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