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/COFFModuleDefinition.h"
  23 #include "llvm/Object/WindowsMachineFlag.h"
  24 #include "llvm/Option/Arg.h"
  25 #include "llvm/Option/ArgList.h"
  26 #include "llvm/Option/OptTable.h"
  27 #include "llvm/Option/Option.h"
  28 #include "llvm/Support/CommandLine.h"
  29 #include "llvm/Support/Path.h"
  30 #include "llvm/Support/Process.h"
  31 #include "llvm/Support/StringSaver.h"
  32 #include "llvm/Support/raw_ostream.h"
  33 #include <optional>
  34
  35 using namespace llvm;
  36 using namespace llvm::object;
  37
  38 namespace {
  39
  40 enum {
  41   OPT_INVALID = 0,
  42 #define OPTION(...) LLVM_MAKE_OPT_ID(__VA_ARGS__),
  43 #include "Options.inc"
  44 #undef OPTION
  45 };
  46
  47 #define PREFIX(NAME, VALUE)                                                    \
  48   static constexpr StringLiteral NAME##_init[] = VALUE;                        \
  49   static constexpr ArrayRef<StringLiteral> NAME(NAME##_init,                   \
  50                                                 std::size(NAME##_init) - 1);
  51 #include "Options.inc"
  52 #undef PREFIX
  53
  54 using namespace llvm::opt;
  55 static constexpr opt::OptTable::Info InfoTable[] = {
  56 #define OPTION(...) LLVM_CONSTRUCT_OPT_INFO(__VA_ARGS__),
  57 #include "Options.inc"
  58 #undef OPTION
  59 };
  60
  61 class LibOptTable : public opt::GenericOptTable {
  62 public:
  63   LibOptTable() : opt::GenericOptTable(InfoTable, true) {}
  64 };
  65 } // namespace
  66
  67 static std::string getDefaultOutputPath(const NewArchiveMember &FirstMember) {
  68   SmallString<128> Val = StringRef(FirstMember.Buf->getBufferIdentifier());
  69   sys::path::replace_extension(Val, ".lib");
  70   return std::string(Val);
  71 }
  72
  73 static std::vector<StringRef> getSearchPaths(opt::InputArgList *Args,
  74                                              StringSaver &Saver) {
  75   std::vector<StringRef> Ret;
  76   // Add current directory as first item of the search path.
  77   Ret.push_back("");
  78
  79   // Add /libpath flags.
  80   for (auto *Arg : Args->filtered(OPT_libpath))
  81     Ret.push_back(Arg->getValue());
  82
  83   // Add $LIB.
  84   std::optional<std::string> EnvOpt = sys::Process::GetEnv("LIB");
  85   if (!EnvOpt)
  86     return Ret;
  87   StringRef Env = Saver.save(*EnvOpt);
  88   while (!Env.empty()) {
  89     StringRef Path;
  90     std::tie(Path, Env) = Env.split(';');
  91     Ret.push_back(Path);
  92   }
  93   return Ret;
  94 }
  95
  96 // Opens a file. Path has to be resolved already. (used for def file)
  97 std::unique_ptr<MemoryBuffer> openFile(const Twine &Path) {
  98   ErrorOr<std::unique_ptr<llvm::MemoryBuffer>> MB = MemoryBuffer::getFile(Path);
  99
 100   if (std::error_code EC = MB.getError()) {
 101     llvm::errs() << "cannot open file " << Path << ": " << EC.message() << "\n";
 102     return nullptr;
 103   }
 104
 105   return std::move(*MB);
 106 }
 107
 108 static std::string findInputFile(StringRef File, ArrayRef<StringRef> Paths) {
 109   for (StringRef Dir : Paths) {
 110     SmallString<128> Path = Dir;
 111     sys::path::append(Path, File);
 112     if (sys::fs::exists(Path))
 113       return std::string(Path);
 114   }
 115   return "";
 116 }
 117
 118 static void fatalOpenError(llvm::Error E, Twine File) {
 119   if (!E)
 120     return;
 121   handleAllErrors(std::move(E), [&](const llvm::ErrorInfoBase &EIB) {
 122     llvm::errs() << "error opening '" << File << "': " << EIB.message() << '\n';
 123     exit(1);
 124   });
 125 }
 126
 127 static void doList(opt::InputArgList &Args) {
 128   // lib.exe prints the contents of the first archive file.
 129   std::unique_ptr<MemoryBuffer> B;
 130   for (auto *Arg : Args.filtered(OPT_INPUT)) {
 131     // Create or open the archive object.
 132     ErrorOr<std::unique_ptr<MemoryBuffer>> MaybeBuf = MemoryBuffer::getFile(
 133         Arg->getValue(), /*IsText=*/false, /*RequiresNullTerminator=*/false);
 134     fatalOpenError(errorCodeToError(MaybeBuf.getError()), Arg->getValue());
 135
 136     if (identify_magic(MaybeBuf.get()->getBuffer()) == file_magic::archive) {
 137       B = std::move(MaybeBuf.get());
 138       break;
 139     }
 140   }
 141
 142   // lib.exe doesn't print an error if no .lib files are passed.
 143   if (!B)
 144     return;
 145
 146   Error Err = Error::success();
 147   object::Archive Archive(B.get()->getMemBufferRef(), Err);
 148   fatalOpenError(std::move(Err), B->getBufferIdentifier());
 149
 150   std::vector<StringRef> Names;
 151   for (auto &C : Archive.children(Err)) {
 152     Expected<StringRef> NameOrErr = C.getName();
 153     fatalOpenError(NameOrErr.takeError(), B->getBufferIdentifier());
 154     Names.push_back(NameOrErr.get());
 155   }
 156   for (auto Name : reverse(Names))
 157     llvm::outs() << Name << '\n';
 158   fatalOpenError(std::move(Err), B->getBufferIdentifier());
 159 }
 160
 161 static Expected<COFF::MachineTypes> getCOFFFileMachine(MemoryBufferRef MB) {
 162   std::error_code EC;
 163   auto Obj = object::COFFObjectFile::create(MB);
 164   if (!Obj)
 165     return Obj.takeError();
 166
 167   uint16_t Machine = (*Obj)->getMachine();
 168   if (Machine != COFF::IMAGE_FILE_MACHINE_I386 &&
 169       Machine != COFF::IMAGE_FILE_MACHINE_AMD64 &&
 170       Machine != COFF::IMAGE_FILE_MACHINE_ARMNT && !COFF::isAnyArm64(Machine)) {
 171     return createStringError(inconvertibleErrorCode(),
 172                              "unknown machine: " + std::to_string(Machine));
 173   }
 174
 175   return static_cast<COFF::MachineTypes>(Machine);
 176 }
 177
 178 static Expected<COFF::MachineTypes> getBitcodeFileMachine(MemoryBufferRef MB) {
 179   Expected<std::string> TripleStr = getBitcodeTargetTriple(MB);
 180   if (!TripleStr)
 181     return TripleStr.takeError();
 182
 183   Triple T(*TripleStr);
 184   switch (T.getArch()) {
 185   case Triple::x86:
 186     return COFF::IMAGE_FILE_MACHINE_I386;
 187   case Triple::x86_64:
 188     return COFF::IMAGE_FILE_MACHINE_AMD64;
 189   case Triple::arm:
 190     return COFF::IMAGE_FILE_MACHINE_ARMNT;
 191   case Triple::aarch64:
 192     return T.isWindowsArm64EC() ? COFF::IMAGE_FILE_MACHINE_ARM64EC
 193                                 : COFF::IMAGE_FILE_MACHINE_ARM64;
 194   default:
 195     return createStringError(inconvertibleErrorCode(),
 196                              "unknown arch in target triple: " + *TripleStr);
 197   }
 198 }
 199
 200 static bool machineMatches(COFF::MachineTypes LibMachine,
 201                            COFF::MachineTypes FileMachine) {
 202   if (LibMachine == FileMachine)
 203     return true;
 204   // ARM64EC mode allows both pure ARM64, ARM64EC and X64 objects to be mixed in
 205   // the archive.
 206   switch (LibMachine) {
 207   case COFF::IMAGE_FILE_MACHINE_ARM64:
 208     return FileMachine == COFF::IMAGE_FILE_MACHINE_ARM64X;
 209   case COFF::IMAGE_FILE_MACHINE_ARM64EC:
 210   case COFF::IMAGE_FILE_MACHINE_ARM64X:
 211     return COFF::isAnyArm64(FileMachine) ||
 212            FileMachine == COFF::IMAGE_FILE_MACHINE_AMD64;
 213   default:
 214     return false;
 215   }
 216 }
 217
 218 static void appendFile(std::vector<NewArchiveMember> &Members,
 219                        COFF::MachineTypes &LibMachine,
 220                        std::string &LibMachineSource, MemoryBufferRef MB) {
 221   file_magic Magic = identify_magic(MB.getBuffer());
 222
 223   if (Magic != file_magic::coff_object && Magic != file_magic::bitcode &&
 224       Magic != file_magic::archive && Magic != file_magic::windows_resource &&
 225       Magic != file_magic::coff_import_library) {
 226     llvm::errs() << MB.getBufferIdentifier()
 227                  << ": not a COFF object, bitcode, archive, import library or "
 228                     "resource file\n";
 229     exit(1);
 230   }
 231
 232   // If a user attempts to add an archive to another archive, llvm-lib doesn't
 233   // handle the first archive file as a single file. Instead, it extracts all
 234   // members from the archive and add them to the second archive. This behavior
 235   // is for compatibility with Microsoft's lib command.
 236   if (Magic == file_magic::archive) {
 237     Error Err = Error::success();
 238     object::Archive Archive(MB, Err);
 239     fatalOpenError(std::move(Err), MB.getBufferIdentifier());
 240
 241     for (auto &C : Archive.children(Err)) {
 242       Expected<MemoryBufferRef> ChildMB = C.getMemoryBufferRef();
 243       if (!ChildMB) {
 244         handleAllErrors(ChildMB.takeError(), [&](const ErrorInfoBase &EIB) {
 245           llvm::errs() << MB.getBufferIdentifier() << ": " << EIB.message()
 246                        << "\n";
 247         });
 248         exit(1);
 249       }
 250
 251       appendFile(Members, LibMachine, LibMachineSource, *ChildMB);
 252     }
 253
 254     fatalOpenError(std::move(Err), MB.getBufferIdentifier());
 255     return;
 256   }
 257
 258   // Check that all input files have the same machine type.
 259   // Mixing normal objects and LTO bitcode files is fine as long as they
 260   // have the same machine type.
 261   // Doing this here duplicates the header parsing work that writeArchive()
 262   // below does, but it's not a lot of work and it's a bit awkward to do
 263   // in writeArchive() which needs to support many tools, can't assume the
 264   // input is COFF, and doesn't have a good way to report errors.
 265   if (Magic == file_magic::coff_object || Magic == file_magic::bitcode) {
 266     Expected<COFF::MachineTypes> MaybeFileMachine =
 267         (Magic == file_magic::coff_object) ? getCOFFFileMachine(MB)
 268                                            : getBitcodeFileMachine(MB);
 269     if (!MaybeFileMachine) {
 270       handleAllErrors(MaybeFileMachine.takeError(),
 271                       [&](const ErrorInfoBase &EIB) {
 272                         llvm::errs() << MB.getBufferIdentifier() << ": "
 273                                      << EIB.message() << "\n";
 274                       });
 275       exit(1);
 276     }
 277     COFF::MachineTypes FileMachine = *MaybeFileMachine;
 278
 279     // FIXME: Once lld-link rejects multiple resource .obj files:
 280     // Call convertResToCOFF() on .res files and add the resulting
 281     // COFF file to the .lib output instead of adding the .res file, and remove
 282     // this check. See PR42180.
 283     if (FileMachine != COFF::IMAGE_FILE_MACHINE_UNKNOWN) {
 284       if (LibMachine == COFF::IMAGE_FILE_MACHINE_UNKNOWN) {
 285         if (FileMachine == COFF::IMAGE_FILE_MACHINE_ARM64EC) {
 286             llvm::errs() << MB.getBufferIdentifier() << ": file machine type "
 287                          << machineToStr(FileMachine)
 288                          << " conflicts with inferred library machine type,"
 289                          << " use /machine:arm64ec or /machine:arm64x\n";
 290             exit(1);
 291         }
 292         LibMachine = FileMachine;
 293         LibMachineSource =
 294             (" (inferred from earlier file '" + MB.getBufferIdentifier() + "')")
 295                 .str();
 296       } else if (!machineMatches(LibMachine, FileMachine)) {
 297         llvm::errs() << MB.getBufferIdentifier() << ": file machine type "
 298                      << machineToStr(FileMachine)
 299                      << " conflicts with library machine type "
 300                      << machineToStr(LibMachine) << LibMachineSource << '\n';
 301         exit(1);
 302       }
 303     }
 304   }
 305
 306   Members.emplace_back(MB);
 307 }
 308
 309 int llvm::libDriverMain(ArrayRef<const char *> ArgsArr) {
 310   BumpPtrAllocator Alloc;
 311   StringSaver Saver(Alloc);
 312
 313   // Parse command line arguments.
 314   SmallVector<const char *, 20> NewArgs(ArgsArr.begin(), ArgsArr.end());
 315   cl::ExpandResponseFiles(Saver, cl::TokenizeWindowsCommandLine, NewArgs);
 316   ArgsArr = NewArgs;
 317
 318   LibOptTable Table;
 319   unsigned MissingIndex;
 320   unsigned MissingCount;
 321   opt::InputArgList Args =
 322       Table.ParseArgs(ArgsArr.slice(1), MissingIndex, MissingCount);
 323   if (MissingCount) {
 324     llvm::errs() << "missing arg value for \""
 325                  << Args.getArgString(MissingIndex) << "\", expected "
 326                  << MissingCount
 327                  << (MissingCount == 1 ? " argument.\n" : " arguments.\n");
 328     return 1;
 329   }
 330   for (auto *Arg : Args.filtered(OPT_UNKNOWN))
 331     llvm::errs() << "ignoring unknown argument: " << Arg->getAsString(Args)
 332                  << "\n";
 333
 334   // Handle /help
 335   if (Args.hasArg(OPT_help)) {
 336     Table.printHelp(outs(), "llvm-lib [options] file...", "LLVM Lib");
 337     return 0;
 338   }
 339
 340   // Parse /ignore:
 341   llvm::StringSet<> IgnoredWarnings;
 342   for (auto *Arg : Args.filtered(OPT_ignore))
 343     IgnoredWarnings.insert(Arg->getValue());
 344
 345   // get output library path, if any
 346   std::string OutputPath;
 347   if (auto *Arg = Args.getLastArg(OPT_out)) {
 348     OutputPath = Arg->getValue();
 349   }
 350
 351   COFF::MachineTypes LibMachine = COFF::IMAGE_FILE_MACHINE_UNKNOWN;
 352   std::string LibMachineSource;
 353   if (auto *Arg = Args.getLastArg(OPT_machine)) {
 354     LibMachine = getMachineType(Arg->getValue());
 355     if (LibMachine == COFF::IMAGE_FILE_MACHINE_UNKNOWN) {
 356       llvm::errs() << "unknown /machine: arg " << Arg->getValue() << '\n';
 357       return 1;
 358     }
 359     LibMachineSource =
 360         std::string(" (from '/machine:") + Arg->getValue() + "' flag)";
 361   }
 362
 363   // create an import library
 364   if (Args.hasArg(OPT_deffile)) {
 365
 366     if (OutputPath.empty()) {
 367       llvm::errs() << "no output path given\n";
 368       return 1;
 369     }
 370
 371     if (LibMachine == COFF::IMAGE_FILE_MACHINE_UNKNOWN) {
 372       llvm::errs() << "/def option requires /machine to be specified" << '\n';
 373       return 1;
 374     }
 375
 376     std::unique_ptr<MemoryBuffer> MB =
 377         openFile(Args.getLastArg(OPT_deffile)->getValue());
 378     if (!MB)
 379       return 1;
 380
 381     if (!MB->getBufferSize()) {
 382       llvm::errs() << "definition file empty\n";
 383       return 1;
 384     }
 385
 386     Expected<COFFModuleDefinition> Def =
 387         parseCOFFModuleDefinition(*MB, LibMachine, /*MingwDef=*/false);
 388
 389     if (!Def) {
 390       llvm::errs() << "error parsing definition\n"
 391                    << errorToErrorCode(Def.takeError()).message();
 392       return 1;
 393     }
 394
 395     return writeImportLibrary(Def->OutputFile, OutputPath, Def->Exports,
 396                               LibMachine,
 397                               /*MinGW=*/false)
 398                ? 1
 399                : 0;
 400   }
 401
 402   // If no input files and not told otherwise, silently do nothing to match
 403   // lib.exe
 404   if (!Args.hasArgNoClaim(OPT_INPUT) && !Args.hasArg(OPT_llvmlibempty)) {
 405     if (!IgnoredWarnings.contains("emptyoutput")) {
 406       llvm::errs() << "warning: no input files, not writing output file\n";
 407       llvm::errs() << "         pass /llvmlibempty to write empty .lib file,\n";
 408       llvm::errs() << "         pass /ignore:emptyoutput to suppress warning\n";
 409       if (Args.hasFlag(OPT_WX, OPT_WX_no, false)) {
 410         llvm::errs() << "treating warning as error due to /WX\n";
 411         return 1;
 412       }
 413     }
 414     return 0;
 415   }
 416
 417   if (Args.hasArg(OPT_lst)) {
 418     doList(Args);
 419     return 0;
 420   }
 421
 422   std::vector<StringRef> SearchPaths = getSearchPaths(&Args, Saver);
 423
 424   std::vector<std::unique_ptr<MemoryBuffer>> MBs;
 425   StringSet<> Seen;
 426   std::vector<NewArchiveMember> Members;
 427
 428   // Create a NewArchiveMember for each input file.
 429   for (auto *Arg : Args.filtered(OPT_INPUT)) {
 430     // Find a file
 431     std::string Path = findInputFile(Arg->getValue(), SearchPaths);
 432     if (Path.empty()) {
 433       llvm::errs() << Arg->getValue() << ": no such file or directory\n";
 434       return 1;
 435     }
 436
 437     // Input files are uniquified by pathname. If you specify the exact same
 438     // path more than once, all but the first one are ignored.
 439     //
 440     // Note that there's a loophole in the rule; you can prepend `.\` or
 441     // something like that to a path to make it look different, and they are
 442     // handled as if they were different files. This behavior is compatible with
 443     // Microsoft lib.exe.
 444     if (!Seen.insert(Path).second)
 445       continue;
 446
 447     // Open a file.
 448     ErrorOr<std::unique_ptr<MemoryBuffer>> MOrErr = MemoryBuffer::getFile(
 449         Path, /*IsText=*/false, /*RequiresNullTerminator=*/false);
 450     fatalOpenError(errorCodeToError(MOrErr.getError()), Path);
 451     MemoryBufferRef MBRef = (*MOrErr)->getMemBufferRef();
 452
 453     // Append a file.
 454     appendFile(Members, LibMachine, LibMachineSource, MBRef);
 455
 456     // Take the ownership of the file buffer to keep the file open.
 457     MBs.push_back(std::move(*MOrErr));
 458   }
 459
 460   // Create an archive file.
 461   if (OutputPath.empty()) {
 462     if (!Members.empty()) {
 463       OutputPath = getDefaultOutputPath(Members[0]);
 464     } else {
 465       llvm::errs() << "no output path given, and cannot infer with no inputs\n";
 466       return 1;
 467     }
 468   }
 469   // llvm-lib uses relative paths for both regular and thin archives, unlike
 470   // standard GNU ar, which only uses relative paths for thin archives and
 471   // basenames for regular archives.
 472   for (NewArchiveMember &Member : Members) {
 473     if (sys::path::is_relative(Member.MemberName)) {
 474       Expected<std::string> PathOrErr =
 475           computeArchiveRelativePath(OutputPath, Member.MemberName);
 476       if (PathOrErr)
 477         Member.MemberName = Saver.save(*PathOrErr);
 478     }
 479   }
 480
 481   // For compatibility with MSVC, reverse member vector after de-duplication.
 482   std::reverse(Members.begin(), Members.end());
 483
 484   bool Thin = Args.hasArg(OPT_llvmlibthin);
 485   if (Error E = writeArchive(
 486           OutputPath, Members, SymtabWritingMode::NormalSymtab,
 487           Thin ? object::Archive::K_GNU : object::Archive::K_COFF,
 488           /*Deterministic=*/true, Thin, nullptr, COFF::isArm64EC(LibMachine))) {
 489     handleAllErrors(std::move(E), [&](const ErrorInfoBase &EI) {
 490       llvm::errs() << OutputPath << ": " << EI.message() << "\n";
 491     });
 492     return 1;
 493   }
 494
 495   return 0;
 496 }