1 //===- MachOUniversalWriter.cpp - MachO universal binary writer---*- 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 // Defines the Slice class and writeUniversalBinary function for writing a MachO 10 // universal binary file. 11 // 12 //===----------------------------------------------------------------------===// 13 14 #include "llvm/Object/MachOUniversalWriter.h" 15 #include "llvm/ADT/STLExtras.h" 16 #include "llvm/ADT/SmallVector.h" 17 #include "llvm/Object/Archive.h" 18 #include "llvm/Object/Binary.h" 19 #include "llvm/Object/IRObjectFile.h" 20 #include "llvm/Object/MachO.h" 21 #include "llvm/Object/MachOUniversal.h" 22 #include "llvm/Support/Casting.h" 23 #include "llvm/Support/ErrorHandling.h" 24 #include "llvm/Support/FileSystem.h" 25 #include "llvm/Support/MathExtras.h" 26 #include "llvm/Support/MemoryBufferRef.h" 27 #include "llvm/Support/SwapByteOrder.h" 28 #include "llvm/Support/raw_ostream.h" 29 #include "llvm/TargetParser/Triple.h" 30 31 using namespace llvm; 32 using namespace object; 33 34 // For compatibility with cctools lipo, a file's alignment is calculated as the 35 // minimum aligment of all segments. For object files, the file's alignment is 36 // the maximum alignment of its sections. 37 static uint32_t calculateFileAlignment(const MachOObjectFile &O) { 38 uint32_t P2CurrentAlignment; 39 uint32_t P2MinAlignment = MachOUniversalBinary::MaxSectionAlignment; 40 const bool Is64Bit = O.is64Bit(); 41 42 for (const auto &LC : O.load_commands()) { 43 if (LC.C.cmd != (Is64Bit ? MachO::LC_SEGMENT_64 : MachO::LC_SEGMENT)) 44 continue; 45 if (O.getHeader().filetype == MachO::MH_OBJECT) { 46 unsigned NumberOfSections = 47 (Is64Bit ? O.getSegment64LoadCommand(LC).nsects 48 : O.getSegmentLoadCommand(LC).nsects); 49 P2CurrentAlignment = NumberOfSections ? 2 : P2MinAlignment; 50 for (unsigned SI = 0; SI < NumberOfSections; ++SI) { 51 P2CurrentAlignment = std::max(P2CurrentAlignment, 52 (Is64Bit ? O.getSection64(LC, SI).align 53 : O.getSection(LC, SI).align)); 54 } 55 } else { 56 P2CurrentAlignment = 57 llvm::countr_zero(Is64Bit ? O.getSegment64LoadCommand(LC).vmaddr 58 : O.getSegmentLoadCommand(LC).vmaddr); 59 } 60 P2MinAlignment = std::min(P2MinAlignment, P2CurrentAlignment); 61 } 62 // return a value >= 4 byte aligned, and less than MachO MaxSectionAlignment 63 return std::max( 64 static_cast<uint32_t>(2), 65 std::min(P2MinAlignment, static_cast<uint32_t>( 66 MachOUniversalBinary::MaxSectionAlignment))); 67 } 68 69 static uint32_t calculateAlignment(const MachOObjectFile &ObjectFile) { 70 switch (ObjectFile.getHeader().cputype) { 71 case MachO::CPU_TYPE_I386: 72 case MachO::CPU_TYPE_X86_64: 73 case MachO::CPU_TYPE_POWERPC: 74 case MachO::CPU_TYPE_POWERPC64: 75 return 12; // log2 value of page size(4k) for x86 and PPC 76 case MachO::CPU_TYPE_ARM: 77 case MachO::CPU_TYPE_ARM64: 78 case MachO::CPU_TYPE_ARM64_32: 79 return 14; // log2 value of page size(16k) for Darwin ARM 80 default: 81 return calculateFileAlignment(ObjectFile); 82 } 83 } 84 85 Slice::Slice(const Archive &A, uint32_t CPUType, uint32_t CPUSubType, 86 std::string ArchName, uint32_t Align) 87 : B(&A), CPUType(CPUType), CPUSubType(CPUSubType), 88 ArchName(std::move(ArchName)), P2Alignment(Align) {} 89 90 Slice::Slice(const MachOObjectFile &O, uint32_t Align) 91 : B(&O), CPUType(O.getHeader().cputype), 92 CPUSubType(O.getHeader().cpusubtype), 93 ArchName(std::string(O.getArchTriple().getArchName())), 94 P2Alignment(Align) {} 95 96 Slice::Slice(const IRObjectFile &IRO, uint32_t CPUType, uint32_t CPUSubType, 97 std::string ArchName, uint32_t Align) 98 : B(&IRO), CPUType(CPUType), CPUSubType(CPUSubType), 99 ArchName(std::move(ArchName)), P2Alignment(Align) {} 100 101 Slice::Slice(const MachOObjectFile &O) : Slice(O, calculateAlignment(O)) {} 102 103 using MachoCPUTy = std::pair<unsigned, unsigned>; 104 105 static Expected<MachoCPUTy> getMachoCPUFromTriple(Triple TT) { 106 auto CPU = std::make_pair(MachO::getCPUType(TT), MachO::getCPUSubType(TT)); 107 if (!CPU.first) { 108 return CPU.first.takeError(); 109 } 110 if (!CPU.second) { 111 return CPU.second.takeError(); 112 } 113 return std::make_pair(*CPU.first, *CPU.second); 114 } 115 116 static Expected<MachoCPUTy> getMachoCPUFromTriple(StringRef TT) { 117 return getMachoCPUFromTriple(Triple{TT}); 118 } 119 120 Expected<Slice> Slice::create(const Archive &A, LLVMContext *LLVMCtx) { 121 Error Err = Error::success(); 122 std::unique_ptr<MachOObjectFile> MFO = nullptr; 123 std::unique_ptr<IRObjectFile> IRFO = nullptr; 124 for (const Archive::Child &Child : A.children(Err)) { 125 Expected<std::unique_ptr<Binary>> ChildOrErr = Child.getAsBinary(LLVMCtx); 126 if (!ChildOrErr) 127 return createFileError(A.getFileName(), ChildOrErr.takeError()); 128 Binary *Bin = ChildOrErr.get().get(); 129 if (Bin->isMachOUniversalBinary()) 130 return createStringError(std::errc::invalid_argument, 131 ("archive member " + Bin->getFileName() + 132 " is a fat file (not allowed in an archive)") 133 .str() 134 .c_str()); 135 if (Bin->isMachO()) { 136 MachOObjectFile *O = cast<MachOObjectFile>(Bin); 137 if (IRFO) { 138 return createStringError( 139 std::errc::invalid_argument, 140 "archive member %s is a MachO, while previous archive member " 141 "%s was an IR LLVM object", 142 O->getFileName().str().c_str(), IRFO->getFileName().str().c_str()); 143 } 144 if (MFO && 145 std::tie(MFO->getHeader().cputype, MFO->getHeader().cpusubtype) != 146 std::tie(O->getHeader().cputype, O->getHeader().cpusubtype)) { 147 return createStringError( 148 std::errc::invalid_argument, 149 ("archive member " + O->getFileName() + " cputype (" + 150 Twine(O->getHeader().cputype) + ") and cpusubtype(" + 151 Twine(O->getHeader().cpusubtype) + 152 ") does not match previous archive members cputype (" + 153 Twine(MFO->getHeader().cputype) + ") and cpusubtype(" + 154 Twine(MFO->getHeader().cpusubtype) + 155 ") (all members must match) " + MFO->getFileName()) 156 .str() 157 .c_str()); 158 } 159 if (!MFO) { 160 ChildOrErr.get().release(); 161 MFO.reset(O); 162 } 163 } else if (Bin->isIR()) { 164 IRObjectFile *O = cast<IRObjectFile>(Bin); 165 if (MFO) { 166 return createStringError(std::errc::invalid_argument, 167 "archive member '%s' is an LLVM IR object, " 168 "while previous archive member " 169 "'%s' was a MachO", 170 O->getFileName().str().c_str(), 171 MFO->getFileName().str().c_str()); 172 } 173 if (IRFO) { 174 Expected<MachoCPUTy> CPUO = getMachoCPUFromTriple(O->getTargetTriple()); 175 Expected<MachoCPUTy> CPUFO = 176 getMachoCPUFromTriple(IRFO->getTargetTriple()); 177 if (!CPUO) 178 return CPUO.takeError(); 179 if (!CPUFO) 180 return CPUFO.takeError(); 181 if (*CPUO != *CPUFO) { 182 return createStringError( 183 std::errc::invalid_argument, 184 ("archive member " + O->getFileName() + " cputype (" + 185 Twine(CPUO->first) + ") and cpusubtype(" + Twine(CPUO->second) + 186 ") does not match previous archive members cputype (" + 187 Twine(CPUFO->first) + ") and cpusubtype(" + 188 Twine(CPUFO->second) + ") (all members must match) " + 189 IRFO->getFileName()) 190 .str() 191 .c_str()); 192 } 193 } else { 194 ChildOrErr.get().release(); 195 IRFO.reset(O); 196 } 197 } else 198 return createStringError(std::errc::invalid_argument, 199 ("archive member " + Bin->getFileName() + 200 " is neither a MachO file or an LLVM IR file " 201 "(not allowed in an archive)") 202 .str() 203 .c_str()); 204 } 205 if (Err) 206 return createFileError(A.getFileName(), std::move(Err)); 207 if (!MFO && !IRFO) 208 return createStringError( 209 std::errc::invalid_argument, 210 ("empty archive with no architecture specification: " + 211 A.getFileName() + " (can't determine architecture for it)") 212 .str() 213 .c_str()); 214 215 if (MFO) { 216 Slice ArchiveSlice(*(MFO), MFO->is64Bit() ? 3 : 2); 217 ArchiveSlice.B = &A; 218 return ArchiveSlice; 219 } 220 221 // For IR objects 222 Expected<Slice> ArchiveSliceOrErr = Slice::create(*IRFO, 0); 223 if (!ArchiveSliceOrErr) 224 return createFileError(A.getFileName(), ArchiveSliceOrErr.takeError()); 225 auto &ArchiveSlice = ArchiveSliceOrErr.get(); 226 ArchiveSlice.B = &A; 227 return std::move(ArchiveSlice); 228 } 229 230 Expected<Slice> Slice::create(const IRObjectFile &IRO, uint32_t Align) { 231 Expected<MachoCPUTy> CPUOrErr = getMachoCPUFromTriple(IRO.getTargetTriple()); 232 if (!CPUOrErr) 233 return CPUOrErr.takeError(); 234 unsigned CPUType, CPUSubType; 235 std::tie(CPUType, CPUSubType) = CPUOrErr.get(); 236 // We don't directly use the architecture name of the target triple T, as, 237 // for instance, thumb is treated as ARM by the MachOUniversal object. 238 std::string ArchName( 239 MachOObjectFile::getArchTriple(CPUType, CPUSubType).getArchName()); 240 return Slice{IRO, CPUType, CPUSubType, std::move(ArchName), Align}; 241 } 242 243 static Expected<SmallVector<MachO::fat_arch, 2>> 244 buildFatArchList(ArrayRef<Slice> Slices) { 245 SmallVector<MachO::fat_arch, 2> FatArchList; 246 uint64_t Offset = 247 sizeof(MachO::fat_header) + Slices.size() * sizeof(MachO::fat_arch); 248 249 for (const auto &S : Slices) { 250 Offset = alignTo(Offset, 1ull << S.getP2Alignment()); 251 if (Offset > UINT32_MAX) 252 return createStringError( 253 std::errc::invalid_argument, 254 ("fat file too large to be created because the offset " 255 "field in struct fat_arch is only 32-bits and the offset " + 256 Twine(Offset) + " for " + S.getBinary()->getFileName() + 257 " for architecture " + S.getArchString() + "exceeds that.") 258 .str() 259 .c_str()); 260 261 MachO::fat_arch FatArch; 262 FatArch.cputype = S.getCPUType(); 263 FatArch.cpusubtype = S.getCPUSubType(); 264 FatArch.offset = Offset; 265 FatArch.size = S.getBinary()->getMemoryBufferRef().getBufferSize(); 266 FatArch.align = S.getP2Alignment(); 267 Offset += FatArch.size; 268 FatArchList.push_back(FatArch); 269 } 270 return FatArchList; 271 } 272 273 Error object::writeUniversalBinaryToStream(ArrayRef<Slice> Slices, 274 raw_ostream &Out) { 275 MachO::fat_header FatHeader; 276 FatHeader.magic = MachO::FAT_MAGIC; 277 FatHeader.nfat_arch = Slices.size(); 278 279 Expected<SmallVector<MachO::fat_arch, 2>> FatArchListOrErr = 280 buildFatArchList(Slices); 281 if (!FatArchListOrErr) 282 return FatArchListOrErr.takeError(); 283 SmallVector<MachO::fat_arch, 2> FatArchList = *FatArchListOrErr; 284 285 if (sys::IsLittleEndianHost) 286 MachO::swapStruct(FatHeader); 287 Out.write(reinterpret_cast<const char *>(&FatHeader), 288 sizeof(MachO::fat_header)); 289 290 if (sys::IsLittleEndianHost) 291 for (MachO::fat_arch &FA : FatArchList) 292 MachO::swapStruct(FA); 293 Out.write(reinterpret_cast<const char *>(FatArchList.data()), 294 sizeof(MachO::fat_arch) * FatArchList.size()); 295 296 if (sys::IsLittleEndianHost) 297 for (MachO::fat_arch &FA : FatArchList) 298 MachO::swapStruct(FA); 299 300 size_t Offset = 301 sizeof(MachO::fat_header) + sizeof(MachO::fat_arch) * FatArchList.size(); 302 for (size_t Index = 0, Size = Slices.size(); Index < Size; ++Index) { 303 MemoryBufferRef BufferRef = Slices[Index].getBinary()->getMemoryBufferRef(); 304 assert((Offset <= FatArchList[Index].offset) && "Incorrect slice offset"); 305 Out.write_zeros(FatArchList[Index].offset - Offset); 306 Out.write(BufferRef.getBufferStart(), BufferRef.getBufferSize()); 307 Offset = FatArchList[Index].offset + BufferRef.getBufferSize(); 308 } 309 310 Out.flush(); 311 return Error::success(); 312 } 313 314 Error object::writeUniversalBinary(ArrayRef<Slice> Slices, 315 StringRef OutputFileName) { 316 const bool IsExecutable = any_of(Slices, [](Slice S) { 317 return sys::fs::can_execute(S.getBinary()->getFileName()); 318 }); 319 unsigned Mode = sys::fs::all_read | sys::fs::all_write; 320 if (IsExecutable) 321 Mode |= sys::fs::all_exe; 322 Expected<sys::fs::TempFile> Temp = sys::fs::TempFile::create( 323 OutputFileName + ".temp-universal-%%%%%%", Mode); 324 if (!Temp) 325 return Temp.takeError(); 326 raw_fd_ostream Out(Temp->FD, false); 327 if (Error E = writeUniversalBinaryToStream(Slices, Out)) { 328 if (Error DiscardError = Temp->discard()) 329 return joinErrors(std::move(E), std::move(DiscardError)); 330 return E; 331 } 332 return Temp->keep(OutputFileName); 333 } 334