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 getOutputPath(opt::InputArgList *Args,
  63                                  const NewArchiveMember &FirstMember) {
  64   if (auto *Arg = Args->getLastArg(OPT_out))
  65     return Arg->getValue();
  66   SmallString<128> Val = StringRef(FirstMember.Buf->getBufferIdentifier());
  67   sys::path::replace_extension(Val, ".lib");
  68   return Val.str();
  69 }
  70
  71 static std::vector<StringRef> getSearchPaths(opt::InputArgList *Args,
  72                                              StringSaver &Saver) {
  73   std::vector<StringRef> Ret;
  74   // Add current directory as first item of the search path.
  75   Ret.push_back("");
  76
  77   // Add /libpath flags.
  78   for (auto *Arg : Args->filtered(OPT_libpath))
  79     Ret.push_back(Arg->getValue());
  80
  81   // Add $LIB.
  82   Optional<std::string> EnvOpt = sys::Process::GetEnv("LIB");
  83   if (!EnvOpt.hasValue())
  84     return Ret;
  85   StringRef Env = Saver.save(*EnvOpt);
  86   while (!Env.empty()) {
  87     StringRef Path;
  88     std::tie(Path, Env) = Env.split(';');
  89     Ret.push_back(Path);
  90   }
  91   return Ret;
  92 }
  93
  94 static std::string findInputFile(StringRef File, ArrayRef<StringRef> Paths) {
  95   for (StringRef Dir : Paths) {
  96     SmallString<128> Path = Dir;
  97     sys::path::append(Path, File);
  98     if (sys::fs::exists(Path))
  99       return Path.str().str();
 100   }
 101   return "";
 102 }
 103
 104 static void fatalOpenError(llvm::Error E, Twine File) {
 105   if (!E)
 106     return;
 107   handleAllErrors(std::move(E), [&](const llvm::ErrorInfoBase &EIB) {
 108     llvm::errs() << "error opening '" << File << "': " << EIB.message() << '\n';
 109     exit(1);
 110   });
 111 }
 112
 113 static void doList(opt::InputArgList& Args) {
 114   // lib.exe prints the contents of the first archive file.
 115   std::unique_ptr<MemoryBuffer> B;
 116   for (auto *Arg : Args.filtered(OPT_INPUT)) {
 117     // Create or open the archive object.
 118     ErrorOr<std::unique_ptr<MemoryBuffer>> MaybeBuf =
 119         MemoryBuffer::getFile(Arg->getValue(), -1, false);
 120     fatalOpenError(errorCodeToError(MaybeBuf.getError()), Arg->getValue());
 121
 122     if (identify_magic(MaybeBuf.get()->getBuffer()) == file_magic::archive) {
 123       B = std::move(MaybeBuf.get());
 124       break;
 125     }
 126   }
 127
 128   // lib.exe doesn't print an error if no .lib files are passed.
 129   if (!B)
 130     return;
 131
 132   Error Err = Error::success();
 133   object::Archive Archive(B.get()->getMemBufferRef(), Err);
 134   fatalOpenError(std::move(Err), B->getBufferIdentifier());
 135
 136   for (auto &C : Archive.children(Err)) {
 137     Expected<StringRef> NameOrErr = C.getName();
 138     fatalOpenError(NameOrErr.takeError(), B->getBufferIdentifier());
 139     StringRef Name = NameOrErr.get();
 140     llvm::outs() << Name << '\n';
 141   }
 142   fatalOpenError(std::move(Err), B->getBufferIdentifier());
 143 }
 144
 145 static COFF::MachineTypes getCOFFFileMachine(MemoryBufferRef MB) {
 146   std::error_code EC;
 147   object::COFFObjectFile Obj(MB, EC);
 148   if (EC) {
 149     llvm::errs() << MB.getBufferIdentifier()
 150                  << ": failed to open: " << EC.message() << '\n';
 151     exit(1);
 152   }
 153
 154   uint16_t Machine = Obj.getMachine();
 155   if (Machine != COFF::IMAGE_FILE_MACHINE_I386 &&
 156       Machine != COFF::IMAGE_FILE_MACHINE_AMD64 &&
 157       Machine != COFF::IMAGE_FILE_MACHINE_ARMNT &&
 158       Machine != COFF::IMAGE_FILE_MACHINE_ARM64) {
 159     llvm::errs() << MB.getBufferIdentifier() << ": unknown machine: " << Machine
 160                  << '\n';
 161     exit(1);
 162   }
 163
 164   return static_cast<COFF::MachineTypes>(Machine);
 165 }
 166
 167 static COFF::MachineTypes getBitcodeFileMachine(MemoryBufferRef MB) {
 168   Expected<std::string> TripleStr = getBitcodeTargetTriple(MB);
 169   if (!TripleStr) {
 170     llvm::errs() << MB.getBufferIdentifier()
 171                  << ": failed to get target triple from bitcode\n";
 172     exit(1);
 173   }
 174
 175   switch (Triple(*TripleStr).getArch()) {
 176   case Triple::x86:
 177     return COFF::IMAGE_FILE_MACHINE_I386;
 178   case Triple::x86_64:
 179     return COFF::IMAGE_FILE_MACHINE_AMD64;
 180   case Triple::arm:
 181     return COFF::IMAGE_FILE_MACHINE_ARMNT;
 182   case Triple::aarch64:
 183     return COFF::IMAGE_FILE_MACHINE_ARM64;
 184   default:
 185     llvm::errs() << MB.getBufferIdentifier()
 186                  << ": unknown arch in target triple " << *TripleStr << '\n';
 187     exit(1);
 188   }
 189 }
 190
 191 static void appendFile(std::vector<NewArchiveMember> &Members,
 192                        COFF::MachineTypes &LibMachine,
 193                        std::string &LibMachineSource, MemoryBufferRef MB) {
 194   file_magic Magic = identify_magic(MB.getBuffer());
 195
 196   if (Magic != file_magic::coff_object && Magic != file_magic::bitcode &&
 197       Magic != file_magic::archive && Magic != file_magic::windows_resource) {
 198     llvm::errs() << MB.getBufferIdentifier()
 199                  << ": not a COFF object, bitcode, archive or resource file\n";
 200     exit(1);
 201   }
 202
 203   // If a user attempts to add an archive to another archive, llvm-lib doesn't
 204   // handle the first archive file as a single file. Instead, it extracts all
 205   // members from the archive and add them to the second archive. This beahvior
 206   // is for compatibility with Microsoft's lib command.
 207   if (Magic == file_magic::archive) {
 208     Error Err = Error::success();
 209     object::Archive Archive(MB, Err);
 210     fatalOpenError(std::move(Err), MB.getBufferIdentifier());
 211
 212     for (auto &C : Archive.children(Err)) {
 213       Expected<MemoryBufferRef> ChildMB = C.getMemoryBufferRef();
 214       if (!ChildMB) {
 215         handleAllErrors(ChildMB.takeError(), [&](const ErrorInfoBase &EIB) {
 216           llvm::errs() << MB.getBufferIdentifier() << ": " << EIB.message()
 217                        << "\n";
 218         });
 219         exit(1);
 220       }
 221
 222       appendFile(Members, LibMachine, LibMachineSource, *ChildMB);
 223     }
 224
 225     fatalOpenError(std::move(Err), MB.getBufferIdentifier());
 226     return;
 227   }
 228
 229   // Check that all input files have the same machine type.
 230   // Mixing normal objects and LTO bitcode files is fine as long as they
 231   // have the same machine type.
 232   // Doing this here duplicates the header parsing work that writeArchive()
 233   // below does, but it's not a lot of work and it's a bit awkward to do
 234   // in writeArchive() which needs to support many tools, can't assume the
 235   // input is COFF, and doesn't have a good way to report errors.
 236   if (Magic == file_magic::coff_object || Magic == file_magic::bitcode) {
 237     COFF::MachineTypes FileMachine = (Magic == file_magic::coff_object)
 238                                          ? getCOFFFileMachine(MB)
 239                                          : getBitcodeFileMachine(MB);
 240
 241     // FIXME: Once lld-link rejects multiple resource .obj files:
 242     // Call convertResToCOFF() on .res files and add the resulting
 243     // COFF file to the .lib output instead of adding the .res file, and remove
 244     // this check. See PR42180.
 245     if (FileMachine != COFF::IMAGE_FILE_MACHINE_UNKNOWN) {
 246       if (LibMachine == COFF::IMAGE_FILE_MACHINE_UNKNOWN) {
 247         LibMachine = FileMachine;
 248         LibMachineSource =
 249             (" (inferred from earlier file '" + MB.getBufferIdentifier() + "')")
 250                 .str();
 251       } else if (LibMachine != FileMachine) {
 252         llvm::errs() << MB.getBufferIdentifier() << ": file machine type "
 253                      << machineToStr(FileMachine)
 254                      << " conflicts with library machine type "
 255                      << machineToStr(LibMachine) << LibMachineSource << '\n';
 256         exit(1);
 257       }
 258     }
 259   }
 260
 261   Members.emplace_back(MB);
 262 }
 263
 264 int llvm::libDriverMain(ArrayRef<const char *> ArgsArr) {
 265   BumpPtrAllocator Alloc;
 266   StringSaver Saver(Alloc);
 267
 268   // Parse command line arguments.
 269   SmallVector<const char *, 20> NewArgs(ArgsArr.begin(), ArgsArr.end());
 270   cl::ExpandResponseFiles(Saver, cl::TokenizeWindowsCommandLine, NewArgs);
 271   ArgsArr = NewArgs;
 272
 273   LibOptTable Table;
 274   unsigned MissingIndex;
 275   unsigned MissingCount;
 276   opt::InputArgList Args =
 277       Table.ParseArgs(ArgsArr.slice(1), MissingIndex, MissingCount);
 278   if (MissingCount) {
 279     llvm::errs() << "missing arg value for \""
 280                  << Args.getArgString(MissingIndex) << "\", expected "
 281                  << MissingCount
 282                  << (MissingCount == 1 ? " argument.\n" : " arguments.\n");
 283     return 1;
 284   }
 285   for (auto *Arg : Args.filtered(OPT_UNKNOWN))
 286     llvm::errs() << "ignoring unknown argument: " << Arg->getAsString(Args)
 287                  << "\n";
 288
 289   // Handle /help
 290   if (Args.hasArg(OPT_help)) {
 291     Table.PrintHelp(outs(), "llvm-lib [options] file...", "LLVM Lib");
 292     return 0;
 293   }
 294
 295   // If no input files, silently do nothing to match lib.exe.
 296   if (!Args.hasArgNoClaim(OPT_INPUT))
 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 =
 343         MemoryBuffer::getFile(Path, -1, 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 = getOutputPath(&Args, Members[0]);
 356   // llvm-lib uses relative paths for both regular and thin archives, unlike
 357   // standard GNU ar, which only uses relative paths for thin archives and
 358   // basenames for regular archives.
 359   for (NewArchiveMember &Member : Members) {
 360     if (sys::path::is_relative(Member.MemberName)) {
 361       Expected<std::string> PathOrErr =
 362           computeArchiveRelativePath(OutputPath, Member.MemberName);
 363       if (PathOrErr)
 364         Member.MemberName = Saver.save(*PathOrErr);
 365     }
 366   }
 367
 368   if (Error E =
 369           writeArchive(OutputPath, Members,
 370                        /*WriteSymtab=*/true, object::Archive::K_GNU,
 371                        /*Deterministic*/ true, Args.hasArg(OPT_llvmlibthin))) {
 372     handleAllErrors(std::move(E), [&](const ErrorInfoBase &EI) {
 373       llvm::errs() << OutputPath << ": " << EI.message() << "\n";
 374     });
 375     return 1;
 376   }
 377
 378   return 0;
 379 }