =
 145       getUniversalBinaryStruct<MachO::fat_header>(Buf.begin());
 146   Magic = H.magic;
 147   NumberOfObjects = H.nfat_arch;
 148   if (NumberOfObjects == 0) {
 149     Err = malformedError("contains zero architecture types");
 150     return;
 151   }
 152   uint32_t MinSize = sizeof(MachO::fat_header);
 153   if (Magic == MachO::FAT_MAGIC)
 154     MinSize += sizeof(MachO::fat_arch) * NumberOfObjects;
 155   else if (Magic == MachO::FAT_MAGIC_64)
 156     MinSize += sizeof(MachO::fat_arch_64) * NumberOfObjects;
 157   else {
 158     Err = malformedError("bad magic number");
 159     return;
 160   }
 161   if (Buf.size() < MinSize) {
 162     Err = malformedError("fat_arch" +
 163                          Twine(Magic == MachO::FAT_MAGIC ? "" : "_64") +
 164                          " structs would extend past the end of the file");
 165     return;
 166   }
 167   for (uint32_t i = 0; i < NumberOfObjects; i++) {
 168     ObjectForArch A(this, i);
 169     uint64_t bigSize = A.getOffset();
 170     bigSize += A.getSize();
 171     if (bigSize > Buf.size()) {
 172       Err = malformedError("offset plus size of cputype (" +
 173         Twine(A.getCPUType()) + ") cpusubtype (" +
 174         Twine(A.getCPUSubType() & ~MachO::CPU_SUBTYPE_MASK) +
 175         ") extends past the end of the file");
 176       return;
 177     }
 178
 179     if (A.getAlign() > MaxSectionAlignment) {
 180       Err = malformedError("align (2^" + Twine(A.getAlign()) +
 181                            ") too large for cputype (" + Twine(A.getCPUType()) +
 182                            ") cpusubtype (" +
 183                            Twine(A.getCPUSubType() & ~MachO::CPU_SUBTYPE_MASK) +
 184                            ") (maximum 2^" + Twine(MaxSectionAlignment) + ")");
 185       return;
 186     }
 187     if(A.getOffset() % (1ull << A.getAlign()) != 0){
 188       Err = malformedError("offset: " + Twine(A.getOffset()) +
 189         " for cputype (" + Twine(A.getCPUType()) + ") cpusubtype (" +
 190         Twine(A.getCPUSubType() & ~MachO::CPU_SUBTYPE_MASK) +
 191         ") not aligned on it's alignment (2^" + Twine(A.getAlign()) + ")");
 192       return;
 193     }
 194     if (A.getOffset() < MinSize) {
 195       Err =  malformedError("cputype (" + Twine(A.getCPUType()) + ") "
 196         "cpusubtype (" + Twine(A.getCPUSubType() & ~MachO::CPU_SUBTYPE_MASK) +
 197         ") offset " + Twine(A.getOffset()) + " overlaps universal headers");
 198       return;
 199     }
 200   }
 201   for (uint32_t i = 0; i < NumberOfObjects; i++) {
 202     ObjectForArch A(this, i);
 203     for (uint32_t j = i + 1; j < NumberOfObjects; j++) {
 204       ObjectForArch B(this, j);
 205       if (A.getCPUType() == B.getCPUType() &&
 206           (A.getCPUSubType() & ~MachO::CPU_SUBTYPE_MASK) ==
 207           (B.getCPUSubType() & ~MachO::CPU_SUBTYPE_MASK)) {
 208         Err = malformedError("contains two of the same architecture (cputype "
 209           "(" + Twine(A.getCPUType()) + ") cpusubtype (" +
 210           Twine(A.getCPUSubType() & ~MachO::CPU_SUBTYPE_MASK) + "))");
 211         return;
 212       }
 213       if ((A.getOffset() >= B.getOffset() &&
 214            A.getOffset() < B.getOffset() + B.getSize()) ||
 215           (A.getOffset() + A.getSize() > B.getOffset() &&
 216            A.getOffset() + A.getSize() < B.getOffset() + B.getSize()) ||
 217           (A.getOffset() <= B.getOffset() &&
 218            A.getOffset() + A.getSize() >= B.getOffset() + B.getSize())) {
 219         Err =  malformedError("cputype (" + Twine(A.getCPUType()) + ") "
 220           "cpusubtype (" + Twine(A.getCPUSubType() & ~MachO::CPU_SUBTYPE_MASK) +
 221           ") at offset " + Twine(A.getOffset()) + " with a size of " +
 222           Twine(A.getSize()) + ", overlaps cputype (" + Twine(B.getCPUType()) +
 223           ") cpusubtype (" + Twine(B.getCPUSubType() & ~MachO::CPU_SUBTYPE_MASK)
 224           + ") at offset " + Twine(B.getOffset()) + " with a size of "
 225           + Twine(B.getSize()));
 226         return;
 227       }
 228     }
 229   }
 230   Err = Error::success();
 231 }
 232
 233 Expected<MachOUniversalBinary::ObjectForArch>
 234 MachOUniversalBinary::getObjectForArch(StringRef ArchName) const {
 235   if (Triple(ArchName).getArch() == Triple::ArchType::UnknownArch)
 236     return make_error<GenericBinaryError>("Unknown architecture "
 237                                           "named: " +
 238                                               ArchName,
 239                                           object_error::arch_not_found);
 240   for (const auto &Obj : objects())
 241     if (Obj.getArchFlagName() == ArchName)
 242       return Obj;
 243   return make_error<GenericBinaryError>("fat file does not "
 244                                         "contain " +
 245                                             ArchName,
 246                                         object_error::arch_not_found);
 247 }
 248
 249 Expected<std::unique_ptr<MachOObjectFile>>
 250 MachOUniversalBinary::getMachOObjectForArch(StringRef ArchName) const {
 251   Expected<ObjectForArch> O = getObjectForArch(ArchName);
 252   if (!O)
 253     return O.takeError();
 254   return O->getAsObjectFile();
 255 }
 256
 257 Expected<std::unique_ptr<IRObjectFile>>
 258 MachOUniversalBinary::getIRObjectForArch(StringRef ArchName,
 259                                          LLVMContext &Ctx) const {
 260   Expected<ObjectForArch> O = getObjectForArch(ArchName);
 261   if (!O)
 262     return O.takeError();
 263   return O->getAsIRObject(Ctx);
 264 }
 265
 266 Expected<std::unique_ptr<Archive>>
 267 MachOUniversalBinary::getArchiveForArch(StringRef ArchName) const {
 268   Expected<ObjectForArch> O = getObjectForArch(ArchName);
 269   if (!O)
 270     return O.takeError();
 271   return O->getAsArchive();
 272 }