xref: /llvm-project/llvm/lib/ToolDrivers/llvm-lib/LibDriver.cpp (revision c912e98e8ea3678bf8344199a97530f7a310aed7) 
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 #define OPTTABLE_STR_TABLE_CODE
41 #include "Options.inc"
42 #undef OPTTABLE_STR_TABLE_CODE
43 
44 enum {
45   OPT_INVALID = 0,
46 #define OPTION(...) LLVM_MAKE_OPT_ID(__VA_ARGS__),
47 #include "Options.inc"
48 #undef OPTION
49 };
50 
51 #define OPTTABLE_PREFIXES_TABLE_CODE
52 #include "Options.inc"
53 #undef OPTTABLE_PREFIXES_TABLE_CODE
54 
55 using namespace llvm::opt;
56 static constexpr opt::OptTable::Info InfoTable[] = {
57 #define OPTION(...) LLVM_CONSTRUCT_OPT_INFO(__VA_ARGS__),
58 #include "Options.inc"
59 #undef OPTION
60 };
61 
62 class LibOptTable : public opt::GenericOptTable {
63 public:
64   LibOptTable()
65       : opt::GenericOptTable(OptionStrTable, OptionPrefixesTable, InfoTable,
66                              true) {}
67 };
68 } // namespace
69 
70 static std::string getDefaultOutputPath(const NewArchiveMember &FirstMember) {
71   SmallString<128> Val = StringRef(FirstMember.Buf->getBufferIdentifier());
72   sys::path::replace_extension(Val, ".lib");
73   return std::string(Val);
74 }
75 
76 static std::vector<StringRef> getSearchPaths(opt::InputArgList *Args,
77                                              StringSaver &Saver) {
78   std::vector<StringRef> Ret;
79   // Add current directory as first item of the search path.
80   Ret.push_back("");
81 
82   // Add /libpath flags.
83   for (auto *Arg : Args->filtered(OPT_libpath))
84     Ret.push_back(Arg->getValue());
85 
86   // Add $LIB.
87   std::optional<std::string> EnvOpt = sys::Process::GetEnv("LIB");
88   if (!EnvOpt)
89     return Ret;
90   StringRef Env = Saver.save(*EnvOpt);
91   while (!Env.empty()) {
92     StringRef Path;
93     std::tie(Path, Env) = Env.split(';');
94     Ret.push_back(Path);
95   }
96   return Ret;
97 }
98 
99 // Opens a file. Path has to be resolved already. (used for def file)
100 std::unique_ptr<MemoryBuffer> openFile(const Twine &Path) {
101   ErrorOr<std::unique_ptr<llvm::MemoryBuffer>> MB =
102       MemoryBuffer::getFile(Path, /*IsText=*/true);
103 
104   if (std::error_code EC = MB.getError()) {
105     llvm::errs() << "cannot open file " << Path << ": " << EC.message() << "\n";
106     return nullptr;
107   }
108 
109   return std::move(*MB);
110 }
111 
112 static std::string findInputFile(StringRef File, ArrayRef<StringRef> Paths) {
113   for (StringRef Dir : Paths) {
114     SmallString<128> Path = Dir;
115     sys::path::append(Path, File);
116     if (sys::fs::exists(Path))
117       return std::string(Path);
118   }
119   return "";
120 }
121 
122 static void fatalOpenError(llvm::Error E, Twine File) {
123   if (!E)
124     return;
125   handleAllErrors(std::move(E), [&](const llvm::ErrorInfoBase &EIB) {
126     llvm::errs() << "error opening '" << File << "': " << EIB.message() << '\n';
127     exit(1);
128   });
129 }
130 
131 static void doList(opt::InputArgList &Args) {
132   // lib.exe prints the contents of the first archive file.
133   std::unique_ptr<MemoryBuffer> B;
134   for (auto *Arg : Args.filtered(OPT_INPUT)) {
135     // Create or open the archive object.
136     ErrorOr<std::unique_ptr<MemoryBuffer>> MaybeBuf = MemoryBuffer::getFile(
137         Arg->getValue(), /*IsText=*/false, /*RequiresNullTerminator=*/false);
138     fatalOpenError(errorCodeToError(MaybeBuf.getError()), Arg->getValue());
139 
140     if (identify_magic(MaybeBuf.get()->getBuffer()) == file_magic::archive) {
141       B = std::move(MaybeBuf.get());
142       break;
143     }
144   }
145 
146   // lib.exe doesn't print an error if no .lib files are passed.
147   if (!B)
148     return;
149 
150   Error Err = Error::success();
151   object::Archive Archive(B->getMemBufferRef(), Err);
152   fatalOpenError(std::move(Err), B->getBufferIdentifier());
153 
154   std::vector<StringRef> Names;
155   for (auto &C : Archive.children(Err)) {
156     Expected<StringRef> NameOrErr = C.getName();
157     fatalOpenError(NameOrErr.takeError(), B->getBufferIdentifier());
158     Names.push_back(NameOrErr.get());
159   }
160   for (auto Name : reverse(Names))
161     llvm::outs() << Name << '\n';
162   fatalOpenError(std::move(Err), B->getBufferIdentifier());
163 }
164 
165 static Expected<COFF::MachineTypes> getCOFFFileMachine(MemoryBufferRef MB) {
166   std::error_code EC;
167   auto Obj = object::COFFObjectFile::create(MB);
168   if (!Obj)
169     return Obj.takeError();
170 
171   uint16_t Machine = (*Obj)->getMachine();
172   if (Machine != COFF::IMAGE_FILE_MACHINE_I386 &&
173       Machine != COFF::IMAGE_FILE_MACHINE_AMD64 &&
174       Machine != COFF::IMAGE_FILE_MACHINE_R4000 &&
175       Machine != COFF::IMAGE_FILE_MACHINE_ARMNT && !COFF::isAnyArm64(Machine)) {
176     return createStringError(inconvertibleErrorCode(),
177                              "unknown machine: " + std::to_string(Machine));
178   }
179 
180   return static_cast<COFF::MachineTypes>(Machine);
181 }
182 
183 static Expected<COFF::MachineTypes> getBitcodeFileMachine(MemoryBufferRef MB) {
184   Expected<std::string> TripleStr = getBitcodeTargetTriple(MB);
185   if (!TripleStr)
186     return TripleStr.takeError();
187 
188   Triple T(*TripleStr);
189   switch (T.getArch()) {
190   case Triple::x86:
191     return COFF::IMAGE_FILE_MACHINE_I386;
192   case Triple::x86_64:
193     return COFF::IMAGE_FILE_MACHINE_AMD64;
194   case Triple::arm:
195     return COFF::IMAGE_FILE_MACHINE_ARMNT;
196   case Triple::aarch64:
197     return T.isWindowsArm64EC() ? COFF::IMAGE_FILE_MACHINE_ARM64EC
198                                 : COFF::IMAGE_FILE_MACHINE_ARM64;
199   case Triple::mipsel:
200     return COFF::IMAGE_FILE_MACHINE_R4000;
201   default:
202     return createStringError(inconvertibleErrorCode(),
203                              "unknown arch in target triple: " + *TripleStr);
204   }
205 }
206 
207 static bool machineMatches(COFF::MachineTypes LibMachine,
208                            COFF::MachineTypes FileMachine) {
209   if (LibMachine == FileMachine)
210     return true;
211   // ARM64EC mode allows both pure ARM64, ARM64EC and X64 objects to be mixed in
212   // the archive.
213   switch (LibMachine) {
214   case COFF::IMAGE_FILE_MACHINE_ARM64:
215     return FileMachine == COFF::IMAGE_FILE_MACHINE_ARM64X;
216   case COFF::IMAGE_FILE_MACHINE_ARM64EC:
217   case COFF::IMAGE_FILE_MACHINE_ARM64X:
218     return COFF::isAnyArm64(FileMachine) ||
219            FileMachine == COFF::IMAGE_FILE_MACHINE_AMD64;
220   default:
221     return false;
222   }
223 }
224 
225 static void appendFile(std::vector<NewArchiveMember> &Members,
226                        COFF::MachineTypes &LibMachine,
227                        std::string &LibMachineSource, MemoryBufferRef MB) {
228   file_magic Magic = identify_magic(MB.getBuffer());
229 
230   if (Magic != file_magic::coff_object && Magic != file_magic::bitcode &&
231       Magic != file_magic::archive && Magic != file_magic::windows_resource &&
232       Magic != file_magic::coff_import_library) {
233     llvm::errs() << MB.getBufferIdentifier()
234                  << ": not a COFF object, bitcode, archive, import library or "
235                     "resource file\n";
236     exit(1);
237   }
238 
239   // If a user attempts to add an archive to another archive, llvm-lib doesn't
240   // handle the first archive file as a single file. Instead, it extracts all
241   // members from the archive and add them to the second archive. This behavior
242   // is for compatibility with Microsoft's lib command.
243   if (Magic == file_magic::archive) {
244     Error Err = Error::success();
245     object::Archive Archive(MB, Err);
246     fatalOpenError(std::move(Err), MB.getBufferIdentifier());
247 
248     for (auto &C : Archive.children(Err)) {
249       Expected<MemoryBufferRef> ChildMB = C.getMemoryBufferRef();
250       if (!ChildMB) {
251         handleAllErrors(ChildMB.takeError(), [&](const ErrorInfoBase &EIB) {
252           llvm::errs() << MB.getBufferIdentifier() << ": " << EIB.message()
253                        << "\n";
254         });
255         exit(1);
256       }
257 
258       appendFile(Members, LibMachine, LibMachineSource, *ChildMB);
259     }
260 
261     fatalOpenError(std::move(Err), MB.getBufferIdentifier());
262     return;
263   }
264 
265   // Check that all input files have the same machine type.
266   // Mixing normal objects and LTO bitcode files is fine as long as they
267   // have the same machine type.
268   // Doing this here duplicates the header parsing work that writeArchive()
269   // below does, but it's not a lot of work and it's a bit awkward to do
270   // in writeArchive() which needs to support many tools, can't assume the
271   // input is COFF, and doesn't have a good way to report errors.
272   if (Magic == file_magic::coff_object || Magic == file_magic::bitcode) {
273     Expected<COFF::MachineTypes> MaybeFileMachine =
274         (Magic == file_magic::coff_object) ? getCOFFFileMachine(MB)
275                                            : getBitcodeFileMachine(MB);
276     if (!MaybeFileMachine) {
277       handleAllErrors(MaybeFileMachine.takeError(),
278                       [&](const ErrorInfoBase &EIB) {
279                         llvm::errs() << MB.getBufferIdentifier() << ": "
280                                      << EIB.message() << "\n";
281                       });
282       exit(1);
283     }
284     COFF::MachineTypes FileMachine = *MaybeFileMachine;
285 
286     // FIXME: Once lld-link rejects multiple resource .obj files:
287     // Call convertResToCOFF() on .res files and add the resulting
288     // COFF file to the .lib output instead of adding the .res file, and remove
289     // this check. See PR42180.
290     if (FileMachine != COFF::IMAGE_FILE_MACHINE_UNKNOWN) {
291       if (LibMachine == COFF::IMAGE_FILE_MACHINE_UNKNOWN) {
292         if (FileMachine == COFF::IMAGE_FILE_MACHINE_ARM64EC) {
293             llvm::errs() << MB.getBufferIdentifier() << ": file machine type "
294                          << machineToStr(FileMachine)
295                          << " conflicts with inferred library machine type,"
296                          << " use /machine:arm64ec or /machine:arm64x\n";
297             exit(1);
298         }
299         LibMachine = FileMachine;
300         LibMachineSource =
301             (" (inferred from earlier file '" + MB.getBufferIdentifier() + "')")
302                 .str();
303       } else if (!machineMatches(LibMachine, FileMachine)) {
304         llvm::errs() << MB.getBufferIdentifier() << ": file machine type "
305                      << machineToStr(FileMachine)
306                      << " conflicts with library machine type "
307                      << machineToStr(LibMachine) << LibMachineSource << '\n';
308         exit(1);
309       }
310     }
311   }
312 
313   Members.emplace_back(MB);
314 }
315 
316 int llvm::libDriverMain(ArrayRef<const char *> ArgsArr) {
317   BumpPtrAllocator Alloc;
318   StringSaver Saver(Alloc);
319 
320   // Parse command line arguments.
321   SmallVector<const char *, 20> NewArgs(ArgsArr);
322   cl::ExpandResponseFiles(Saver, cl::TokenizeWindowsCommandLine, NewArgs);
323   ArgsArr = NewArgs;
324 
325   LibOptTable Table;
326   unsigned MissingIndex;
327   unsigned MissingCount;
328   opt::InputArgList Args =
329       Table.ParseArgs(ArgsArr.slice(1), MissingIndex, MissingCount);
330   if (MissingCount) {
331     llvm::errs() << "missing arg value for \""
332                  << Args.getArgString(MissingIndex) << "\", expected "
333                  << MissingCount
334                  << (MissingCount == 1 ? " argument.\n" : " arguments.\n");
335     return 1;
336   }
337   for (auto *Arg : Args.filtered(OPT_UNKNOWN))
338     llvm::errs() << "ignoring unknown argument: " << Arg->getAsString(Args)
339                  << "\n";
340 
341   // Handle /help
342   if (Args.hasArg(OPT_help)) {
343     Table.printHelp(outs(), "llvm-lib [options] file...", "LLVM Lib");
344     return 0;
345   }
346 
347   // Parse /ignore:
348   llvm::StringSet<> IgnoredWarnings;
349   for (auto *Arg : Args.filtered(OPT_ignore))
350     IgnoredWarnings.insert(Arg->getValue());
351 
352   // get output library path, if any
353   std::string OutputPath;
354   if (auto *Arg = Args.getLastArg(OPT_out)) {
355     OutputPath = Arg->getValue();
356   }
357 
358   COFF::MachineTypes LibMachine = COFF::IMAGE_FILE_MACHINE_UNKNOWN;
359   std::string LibMachineSource;
360   if (auto *Arg = Args.getLastArg(OPT_machine)) {
361     LibMachine = getMachineType(Arg->getValue());
362     if (LibMachine == COFF::IMAGE_FILE_MACHINE_UNKNOWN) {
363       llvm::errs() << "unknown /machine: arg " << Arg->getValue() << '\n';
364       return 1;
365     }
366     LibMachineSource =
367         std::string(" (from '/machine:") + Arg->getValue() + "' flag)";
368   }
369 
370   // create an import library
371   if (Args.hasArg(OPT_deffile)) {
372 
373     if (OutputPath.empty()) {
374       llvm::errs() << "no output path given\n";
375       return 1;
376     }
377 
378     if (LibMachine == COFF::IMAGE_FILE_MACHINE_UNKNOWN) {
379       llvm::errs() << "/def option requires /machine to be specified" << '\n';
380       return 1;
381     }
382 
383     std::unique_ptr<MemoryBuffer> MB =
384         openFile(Args.getLastArg(OPT_deffile)->getValue());
385     if (!MB)
386       return 1;
387 
388     if (!MB->getBufferSize()) {
389       llvm::errs() << "definition file empty\n";
390       return 1;
391     }
392 
393     Expected<COFFModuleDefinition> Def =
394         parseCOFFModuleDefinition(*MB, LibMachine, /*MingwDef=*/false);
395 
396     if (!Def) {
397       llvm::errs() << "error parsing definition\n"
398                    << errorToErrorCode(Def.takeError()).message();
399       return 1;
400     }
401 
402     std::vector<COFFShortExport> NativeExports;
403     std::string OutputFile = Def->OutputFile;
404 
405     if (isArm64EC(LibMachine) && Args.hasArg(OPT_nativedeffile)) {
406       std::unique_ptr<MemoryBuffer> NativeMB =
407           openFile(Args.getLastArg(OPT_nativedeffile)->getValue());
408       if (!NativeMB)
409         return 1;
410 
411       if (!NativeMB->getBufferSize()) {
412         llvm::errs() << "native definition file empty\n";
413         return 1;
414       }
415 
416       Expected<COFFModuleDefinition> NativeDef =
417           parseCOFFModuleDefinition(*NativeMB, COFF::IMAGE_FILE_MACHINE_ARM64);
418 
419       if (!NativeDef) {
420         llvm::errs() << "error parsing native definition\n"
421                      << errorToErrorCode(NativeDef.takeError()).message();
422         return 1;
423       }
424       NativeExports = std::move(NativeDef->Exports);
425       OutputFile = std::move(NativeDef->OutputFile);
426     }
427 
428     if (Error E =
429             writeImportLibrary(OutputFile, OutputPath, Def->Exports, LibMachine,
430                                /*MinGW=*/false, NativeExports)) {
431       handleAllErrors(std::move(E), [&](const ErrorInfoBase &EI) {
432         llvm::errs() << OutputPath << ": " << EI.message() << "\n";
433       });
434       return 1;
435     }
436     return 0;
437   }
438 
439   // If no input files and not told otherwise, silently do nothing to match
440   // lib.exe
441   if (!Args.hasArgNoClaim(OPT_INPUT) && !Args.hasArg(OPT_llvmlibempty)) {
442     if (!IgnoredWarnings.contains("emptyoutput")) {
443       llvm::errs() << "warning: no input files, not writing output file\n";
444       llvm::errs() << "         pass /llvmlibempty to write empty .lib file,\n";
445       llvm::errs() << "         pass /ignore:emptyoutput to suppress warning\n";
446       if (Args.hasFlag(OPT_WX, OPT_WX_no, false)) {
447         llvm::errs() << "treating warning as error due to /WX\n";
448         return 1;
449       }
450     }
451     return 0;
452   }
453 
454   if (Args.hasArg(OPT_lst)) {
455     doList(Args);
456     return 0;
457   }
458 
459   std::vector<StringRef> SearchPaths = getSearchPaths(&Args, Saver);
460 
461   std::vector<std::unique_ptr<MemoryBuffer>> MBs;
462   StringSet<> Seen;
463   std::vector<NewArchiveMember> Members;
464 
465   // Create a NewArchiveMember for each input file.
466   for (auto *Arg : Args.filtered(OPT_INPUT)) {
467     // Find a file
468     std::string Path = findInputFile(Arg->getValue(), SearchPaths);
469     if (Path.empty()) {
470       llvm::errs() << Arg->getValue() << ": no such file or directory\n";
471       return 1;
472     }
473 
474     // Input files are uniquified by pathname. If you specify the exact same
475     // path more than once, all but the first one are ignored.
476     //
477     // Note that there's a loophole in the rule; you can prepend `.\` or
478     // something like that to a path to make it look different, and they are
479     // handled as if they were different files. This behavior is compatible with
480     // Microsoft lib.exe.
481     if (!Seen.insert(Path).second)
482       continue;
483 
484     // Open a file.
485     ErrorOr<std::unique_ptr<MemoryBuffer>> MOrErr = MemoryBuffer::getFile(
486         Path, /*IsText=*/false, /*RequiresNullTerminator=*/false);
487     fatalOpenError(errorCodeToError(MOrErr.getError()), Path);
488     MemoryBufferRef MBRef = (*MOrErr)->getMemBufferRef();
489 
490     // Append a file.
491     appendFile(Members, LibMachine, LibMachineSource, MBRef);
492 
493     // Take the ownership of the file buffer to keep the file open.
494     MBs.push_back(std::move(*MOrErr));
495   }
496 
497   // Create an archive file.
498   if (OutputPath.empty()) {
499     if (!Members.empty()) {
500       OutputPath = getDefaultOutputPath(Members[0]);
501     } else {
502       llvm::errs() << "no output path given, and cannot infer with no inputs\n";
503       return 1;
504     }
505   }
506 
507   bool Thin = Args.hasArg(OPT_llvmlibthin);
508   if (Thin) {
509     for (NewArchiveMember &Member : Members) {
510       if (sys::path::is_relative(Member.MemberName)) {
511         Expected<std::string> PathOrErr =
512             computeArchiveRelativePath(OutputPath, Member.MemberName);
513         if (PathOrErr)
514           Member.MemberName = Saver.save(*PathOrErr);
515       }
516     }
517   }
518 
519   // For compatibility with MSVC, reverse member vector after de-duplication.
520   std::reverse(Members.begin(), Members.end());
521 
522   auto Symtab = Args.hasFlag(OPT_llvmlibindex, OPT_llvmlibindex_no,
523                              /*default=*/true)
524                     ? SymtabWritingMode::NormalSymtab
525                     : SymtabWritingMode::NoSymtab;
526 
527   if (Error E = writeArchive(
528           OutputPath, Members, Symtab,
529           Thin ? object::Archive::K_GNU : object::Archive::K_COFF,
530           /*Deterministic=*/true, Thin, nullptr, COFF::isArm64EC(LibMachine))) {
531     handleAllErrors(std::move(E), [&](const ErrorInfoBase &EI) {
532       llvm::errs() << OutputPath << ": " << EI.message() << "\n";
533     });
534     return 1;
535   }
536 
537   return 0;
538 }
539