xref: /llvm-project/llvm/lib/ToolDrivers/llvm-lib/LibDriver.cpp (revision d546b5052bb71ad90230fa572101730d4c0246a3) 
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/BinaryFormat/COFF.h"
17 #include "llvm/BinaryFormat/Magic.h"
18 #include "llvm/Bitcode/BitcodeReader.h"
19 #include "llvm/Object/ArchiveWriter.h"
20 #include "llvm/Object/COFF.h"
21 #include "llvm/Option/Arg.h"
22 #include "llvm/Option/ArgList.h"
23 #include "llvm/Option/Option.h"
24 #include "llvm/Support/CommandLine.h"
25 #include "llvm/Support/Path.h"
26 #include "llvm/Support/Process.h"
27 #include "llvm/Support/StringSaver.h"
28 #include "llvm/Support/raw_ostream.h"
29 
30 using namespace llvm;
31 
32 namespace {
33 
34 enum {
35   OPT_INVALID = 0,
36 #define OPTION(_1, _2, ID, _4, _5, _6, _7, _8, _9, _10, _11, _12) OPT_##ID,
37 #include "Options.inc"
38 #undef OPTION
39 };
40 
41 #define PREFIX(NAME, VALUE) const char *const NAME[] = VALUE;
42 #include "Options.inc"
43 #undef PREFIX
44 
45 static const opt::OptTable::Info InfoTable[] = {
46 #define OPTION(X1, X2, ID, KIND, GROUP, ALIAS, X7, X8, X9, X10, X11, X12)      \
47   {X1, X2, X10,         X11,         OPT_##ID, opt::Option::KIND##Class,       \
48    X9, X8, OPT_##GROUP, OPT_##ALIAS, X7,       X12},
49 #include "Options.inc"
50 #undef OPTION
51 };
52 
53 class LibOptTable : public opt::OptTable {
54 public:
55   LibOptTable() : OptTable(InfoTable, true) {}
56 };
57 
58 }
59 
60 static std::string getOutputPath(opt::InputArgList *Args,
61                                  const NewArchiveMember &FirstMember) {
62   if (auto *Arg = Args->getLastArg(OPT_out))
63     return Arg->getValue();
64   SmallString<128> Val = StringRef(FirstMember.Buf->getBufferIdentifier());
65   sys::path::replace_extension(Val, ".lib");
66   return Val.str();
67 }
68 
69 static std::vector<StringRef> getSearchPaths(opt::InputArgList *Args,
70                                              StringSaver &Saver) {
71   std::vector<StringRef> Ret;
72   // Add current directory as first item of the search path.
73   Ret.push_back("");
74 
75   // Add /libpath flags.
76   for (auto *Arg : Args->filtered(OPT_libpath))
77     Ret.push_back(Arg->getValue());
78 
79   // Add $LIB.
80   Optional<std::string> EnvOpt = sys::Process::GetEnv("LIB");
81   if (!EnvOpt.hasValue())
82     return Ret;
83   StringRef Env = Saver.save(*EnvOpt);
84   while (!Env.empty()) {
85     StringRef Path;
86     std::tie(Path, Env) = Env.split(';');
87     Ret.push_back(Path);
88   }
89   return Ret;
90 }
91 
92 static std::string findInputFile(StringRef File, ArrayRef<StringRef> Paths) {
93   for (StringRef Dir : Paths) {
94     SmallString<128> Path = Dir;
95     sys::path::append(Path, File);
96     if (sys::fs::exists(Path))
97       return Path.str().str();
98   }
99   return "";
100 }
101 
102 static void fatalOpenError(llvm::Error E, Twine File) {
103   if (!E)
104     return;
105   handleAllErrors(std::move(E), [&](const llvm::ErrorInfoBase &EIB) {
106     llvm::errs() << "error opening '" << File << "': " << EIB.message() << '\n';
107     exit(1);
108   });
109 }
110 
111 static void doList(opt::InputArgList& Args) {
112   // lib.exe prints the contents of the first archive file.
113   std::unique_ptr<MemoryBuffer> B;
114   for (auto *Arg : Args.filtered(OPT_INPUT)) {
115     // Create or open the archive object.
116     ErrorOr<std::unique_ptr<MemoryBuffer>> MaybeBuf =
117         MemoryBuffer::getFile(Arg->getValue(), -1, false);
118     fatalOpenError(errorCodeToError(MaybeBuf.getError()), Arg->getValue());
119 
120     if (identify_magic(MaybeBuf.get()->getBuffer()) == file_magic::archive) {
121       B = std::move(MaybeBuf.get());
122       break;
123     }
124   }
125 
126   // lib.exe doesn't print an error if no .lib files are passed.
127   if (!B)
128     return;
129 
130   Error Err = Error::success();
131   object::Archive Archive(B.get()->getMemBufferRef(), Err);
132   fatalOpenError(std::move(Err), B->getBufferIdentifier());
133 
134   for (auto &C : Archive.children(Err)) {
135     Expected<StringRef> NameOrErr = C.getName();
136     fatalOpenError(NameOrErr.takeError(), B->getBufferIdentifier());
137     StringRef Name = NameOrErr.get();
138     llvm::outs() << Name << '\n';
139   }
140   fatalOpenError(std::move(Err), B->getBufferIdentifier());
141 }
142 
143 static StringRef machineToStr(COFF::MachineTypes MT) {
144   switch (MT) {
145   case COFF::IMAGE_FILE_MACHINE_ARMNT:
146     return "arm";
147   case COFF::IMAGE_FILE_MACHINE_ARM64:
148     return "arm64";
149   case COFF::IMAGE_FILE_MACHINE_AMD64:
150     return "x64";
151   case COFF::IMAGE_FILE_MACHINE_I386:
152     return "x86";
153   default:
154     llvm_unreachable("unknown machine type");
155   }
156 }
157 
158 int llvm::libDriverMain(ArrayRef<const char *> ArgsArr) {
159   BumpPtrAllocator Alloc;
160   StringSaver Saver(Alloc);
161 
162   // Parse command line arguments.
163   SmallVector<const char *, 20> NewArgs(ArgsArr.begin(), ArgsArr.end());
164   cl::ExpandResponseFiles(Saver, cl::TokenizeWindowsCommandLine, NewArgs);
165   ArgsArr = NewArgs;
166 
167   LibOptTable Table;
168   unsigned MissingIndex;
169   unsigned MissingCount;
170   opt::InputArgList Args =
171       Table.ParseArgs(ArgsArr.slice(1), MissingIndex, MissingCount);
172   if (MissingCount) {
173     llvm::errs() << "missing arg value for \""
174                  << Args.getArgString(MissingIndex) << "\", expected "
175                  << MissingCount
176                  << (MissingCount == 1 ? " argument.\n" : " arguments.\n");
177     return 1;
178   }
179   for (auto *Arg : Args.filtered(OPT_UNKNOWN))
180     llvm::errs() << "ignoring unknown argument: " << Arg->getSpelling() << "\n";
181 
182   // Handle /help
183   if (Args.hasArg(OPT_help)) {
184     Table.PrintHelp(outs(), "llvm-lib [options] file...", "LLVM Lib");
185     return 0;
186   }
187 
188   // If no input files, silently do nothing to match lib.exe.
189   if (!Args.hasArgNoClaim(OPT_INPUT))
190     return 0;
191 
192   if (Args.hasArg(OPT_lst)) {
193     doList(Args);
194     return 0;
195   }
196 
197   std::vector<StringRef> SearchPaths = getSearchPaths(&Args, Saver);
198 
199   // Create a NewArchiveMember for each input file.
200   std::vector<NewArchiveMember> Members;
201   COFF::MachineTypes LibMachine = COFF::IMAGE_FILE_MACHINE_UNKNOWN;
202   for (auto *Arg : Args.filtered(OPT_INPUT)) {
203     std::string Path = findInputFile(Arg->getValue(), SearchPaths);
204     if (Path.empty()) {
205       llvm::errs() << Arg->getValue() << ": no such file or directory\n";
206       return 1;
207     }
208 
209     Expected<NewArchiveMember> MOrErr =
210         NewArchiveMember::getFile(Saver.save(Path), /*Deterministic=*/true);
211     if (!MOrErr) {
212       handleAllErrors(MOrErr.takeError(), [&](const ErrorInfoBase &EIB) {
213         llvm::errs() << Arg->getValue() << ": " << EIB.message() << "\n";
214       });
215       return 1;
216     }
217 
218     file_magic Magic = identify_magic(MOrErr->Buf->getBuffer());
219     if (Magic != file_magic::coff_object && Magic != file_magic::bitcode &&
220         Magic != file_magic::windows_resource) {
221       llvm::errs() << Arg->getValue()
222                    << ": not a COFF object, bitcode or resource file\n";
223       return 1;
224     }
225 
226     // Check that all input files have the same machine type.
227     // Mixing normal objects and LTO bitcode files is fine as long as they
228     // have the same machine type.
229     // Doing this here duplicates the header parsing work that writeArchive()
230     // below does, but it's not a lot of work and it's a bit awkward to do
231     // in writeArchive() which needs to support many tools, can't assume the
232     // input is COFF, and doesn't have a good way to report errors.
233     COFF::MachineTypes FileMachine = COFF::IMAGE_FILE_MACHINE_UNKNOWN;
234     if (Magic == file_magic::coff_object) {
235       std::error_code EC;
236       object::COFFObjectFile Obj(*MOrErr->Buf, EC);
237       if (EC) {
238         llvm::errs() << Arg->getValue() << ": failed to open: " << EC.message()
239                      << '\n';
240         return 1;
241       }
242       uint16_t Machine = Obj.getMachine();
243       if (Machine != COFF::IMAGE_FILE_MACHINE_I386 &&
244           Machine != COFF::IMAGE_FILE_MACHINE_AMD64 &&
245           Machine != COFF::IMAGE_FILE_MACHINE_ARMNT &&
246           Machine != COFF::IMAGE_FILE_MACHINE_ARM64) {
247         llvm::errs() << Arg->getValue() << ": unknown machine: " << Machine
248                      << '\n';
249         return 1;
250       }
251       FileMachine = static_cast<COFF::MachineTypes>(Machine);
252     } else if (Magic == file_magic::bitcode) {
253       Expected<std::string> TripleStr = getBitcodeTargetTriple(*MOrErr->Buf);
254       if (!TripleStr) {
255         llvm::errs() << Arg->getValue()
256                      << ": failed to get target triple from bitcode\n";
257         return 1;
258       }
259       switch (Triple(*TripleStr).getArch()) {
260       case Triple::x86:
261         FileMachine = COFF::IMAGE_FILE_MACHINE_I386;
262         break;
263       case Triple::x86_64:
264         FileMachine = COFF::IMAGE_FILE_MACHINE_AMD64;
265         break;
266       case Triple::arm:
267         FileMachine = COFF::IMAGE_FILE_MACHINE_ARMNT;
268         break;
269       case Triple::aarch64:
270         FileMachine = COFF::IMAGE_FILE_MACHINE_ARM64;
271         break;
272       default:
273         llvm::errs() << Arg->getValue() << ": unknown arch in target triple "
274                      << *TripleStr << '\n';
275         return 1;
276       }
277     }
278 
279     if (FileMachine != COFF::IMAGE_FILE_MACHINE_UNKNOWN) {
280       if (LibMachine == COFF::IMAGE_FILE_MACHINE_UNKNOWN)
281         LibMachine = FileMachine;
282       else if (LibMachine != FileMachine) {
283         llvm::errs() << Arg->getValue() << ": file machine type "
284                      << machineToStr(FileMachine)
285                      << " conflicts with library machine type "
286                      << machineToStr(LibMachine) << '\n';
287         return 1;
288       }
289     }
290 
291     Members.emplace_back(std::move(*MOrErr));
292   }
293 
294   // Create an archive file.
295   std::string OutputPath = getOutputPath(&Args, Members[0]);
296   // llvm-lib uses relative paths for both regular and thin archives, unlike
297   // standard GNU ar, which only uses relative paths for thin archives and
298   // basenames for regular archives.
299   for (NewArchiveMember &Member : Members) {
300     if (sys::path::is_relative(Member.MemberName)) {
301       Expected<std::string> PathOrErr =
302           computeArchiveRelativePath(OutputPath, Member.MemberName);
303       if (PathOrErr)
304         Member.MemberName = Saver.save(*PathOrErr);
305     }
306   }
307 
308   if (Error E =
309           writeArchive(OutputPath, Members,
310                        /*WriteSymtab=*/true, object::Archive::K_GNU,
311                        /*Deterministic*/ true, Args.hasArg(OPT_llvmlibthin))) {
312     handleAllErrors(std::move(E), [&](const ErrorInfoBase &EI) {
313       llvm::errs() << OutputPath << ": " << EI.message() << "\n";
314     });
315     return 1;
316   }
317 
318   return 0;
319 }
320