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 #include <optional>
32
33 using namespace llvm;
34
35 namespace {
36
37 enum {
38 OPT_INVALID = 0,
39 #define OPTION(_1, _2, ID, _4, _5, _6, _7, _8, _9, _10, _11, _12) OPT_##ID,
40 #include "Options.inc"
41 #undef OPTION
42 };
43
44 #define PREFIX(NAME, VALUE) \
45 static constexpr StringLiteral NAME##_init[] = VALUE; \
46 static constexpr ArrayRef<StringLiteral> NAME(NAME##_init, \
47 std::size(NAME##_init) - 1);
48 #include "Options.inc"
49 #undef PREFIX
50
51 static constexpr opt::OptTable::Info InfoTable[] = {
52 #define OPTION(X1, X2, ID, KIND, GROUP, ALIAS, X7, X8, X9, X10, X11, X12) \
53 {X1, X2, X10, X11, OPT_##ID, opt::Option::KIND##Class, \
54 X9, X8, OPT_##GROUP, OPT_##ALIAS, X7, X12},
55 #include "Options.inc"
56 #undef OPTION
57 };
58
59 class LibOptTable : public opt::GenericOptTable {
60 public:
LibOptTable()61 LibOptTable() : opt::GenericOptTable(InfoTable, true) {}
62 };
63 }
64
getDefaultOutputPath(const NewArchiveMember & FirstMember)65 static std::string getDefaultOutputPath(const NewArchiveMember &FirstMember) {
66 SmallString<128> Val = StringRef(FirstMember.Buf->getBufferIdentifier());
67 sys::path::replace_extension(Val, ".lib");
68 return std::string(Val.str());
69 }
70
getSearchPaths(opt::InputArgList * Args,StringSaver & Saver)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 std::optional<std::string> EnvOpt = sys::Process::GetEnv("LIB");
83 if (!EnvOpt)
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
findInputFile(StringRef File,ArrayRef<StringRef> Paths)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 std::string(Path);
100 }
101 return "";
102 }
103
fatalOpenError(llvm::Error E,Twine File)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
doList(opt::InputArgList & Args)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 = MemoryBuffer::getFile(
119 Arg->getValue(), /*IsText=*/false, /*RequiresNullTerminator=*/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
getCOFFFileMachine(MemoryBufferRef MB)145 static Expected<COFF::MachineTypes> getCOFFFileMachine(MemoryBufferRef MB) {
146 std::error_code EC;
147 auto Obj = object::COFFObjectFile::create(MB);
148 if (!Obj)
149 return Obj.takeError();
150
151 uint16_t Machine = (*Obj)->getMachine();
152 if (Machine != COFF::IMAGE_FILE_MACHINE_I386 &&
153 Machine != COFF::IMAGE_FILE_MACHINE_AMD64 &&
154 Machine != COFF::IMAGE_FILE_MACHINE_ARMNT &&
155 Machine != COFF::IMAGE_FILE_MACHINE_ARM64) {
156 return createStringError(inconvertibleErrorCode(),
157 "unknown machine: " + std::to_string(Machine));
158 }
159
160 return static_cast<COFF::MachineTypes>(Machine);
161 }
162
getBitcodeFileMachine(MemoryBufferRef MB)163 static Expected<COFF::MachineTypes> getBitcodeFileMachine(MemoryBufferRef MB) {
164 Expected<std::string> TripleStr = getBitcodeTargetTriple(MB);
165 if (!TripleStr)
166 return TripleStr.takeError();
167
168 switch (Triple(*TripleStr).getArch()) {
169 case Triple::x86:
170 return COFF::IMAGE_FILE_MACHINE_I386;
171 case Triple::x86_64:
172 return COFF::IMAGE_FILE_MACHINE_AMD64;
173 case Triple::arm:
174 return COFF::IMAGE_FILE_MACHINE_ARMNT;
175 case Triple::aarch64:
176 return COFF::IMAGE_FILE_MACHINE_ARM64;
177 default:
178 return createStringError(inconvertibleErrorCode(),
179 "unknown arch in target triple: " + *TripleStr);
180 }
181 }
182
appendFile(std::vector<NewArchiveMember> & Members,COFF::MachineTypes & LibMachine,std::string & LibMachineSource,MemoryBufferRef MB)183 static void appendFile(std::vector<NewArchiveMember> &Members,
184 COFF::MachineTypes &LibMachine,
185 std::string &LibMachineSource, MemoryBufferRef MB) {
186 file_magic Magic = identify_magic(MB.getBuffer());
187
188 if (Magic != file_magic::coff_object && Magic != file_magic::bitcode &&
189 Magic != file_magic::archive && Magic != file_magic::windows_resource &&
190 Magic != file_magic::coff_import_library) {
191 llvm::errs() << MB.getBufferIdentifier()
192 << ": not a COFF object, bitcode, archive, import library or "
193 "resource file\n";
194 exit(1);
195 }
196
197 // If a user attempts to add an archive to another archive, llvm-lib doesn't
198 // handle the first archive file as a single file. Instead, it extracts all
199 // members from the archive and add them to the second archive. This behavior
200 // is for compatibility with Microsoft's lib command.
201 if (Magic == file_magic::archive) {
202 Error Err = Error::success();
203 object::Archive Archive(MB, Err);
204 fatalOpenError(std::move(Err), MB.getBufferIdentifier());
205
206 for (auto &C : Archive.children(Err)) {
207 Expected<MemoryBufferRef> ChildMB = C.getMemoryBufferRef();
208 if (!ChildMB) {
209 handleAllErrors(ChildMB.takeError(), [&](const ErrorInfoBase &EIB) {
210 llvm::errs() << MB.getBufferIdentifier() << ": " << EIB.message()
211 << "\n";
212 });
213 exit(1);
214 }
215
216 appendFile(Members, LibMachine, LibMachineSource, *ChildMB);
217 }
218
219 fatalOpenError(std::move(Err), MB.getBufferIdentifier());
220 return;
221 }
222
223 // Check that all input files have the same machine type.
224 // Mixing normal objects and LTO bitcode files is fine as long as they
225 // have the same machine type.
226 // Doing this here duplicates the header parsing work that writeArchive()
227 // below does, but it's not a lot of work and it's a bit awkward to do
228 // in writeArchive() which needs to support many tools, can't assume the
229 // input is COFF, and doesn't have a good way to report errors.
230 if (Magic == file_magic::coff_object || Magic == file_magic::bitcode) {
231 Expected<COFF::MachineTypes> MaybeFileMachine =
232 (Magic == file_magic::coff_object) ? getCOFFFileMachine(MB)
233 : getBitcodeFileMachine(MB);
234 if (!MaybeFileMachine) {
235 handleAllErrors(MaybeFileMachine.takeError(),
236 [&](const ErrorInfoBase &EIB) {
237 llvm::errs() << MB.getBufferIdentifier() << ": "
238 << EIB.message() << "\n";
239 });
240 exit(1);
241 }
242 COFF::MachineTypes FileMachine = *MaybeFileMachine;
243
244 // FIXME: Once lld-link rejects multiple resource .obj files:
245 // Call convertResToCOFF() on .res files and add the resulting
246 // COFF file to the .lib output instead of adding the .res file, and remove
247 // this check. See PR42180.
248 if (FileMachine != COFF::IMAGE_FILE_MACHINE_UNKNOWN) {
249 if (LibMachine == COFF::IMAGE_FILE_MACHINE_UNKNOWN) {
250 LibMachine = FileMachine;
251 LibMachineSource =
252 (" (inferred from earlier file '" + MB.getBufferIdentifier() + "')")
253 .str();
254 } else if (LibMachine != FileMachine) {
255 llvm::errs() << MB.getBufferIdentifier() << ": file machine type "
256 << machineToStr(FileMachine)
257 << " conflicts with library machine type "
258 << machineToStr(LibMachine) << LibMachineSource << '\n';
259 exit(1);
260 }
261 }
262 }
263
264 Members.emplace_back(MB);
265 }
266
libDriverMain(ArrayRef<const char * > ArgsArr)267 int llvm::libDriverMain(ArrayRef<const char *> ArgsArr) {
268 BumpPtrAllocator Alloc;
269 StringSaver Saver(Alloc);
270
271 // Parse command line arguments.
272 SmallVector<const char *, 20> NewArgs(ArgsArr.begin(), ArgsArr.end());
273 cl::ExpandResponseFiles(Saver, cl::TokenizeWindowsCommandLine, NewArgs);
274 ArgsArr = NewArgs;
275
276 LibOptTable Table;
277 unsigned MissingIndex;
278 unsigned MissingCount;
279 opt::InputArgList Args =
280 Table.ParseArgs(ArgsArr.slice(1), MissingIndex, MissingCount);
281 if (MissingCount) {
282 llvm::errs() << "missing arg value for \""
283 << Args.getArgString(MissingIndex) << "\", expected "
284 << MissingCount
285 << (MissingCount == 1 ? " argument.\n" : " arguments.\n");
286 return 1;
287 }
288 for (auto *Arg : Args.filtered(OPT_UNKNOWN))
289 llvm::errs() << "ignoring unknown argument: " << Arg->getAsString(Args)
290 << "\n";
291
292 // Handle /help
293 if (Args.hasArg(OPT_help)) {
294 Table.printHelp(outs(), "llvm-lib [options] file...", "LLVM Lib");
295 return 0;
296 }
297
298 // Parse /ignore:
299 llvm::StringSet<> IgnoredWarnings;
300 for (auto *Arg : Args.filtered(OPT_ignore))
301 IgnoredWarnings.insert(Arg->getValue());
302
303 // If no input files and not told otherwise, silently do nothing to match
304 // lib.exe
305 if (!Args.hasArgNoClaim(OPT_INPUT) && !Args.hasArg(OPT_llvmlibempty)) {
306 if (!IgnoredWarnings.contains("emptyoutput")) {
307 llvm::errs() << "warning: no input files, not writing output file\n";
308 llvm::errs() << " pass /llvmlibempty to write empty .lib file,\n";
309 llvm::errs() << " pass /ignore:emptyoutput to suppress warning\n";
310 if (Args.hasFlag(OPT_WX, OPT_WX_no, false)) {
311 llvm::errs() << "treating warning as error due to /WX\n";
312 return 1;
313 }
314 }
315 return 0;
316 }
317
318 if (Args.hasArg(OPT_lst)) {
319 doList(Args);
320 return 0;
321 }
322
323 std::vector<StringRef> SearchPaths = getSearchPaths(&Args, Saver);
324
325 COFF::MachineTypes LibMachine = COFF::IMAGE_FILE_MACHINE_UNKNOWN;
326 std::string LibMachineSource;
327 if (auto *Arg = Args.getLastArg(OPT_machine)) {
328 LibMachine = getMachineType(Arg->getValue());
329 if (LibMachine == COFF::IMAGE_FILE_MACHINE_UNKNOWN) {
330 llvm::errs() << "unknown /machine: arg " << Arg->getValue() << '\n';
331 return 1;
332 }
333 LibMachineSource =
334 std::string(" (from '/machine:") + Arg->getValue() + "' flag)";
335 }
336
337 std::vector<std::unique_ptr<MemoryBuffer>> MBs;
338 StringSet<> Seen;
339 std::vector<NewArchiveMember> Members;
340
341 // Create a NewArchiveMember for each input file.
342 for (auto *Arg : Args.filtered(OPT_INPUT)) {
343 // Find a file
344 std::string Path = findInputFile(Arg->getValue(), SearchPaths);
345 if (Path.empty()) {
346 llvm::errs() << Arg->getValue() << ": no such file or directory\n";
347 return 1;
348 }
349
350 // Input files are uniquified by pathname. If you specify the exact same
351 // path more than once, all but the first one are ignored.
352 //
353 // Note that there's a loophole in the rule; you can prepend `.\` or
354 // something like that to a path to make it look different, and they are
355 // handled as if they were different files. This behavior is compatible with
356 // Microsoft lib.exe.
357 if (!Seen.insert(Path).second)
358 continue;
359
360 // Open a file.
361 ErrorOr<std::unique_ptr<MemoryBuffer>> MOrErr = MemoryBuffer::getFile(
362 Path, /*IsText=*/false, /*RequiresNullTerminator=*/false);
363 fatalOpenError(errorCodeToError(MOrErr.getError()), Path);
364 MemoryBufferRef MBRef = (*MOrErr)->getMemBufferRef();
365
366 // Append a file.
367 appendFile(Members, LibMachine, LibMachineSource, MBRef);
368
369 // Take the ownership of the file buffer to keep the file open.
370 MBs.push_back(std::move(*MOrErr));
371 }
372
373 // Create an archive file.
374 std::string OutputPath;
375 if (auto *Arg = Args.getLastArg(OPT_out)) {
376 OutputPath = Arg->getValue();
377 } else if (!Members.empty()) {
378 OutputPath = getDefaultOutputPath(Members[0]);
379 } else {
380 llvm::errs() << "no output path given, and cannot infer with no inputs\n";
381 return 1;
382 }
383 // llvm-lib uses relative paths for both regular and thin archives, unlike
384 // standard GNU ar, which only uses relative paths for thin archives and
385 // basenames for regular archives.
386 for (NewArchiveMember &Member : Members) {
387 if (sys::path::is_relative(Member.MemberName)) {
388 Expected<std::string> PathOrErr =
389 computeArchiveRelativePath(OutputPath, Member.MemberName);
390 if (PathOrErr)
391 Member.MemberName = Saver.save(*PathOrErr);
392 }
393 }
394
395 if (Error E =
396 writeArchive(OutputPath, Members,
397 /*WriteSymtab=*/true, object::Archive::K_GNU,
398 /*Deterministic*/ true, Args.hasArg(OPT_llvmlibthin))) {
399 handleAllErrors(std::move(E), [&](const ErrorInfoBase &EI) {
400 llvm::errs() << OutputPath << ": " << EI.message() << "\n";
401 });
402 return 1;
403 }
404
405 return 0;
406 }
407