llvm/lib/ToolDrivers/llvm-lib/LibDriver.cpp

   1 //===- LibDriver.cpp - lib.exe-compatible driver --------------------------===//
   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 an interface to a lib.exe-compatible driver that also understands
  10 // bitcode files. Used by llvm-lib and lld-link /lib.
  11 //
  12 //===----------------------------------------------------------------------===//
  13
  14 #include "llvm/ToolDrivers/llvm-lib/LibDriver.h"
  15 #include "llvm/ADT/STLExtras.h"
  16 #include "llvm/ADT/StringSet.h"
  17 #include "llvm/BinaryFormat/COFF.h"
  18 #include "llvm/BinaryFormat/Magic.h"
  19 #include "llvm/Bitcode/BitcodeReader.h"
  20 #include "llvm/Object/ArchiveWriter.h"
  21 #include "llvm/Object/COFF.h"
  22 #include "llvm/Object/WindowsMachineFlag.h"
  23 #include "llvm/Option/Arg.h"
  24 #include "llvm/Option/ArgList.h"
  25 #include "llvm/Option/Option.h"
  26 #include "llvm/Support/CommandLine.h"
  27 #include "llvm/Support/Path.h"
  28 #include "llvm/Support/Process.h"
  29 #include "llvm/Support/StringSaver.h"
  30 #include "llvm/Support/raw_ostream.h"
  31
  32 using namespace llvm;
  33
  34 namespace {
  35
  36 enum {
  37   OPT_INVALID = 0,
  38 #define OPTION(_1, _2, ID, _4, _5, _6, _7, _8, _9, _10, _11, _12) OPT_##ID,
  39 #include "Options.inc"
  40 #undef OPTION
  41 };
  42
  43 #define PREFIX(NAME, VALUE) const char *const NAME[] = VALUE;
  44 #include "Options.inc"
  45 #undef PREFIX
  46
  47 static const opt::OptTable::Info InfoTable[] = {
  48 #define OPTION(X1, X2, ID, KIND, GROUP, ALIAS, X7, X8, X9, X10, X11, X12)      \
  49   {X1, X2, X10,         X11,         OPT_##ID, opt::Option::KIND##Class,       \
  50    X9, X8, OPT_##GROUP, OPT_##ALIAS, X7,       X12},
  51 #include "Options.inc"
  52 #undef OPTION
  53 };
  54
  55 class LibOptTable : public opt::OptTable {
  56 public:
  57   LibOptTable() : OptTable(InfoTable, true) {}
  58 };
  59
  60 }
  61
  62 static std::string getDefaultOutputPath(const NewArchiveMember &FirstMember) {
  63   SmallString<128> Val = StringRef(FirstMember.Buf->getBufferIdentifier());
  64   sys::path::replace_extension(Val, ".lib");
  65   return std::string(Val.str());
  66 }
  67
  68 static std::vector<StringRef> getSearchPaths(opt::InputArgList *Args,
  69                                              StringSaver &Saver) {
  70   std::vector<StringRef> Ret;
  71   // Add current directory as first item of the search path.
  72   Ret.push_back("");
  73
  74   // Add /libpath flags.
  75   for (auto *Arg : Args->filtered(OPT_libpath))
  76     Ret.push_back(Arg->getValue());
  77
  78   // Add $LIB.
  79   Optional<std::string> EnvOpt = sys::Process::GetEnv("LIB");
  80   if (!EnvOpt.hasValue())
  81     return Ret;
  82   StringRef Env = Saver.save(*EnvOpt);
  83   while (!Env.empty()) {
  84     StringRef Path;
  85     std::tie(Path, Env) = Env.split(';');
  86     Ret.push_back(Path);
  87   }
  88   return Ret;
  89 }
  90
  91 static std::string findInputFile(StringRef File, ArrayRef<StringRef> Paths) {
  92   for (StringRef Dir : Paths) {
  93     SmallString<128> Path = Dir;
  94     sys::path::append(Path, File);
  95     if (sys::fs::exists(Path))
  96       return std::string(Path);
  97   }
  98   return "";
  99 }
 100
 101 static void fatalOpenError(llvm::Error E, Twine File) {
 102   if (!E)
 103     return;
 104   handleAllErrors(std::move(E), [&](const llvm::ErrorInfoBase &EIB) {
 105     llvm::errs() << "error opening '" << File << "': " << EIB.message() << '\n';
 106     exit(1);
 107   });
 108 }
 109
 110 static void doList(opt::InputArgList& Args) {
 111   // lib.exe prints the contents of the first archive file.
 112   std::unique_ptr<MemoryBuffer> B;
 113   for (auto *Arg : Args.filtered(OPT_INPUT)) {
 114     // Create or open the archive object.
 115     ErrorOr<std::unique_ptr<MemoryBuffer>> MaybeBuf = MemoryBuffer::getFile(
 116         Arg->getValue(), /*IsText=*/false, /*RequiresNullTerminator=*/false);
 117     fatalOpenError(errorCodeToError(MaybeBuf.getError()), Arg->getValue());
 118
 119     if (identify_magic(MaybeBuf.get()->getBuffer()) == file_magic::archive) {
 120       B = std::move(MaybeBuf.get());
 121       break;
 122     }
 123   }
 124
 125   // lib.exe doesn't print an error if no .lib files are passed.
 126   if (!B)
 127     return;
 128
 129   Error Err = Error::success();
 130   object::Archive Archive(B.get()->getMemBufferRef(), Err);
 131   fatalOpenError(std::move(Err), B->getBufferIdentifier());
 132
 133   for (auto &C : Archive.children(Err)) {
 134     Expected<StringRef> NameOrErr = C.getName();
 135     fatalOpenError(NameOrErr.takeError(), B->getBufferIdentifier());
 136     StringRef Name = NameOrErr.get();
 137     llvm::outs() << Name << '\n';
 138   }
 139   fatalOpenError(std::move(Err), B->getBufferIdentifier());
 140 }
 141
 142 static Expected<COFF::MachineTypes> getCOFFFileMachine(MemoryBufferRef MB) {
 143   std::error_code EC;
 144   auto Obj = object::COFFObjectFile::create(MB);
 145   if (!Obj)
 146     return Obj.takeError();
 147
 148   uint16_t Machine = (*Obj)->getMachine();
 149   if (Machine != COFF::IMAGE_FILE_MACHINE_I386 &&
 150       Machine != COFF::IMAGE_FILE_MACHINE_AMD64 &&
 151       Machine != COFF::IMAGE_FILE_MACHINE_ARMNT &&
 152       Machine != COFF::IMAGE_FILE_MACHINE_ARM64) {
 153     return createStringError(inconvertibleErrorCode(),
 154                              "unknown machine: " + std::to_string(Machine));
 155   }
 156
 157   return static_cast<COFF::MachineTypes>(Machine);
 158 }
 159
 160 static Expected<COFF::MachineTypes> getBitcodeFileMachine(MemoryBufferRef MB) {
 161   Expected<std::string> TripleStr = getBitcodeTargetTriple(MB);
 162   if (!TripleStr)
 163     return TripleStr.takeError();
 164
 165   switch (Triple(*TripleStr).getArch()) {
 166   case Triple::x86:
 167     return COFF::IMAGE_FILE_MACHINE_I386;
 168   case Triple::x86_64:
 169     return COFF::IMAGE_FILE_MACHINE_AMD64;
 170   case Triple::arm:
 171     return COFF::IMAGE_FILE_MACHINE_ARMNT;
 172   case Triple::aarch64:
 173     return COFF::IMAGE_FILE_MACHINE_ARM64;
 174   default:
 175     return createStringError(inconvertibleErrorCode(),
 176                              "unknown arch in target triple: " + *TripleStr);
 177   }
 178 }
 179
 180 static void appendFile(std::vector<NewArchiveMember> &Members,
 181                        COFF::MachineTypes &LibMachine,
 182                        std::string &LibMachineSource, MemoryBufferRef MB) {
 183   file_magic Magic = identify_magic(MB.getBuffer());
 184
 185   if (Magic != file_magic::coff_object && Magic != file_magic::bitcode &&
 186       Magic != file_magic::archive && Magic != file_magic::windows_resource &&
 187       Magic != file_magic::coff_import_library) {
 188     llvm::errs() << MB.getBufferIdentifier()
 189                  << ": not a COFF object, bitcode, archive, import library or "
 190                     "resource file\n";
 191     exit(1);
 192   }
 193
 194   // If a user attempts to add an archive to another archive, llvm-lib doesn't
 195   // handle the first archive file as a single file. Instead, it extracts all
 196   // members from the archive and add them to the second archive. This behavior
 197   // is for compatibility with Microsoft's lib command.
 198   if (Magic == file_magic::archive) {
 199     Error Err = Error::success();
 200     object::Archive Archive(MB, Err);
 201     fatalOpenError(std::move(Err), MB.getBufferIdentifier());
 202
 203     for (auto &C : Archive.children(Err)) {
 204       Expected<MemoryBufferRef> ChildMB = C.getMemoryBufferRef();
 205       if (!ChildMB) {
 206         handleAllErrors(ChildMB.takeError(), [&](const ErrorInfoBase &EIB) {
 207           llvm::errs() << MB.getBufferIdentifier() << ": " << EIB.message()
 208                        << "\n";
 209         });
 210         exit(1);
 211       }
 212
 213       appendFile(Members, LibMachine, LibMachineSource, *ChildMB);
 214     }
 215
 216     fatalOpenError(std::move(Err), MB.getBufferIdentifier());
 217     return;
 218   }
 219
 220   // Check that all input files have the same machine type.
 221   // Mixing normal objects and LTO bitcode files is fine as long as they
 222   // have the same machine type.
 223   // Doing this here duplicates the header parsing work that writeArchive()
 224   // below does, but it's not a lot of work and it's a bit awkward to do
 225   // in writeArchive() which needs to support many tools, can't assume the
 226   // input is COFF, and doesn't have a good way to report errors.
 227   if (Magic == file_magic::coff_object || Magic == file_magic::bitcode) {
 228     Expected<COFF::MachineTypes> MaybeFileMachine =
 229         (Magic == file_magic::coff_object) ? getCOFFFileMachine(MB)
 230                                            : getBitcodeFileMachine(MB);
 231     if (!MaybeFileMachine) {
 232       handleAllErrors(MaybeFileMachine.takeError(), [&](const ErrorInfoBase &EIB) {
 233         llvm::errs() << MB.getBufferIdentifier() << ": " << EIB.message()
 234                      << "\n";
 235       });
 236       exit(1);
 237     }
 238     COFF::MachineTypes FileMachine = *MaybeFileMachine;
 239
 240     // FIXME: Once lld-link rejects multiple resource .obj files:
 241     // Call convertResToCOFF() on .res files and add the resulting
 242     // COFF file to the .lib output instead of adding the .res file, and remove
 243     // this check. See PR42180.
 244     if (FileMachine != COFF::IMAGE_FILE_MACHINE_UNKNOWN) {
 245       if (LibMachine == COFF::IMAGE_FILE_MACHINE_UNKNOWN) {
 246         LibMachine = FileMachine;
 247         LibMachineSource =
 248             (" (inferred from earlier file '" + MB.getBufferIdentifier() + "')")
 249                 .str();
 250       } else if (LibMachine != FileMachine) {
 251         llvm::errs() << MB.getBufferIdentifier() << ": file machine type "
 252                      << machineToStr(FileMachine)
 253                      << " conflicts with library machine type "
 254                      << machineToStr(LibMachine) << LibMachineSource << '\n';
 255         exit(1);
 256       }
 257     }
 258   }
 259
 260   Members.emplace_back(MB);
 261 }
 262
 263 int llvm::libDriverMain(ArrayRef<const char *> ArgsArr) {
 264   BumpPtrAllocator Alloc;
 265   StringSaver Saver(Alloc);
 266
 267   // Parse command line arguments.
 268   SmallVector<const char *, 20> NewArgs(ArgsArr.begin(), ArgsArr.end());
 269   cl::ExpandResponseFiles(Saver, cl::TokenizeWindowsCommandLine, NewArgs);
 270   ArgsArr = NewArgs;
 271
 272   LibOptTable Table;
 273   unsigned MissingIndex;
 274   unsigned MissingCount;
 275   opt::InputArgList Args =
 276       Table.ParseArgs(ArgsArr.slice(1), MissingIndex, MissingCount);
 277   if (MissingCount) {
 278     llvm::errs() << "missing arg value for \""
 279                  << Args.getArgString(MissingIndex) << "\", expected "
 280                  << MissingCount
 281                  << (MissingCount == 1 ? " argument.\n" : " arguments.\n");
 282     return 1;
 283   }
 284   for (auto *Arg : Args.filtered(OPT_UNKNOWN))
 285     llvm::errs() << "ignoring unknown argument: " << Arg->getAsString(Args)
 286                  << "\n";
 287
 288   // Handle /help
 289   if (Args.hasArg(OPT_help)) {
 290     Table.printHelp(outs(), "llvm-lib [options] file...", "LLVM Lib");
 291     return 0;
 292   }
 293
 294   // If no input files and not told otherwise, silently do nothing to match
 295   // lib.exe
 296   if (!Args.hasArgNoClaim(OPT_INPUT) && !Args.hasArg(OPT_llvmlibempty))
 297     return 0;
 298
 299   if (Args.hasArg(OPT_lst)) {
 300     doList(Args);
 301     return 0;
 302   }
 303
 304   std::vector<StringRef> SearchPaths = getSearchPaths(&Args, Saver);
 305
 306   COFF::MachineTypes LibMachine = COFF::IMAGE_FILE_MACHINE_UNKNOWN;
 307   std::string LibMachineSource;
 308   if (auto *Arg = Args.getLastArg(OPT_machine)) {
 309     LibMachine = getMachineType(Arg->getValue());
 310     if (LibMachine == COFF::IMAGE_FILE_MACHINE_UNKNOWN) {
 311       llvm::errs() << "unknown /machine: arg " << Arg->getValue() << '\n';
 312       return 1;
 313     }
 314     LibMachineSource =
 315         std::string(" (from '/machine:") + Arg->getValue() + "' flag)";
 316   }
 317
 318   std::vector<std::unique_ptr<MemoryBuffer>> MBs;
 319   StringSet<> Seen;
 320   std::vector<NewArchiveMember> Members;
 321
 322   // Create a NewArchiveMember for each input file.
 323   for (auto *Arg : Args.filtered(OPT_INPUT)) {
 324     // Find a file
 325     std::string Path = findInputFile(Arg->getValue(), SearchPaths);
 326     if (Path.empty()) {
 327       llvm::errs() << Arg->getValue() << ": no such file or directory\n";
 328       return 1;
 329     }
 330
 331     // Input files are uniquified by pathname. If you specify the exact same
 332     // path more than once, all but the first one are ignored.
 333     //
 334     // Note that there's a loophole in the rule; you can prepend `.\` or
 335     // something like that to a path to make it look different, and they are
 336     // handled as if they were different files. This behavior is compatible with
 337     // Microsoft lib.exe.
 338     if (!Seen.insert(Path).second)
 339       continue;
 340
 341     // Open a file.
 342     ErrorOr<std::unique_ptr<MemoryBuffer>> MOrErr = MemoryBuffer::getFile(
 343         Path, /*IsText=*/false, /*RequiresNullTerminator=*/false);
 344     fatalOpenError(errorCodeToError(MOrErr.getError()), Path);
 345     MemoryBufferRef MBRef = (*MOrErr)->getMemBufferRef();
 346
 347     // Append a file.
 348     appendFile(Members, LibMachine, LibMachineSource, MBRef);
 349
 350     // Take the ownership of the file buffer to keep the file open.
 351     MBs.push_back(std::move(*MOrErr));
 352   }
 353
 354   // Create an archive file.
 355   std::string OutputPath;
 356   if (auto *Arg = Args.getLastArg(OPT_out)) {
 357     OutputPath = Arg->getValue();
 358   } else if (!Members.empty()) {
 359     OutputPath = getDefaultOutputPath(Members[0]);
 360   } else {
 361     llvm::errs() << "no output path given, and cannot infer with no inputs\n";
 362     return 1;
 363   }
 364   // llvm-lib uses relative paths for both regular and thin archives, unlike
 365   // standard GNU ar, which only uses relative paths for thin archives and
 366   // basenames for regular archives.
 367   for (NewArchiveMember &Member : Members) {
 368     if (sys::path::is_relative(Member.MemberName)) {
 369       Expected<std::string> PathOrErr =
 370           computeArchiveRelativePath(OutputPath, Member.MemberName);
 371       if (PathOrErr)
 372         Member.MemberName = Saver.save(*PathOrErr);
 373     }
 374   }
 375
 376   if (Error E =
 377           writeArchive(OutputPath, Members,
 378                        /*WriteSymtab=*/true, object::Archive::K_GNU,
 379                        /*Deterministic*/ true, Args.hasArg(OPT_llvmlibthin))) {
 380     handleAllErrors(std::move(E), [&](const ErrorInfoBase &EI) {
 381       llvm::errs() << OutputPath << ": " << EI.message() << "\n";
 382     });
 383     return 1;
 384   }
 385
 386   return 0;
 387 }