xref: /freebsd/contrib/llvm-project/llvm/lib/ToolDrivers/llvm-lib/LibDriver.cpp (revision 77a1348b3c1cfe8547be49a121b56299a1e18b69) 
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 }
380