xref: /llvm-project/llvm/tools/llvm-objcopy/llvm-objcopy.cpp (revision 4f16e177e104eb80589311dc3cc1b5355a7e41bb)
1 //===- llvm-objcopy.cpp ---------------------------------------------------===//
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 #include "llvm-objcopy.h"
10 #include "COFF/COFFObjcopy.h"
11 #include "CopyConfig.h"
12 #include "ELF/ELFObjcopy.h"
13 #include "MachO/MachOObjcopy.h"
14 #include "wasm/WasmObjcopy.h"
15 
16 #include "llvm/ADT/STLExtras.h"
17 #include "llvm/ADT/SmallVector.h"
18 #include "llvm/ADT/StringRef.h"
19 #include "llvm/ADT/Twine.h"
20 #include "llvm/BinaryFormat/ELF.h"
21 #include "llvm/Object/Archive.h"
22 #include "llvm/Object/ArchiveWriter.h"
23 #include "llvm/Object/Binary.h"
24 #include "llvm/Object/COFF.h"
25 #include "llvm/Object/ELFObjectFile.h"
26 #include "llvm/Object/ELFTypes.h"
27 #include "llvm/Object/Error.h"
28 #include "llvm/Object/MachO.h"
29 #include "llvm/Object/MachOUniversal.h"
30 #include "llvm/Object/Wasm.h"
31 #include "llvm/Option/Arg.h"
32 #include "llvm/Option/ArgList.h"
33 #include "llvm/Option/Option.h"
34 #include "llvm/Support/Casting.h"
35 #include "llvm/Support/CommandLine.h"
36 #include "llvm/Support/Errc.h"
37 #include "llvm/Support/Error.h"
38 #include "llvm/Support/ErrorHandling.h"
39 #include "llvm/Support/ErrorOr.h"
40 #include "llvm/Support/Host.h"
41 #include "llvm/Support/InitLLVM.h"
42 #include "llvm/Support/Memory.h"
43 #include "llvm/Support/Path.h"
44 #include "llvm/Support/Process.h"
45 #include "llvm/Support/SmallVectorMemoryBuffer.h"
46 #include "llvm/Support/StringSaver.h"
47 #include "llvm/Support/WithColor.h"
48 #include "llvm/Support/raw_ostream.h"
49 #include <algorithm>
50 #include <cassert>
51 #include <cstdlib>
52 #include <memory>
53 #include <string>
54 #include <system_error>
55 #include <utility>
56 
57 namespace llvm {
58 namespace objcopy {
59 
60 Error writeToFile(StringRef OutputFileName,
61                   std::function<Error(raw_ostream &)> Write, bool KeepOwnership,
62                   unsigned UserID, unsigned GroupID) {
63   if (OutputFileName == "-")
64     return Write(outs());
65 
66   if (OutputFileName == "/dev/null") {
67     raw_null_ostream Out;
68     return Write(Out);
69   }
70 
71   unsigned Mode = sys::fs::all_read | sys::fs::all_write | sys::fs::all_exe;
72   Expected<sys::fs::TempFile> Temp =
73       sys::fs::TempFile::create(OutputFileName + ".temp-objcopy-%%%%%%", Mode);
74   if (!Temp)
75     return createFileError(OutputFileName, Temp.takeError());
76 
77 #ifndef _WIN32
78   // Try to preserve file ownership if requested.
79   if (KeepOwnership) {
80     sys::fs::file_status Stat;
81     if (!sys::fs::status(Temp->FD, Stat) && Stat.getUser() == 0)
82       sys::fs::changeFileOwnership(Temp->FD, UserID, GroupID);
83   }
84 #endif
85 
86   raw_fd_ostream Out(Temp->FD, false);
87 
88   if (Error E = Write(Out)) {
89     if (Error DiscardError = Temp->discard())
90       return joinErrors(std::move(E), std::move(DiscardError));
91     return E;
92   }
93   Out.flush();
94 
95   return Temp->keep(OutputFileName);
96 }
97 
98 // The name this program was invoked as.
99 StringRef ToolName;
100 
101 ErrorSuccess reportWarning(Error E) {
102   assert(E);
103   WithColor::warning(errs(), ToolName) << toString(std::move(E)) << '\n';
104   return Error::success();
105 }
106 
107 static Expected<DriverConfig> getDriverConfig(ArrayRef<const char *> Args) {
108   StringRef Stem = sys::path::stem(ToolName);
109   auto Is = [=](StringRef Tool) {
110     // We need to recognize the following filenames:
111     //
112     // llvm-objcopy -> objcopy
113     // strip-10.exe -> strip
114     // powerpc64-unknown-freebsd13-objcopy -> objcopy
115     // llvm-install-name-tool -> install-name-tool
116     auto I = Stem.rfind_lower(Tool);
117     return I != StringRef::npos &&
118            (I + Tool.size() == Stem.size() || !isAlnum(Stem[I + Tool.size()]));
119   };
120 
121   if (Is("bitcode-strip") || Is("bitcode_strip"))
122     return parseBitcodeStripOptions(Args);
123   else if (Is("strip"))
124     return parseStripOptions(Args, reportWarning);
125   else if (Is("install-name-tool") || Is("install_name_tool"))
126     return parseInstallNameToolOptions(Args);
127   else
128     return parseObjcopyOptions(Args, reportWarning);
129 }
130 
131 } // end namespace objcopy
132 } // end namespace llvm
133 
134 using namespace llvm;
135 using namespace llvm::object;
136 using namespace llvm::objcopy;
137 
138 // For regular archives this function simply calls llvm::writeArchive,
139 // For thin archives it writes the archive file itself as well as its members.
140 static Error deepWriteArchive(StringRef ArcName,
141                               ArrayRef<NewArchiveMember> NewMembers,
142                               bool WriteSymtab, object::Archive::Kind Kind,
143                               bool Deterministic, bool Thin) {
144   if (Error E = writeArchive(ArcName, NewMembers, WriteSymtab, Kind,
145                              Deterministic, Thin))
146     return createFileError(ArcName, std::move(E));
147 
148   if (!Thin)
149     return Error::success();
150 
151   for (const NewArchiveMember &Member : NewMembers) {
152     // For regular files (as is the case for deepWriteArchive),
153     // FileOutputBuffer::create will return OnDiskBuffer.
154     // OnDiskBuffer uses a temporary file and then renames it. So in reality
155     // there is no inefficiency / duplicated in-memory buffers in this case. For
156     // now in-memory buffers can not be completely avoided since
157     // NewArchiveMember still requires them even though writeArchive does not
158     // write them on disk.
159     Expected<std::unique_ptr<FileOutputBuffer>> FB = FileOutputBuffer::create(
160         Member.MemberName, Member.Buf->getBufferSize(),
161         FileOutputBuffer::F_executable | FileOutputBuffer::F_keep_ownership);
162     if (!FB)
163       return FB.takeError();
164     std::copy(Member.Buf->getBufferStart(), Member.Buf->getBufferEnd(),
165               (*FB)->getBufferStart());
166     if (Error E = (*FB)->commit())
167       return E;
168   }
169   return Error::success();
170 }
171 
172 /// The function executeObjcopyOnIHex does the dispatch based on the format
173 /// of the output specified by the command line options.
174 static Error executeObjcopyOnIHex(CopyConfig &Config, MemoryBuffer &In,
175                                   raw_ostream &Out) {
176   // TODO: support output formats other than ELF.
177   if (Error E = Config.parseELFConfig())
178     return E;
179   return elf::executeObjcopyOnIHex(Config, In, Out);
180 }
181 
182 /// The function executeObjcopyOnRawBinary does the dispatch based on the format
183 /// of the output specified by the command line options.
184 static Error executeObjcopyOnRawBinary(CopyConfig &Config, MemoryBuffer &In,
185                                        raw_ostream &Out) {
186   switch (Config.OutputFormat) {
187   case FileFormat::ELF:
188   // FIXME: Currently, we call elf::executeObjcopyOnRawBinary even if the
189   // output format is binary/ihex or it's not given. This behavior differs from
190   // GNU objcopy. See https://bugs.llvm.org/show_bug.cgi?id=42171 for details.
191   case FileFormat::Binary:
192   case FileFormat::IHex:
193   case FileFormat::Unspecified:
194     if (Error E = Config.parseELFConfig())
195       return E;
196     return elf::executeObjcopyOnRawBinary(Config, In, Out);
197   }
198 
199   llvm_unreachable("unsupported output format");
200 }
201 
202 /// The function executeObjcopyOnBinary does the dispatch based on the format
203 /// of the input binary (ELF, MachO or COFF).
204 static Error executeObjcopyOnBinary(CopyConfig &Config, object::Binary &In,
205                                     raw_ostream &Out) {
206   if (auto *ELFBinary = dyn_cast<object::ELFObjectFileBase>(&In)) {
207     if (Error E = Config.parseELFConfig())
208       return E;
209     return elf::executeObjcopyOnBinary(Config, *ELFBinary, Out);
210   } else if (auto *COFFBinary = dyn_cast<object::COFFObjectFile>(&In))
211     return coff::executeObjcopyOnBinary(Config, *COFFBinary, Out);
212   else if (auto *MachOBinary = dyn_cast<object::MachOObjectFile>(&In))
213     return macho::executeObjcopyOnBinary(Config, *MachOBinary, Out);
214   else if (auto *MachOUniversalBinary =
215                dyn_cast<object::MachOUniversalBinary>(&In))
216     return macho::executeObjcopyOnMachOUniversalBinary(
217         Config, *MachOUniversalBinary, Out);
218   else if (auto *WasmBinary = dyn_cast<object::WasmObjectFile>(&In))
219     return objcopy::wasm::executeObjcopyOnBinary(Config, *WasmBinary, Out);
220   else
221     return createStringError(object_error::invalid_file_type,
222                              "unsupported object file format");
223 }
224 
225 namespace llvm {
226 namespace objcopy {
227 
228 Expected<std::vector<NewArchiveMember>>
229 createNewArchiveMembers(CopyConfig &Config, const Archive &Ar) {
230   std::vector<NewArchiveMember> NewArchiveMembers;
231   Error Err = Error::success();
232   for (const Archive::Child &Child : Ar.children(Err)) {
233     Expected<StringRef> ChildNameOrErr = Child.getName();
234     if (!ChildNameOrErr)
235       return createFileError(Ar.getFileName(), ChildNameOrErr.takeError());
236 
237     Expected<std::unique_ptr<Binary>> ChildOrErr = Child.getAsBinary();
238     if (!ChildOrErr)
239       return createFileError(Ar.getFileName() + "(" + *ChildNameOrErr + ")",
240                              ChildOrErr.takeError());
241 
242     SmallVector<char, 0> Buffer;
243     raw_svector_ostream MemStream(Buffer);
244 
245     if (Error E = executeObjcopyOnBinary(Config, *ChildOrErr->get(), MemStream))
246       return std::move(E);
247 
248     Expected<NewArchiveMember> Member =
249         NewArchiveMember::getOldMember(Child, Config.DeterministicArchives);
250     if (!Member)
251       return createFileError(Ar.getFileName(), Member.takeError());
252 
253     Member->Buf = std::make_unique<SmallVectorMemoryBuffer>(
254         std::move(Buffer), ChildNameOrErr.get());
255     Member->MemberName = Member->Buf->getBufferIdentifier();
256     NewArchiveMembers.push_back(std::move(*Member));
257   }
258   if (Err)
259     return createFileError(Config.InputFilename, std::move(Err));
260   return std::move(NewArchiveMembers);
261 }
262 
263 } // end namespace objcopy
264 } // end namespace llvm
265 
266 static Error executeObjcopyOnArchive(CopyConfig &Config,
267                                      const object::Archive &Ar) {
268   Expected<std::vector<NewArchiveMember>> NewArchiveMembersOrErr =
269       createNewArchiveMembers(Config, Ar);
270   if (!NewArchiveMembersOrErr)
271     return NewArchiveMembersOrErr.takeError();
272   return deepWriteArchive(Config.OutputFilename, *NewArchiveMembersOrErr,
273                           Ar.hasSymbolTable(), Ar.kind(),
274                           Config.DeterministicArchives, Ar.isThin());
275 }
276 
277 static Error restoreStatOnFile(StringRef Filename,
278                                const sys::fs::file_status &Stat,
279                                const CopyConfig &Config) {
280   int FD;
281 
282   // Writing to stdout should not be treated as an error here, just
283   // do not set access/modification times or permissions.
284   if (Filename == "-")
285     return Error::success();
286 
287   if (auto EC =
288           sys::fs::openFileForWrite(Filename, FD, sys::fs::CD_OpenExisting))
289     return createFileError(Filename, EC);
290 
291   if (Config.PreserveDates)
292     if (auto EC = sys::fs::setLastAccessAndModificationTime(
293             FD, Stat.getLastAccessedTime(), Stat.getLastModificationTime()))
294       return createFileError(Filename, EC);
295 
296   sys::fs::file_status OStat;
297   if (std::error_code EC = sys::fs::status(FD, OStat))
298     return createFileError(Filename, EC);
299   if (OStat.type() == sys::fs::file_type::regular_file) {
300     sys::fs::perms Perm = Stat.permissions();
301     if (Config.InputFilename != Config.OutputFilename)
302       Perm = static_cast<sys::fs::perms>(Perm & ~sys::fs::getUmask() & ~06000);
303 #ifdef _WIN32
304     if (auto EC = sys::fs::setPermissions(Filename, Perm))
305 #else
306     if (auto EC = sys::fs::setPermissions(FD, Perm))
307 #endif
308       return createFileError(Filename, EC);
309   }
310 
311   if (auto EC = sys::Process::SafelyCloseFileDescriptor(FD))
312     return createFileError(Filename, EC);
313 
314   return Error::success();
315 }
316 
317 /// The function executeObjcopy does the higher level dispatch based on the type
318 /// of input (raw binary, archive or single object file) and takes care of the
319 /// format-agnostic modifications, i.e. preserving dates.
320 static Error executeObjcopy(CopyConfig &Config) {
321   sys::fs::file_status Stat;
322   if (Config.InputFilename != "-") {
323     if (auto EC = sys::fs::status(Config.InputFilename, Stat))
324       return createFileError(Config.InputFilename, EC);
325   } else {
326     Stat.permissions(static_cast<sys::fs::perms>(0777));
327   }
328 
329   using ProcessRawFn = Error (*)(CopyConfig &, MemoryBuffer &, raw_ostream &);
330   ProcessRawFn ProcessRaw;
331   switch (Config.InputFormat) {
332   case FileFormat::Binary:
333     ProcessRaw = executeObjcopyOnRawBinary;
334     break;
335   case FileFormat::IHex:
336     ProcessRaw = executeObjcopyOnIHex;
337     break;
338   default:
339     ProcessRaw = nullptr;
340   }
341 
342   if (ProcessRaw) {
343     auto BufOrErr = MemoryBuffer::getFileOrSTDIN(Config.InputFilename);
344     if (!BufOrErr)
345       return createFileError(Config.InputFilename, BufOrErr.getError());
346 
347     if (Error E = writeToFile(
348             Config.OutputFilename, [&](raw_ostream &OutFile) -> Error {
349               return ProcessRaw(Config, *BufOrErr->get(), OutFile);
350             }))
351       return E;
352   } else {
353     Expected<OwningBinary<llvm::object::Binary>> BinaryOrErr =
354         createBinary(Config.InputFilename);
355     if (!BinaryOrErr)
356       return createFileError(Config.InputFilename, BinaryOrErr.takeError());
357 
358     if (Archive *Ar = dyn_cast<Archive>(BinaryOrErr.get().getBinary())) {
359       if (Error E = executeObjcopyOnArchive(Config, *Ar))
360         return E;
361     } else {
362       if (Error E = writeToFile(
363               Config.OutputFilename,
364               [&](raw_ostream &OutFile) -> Error {
365                 return executeObjcopyOnBinary(
366                     Config, *BinaryOrErr.get().getBinary(), OutFile);
367               },
368               Config.InputFilename != "-" &&
369                   Config.InputFilename == Config.OutputFilename,
370               Stat.getUser(), Stat.getGroup()))
371         return E;
372     }
373   }
374 
375   if (Error E = restoreStatOnFile(Config.OutputFilename, Stat, Config))
376     return E;
377 
378   if (!Config.SplitDWO.empty()) {
379     Stat.permissions(static_cast<sys::fs::perms>(0666));
380     if (Error E = restoreStatOnFile(Config.SplitDWO, Stat, Config))
381       return E;
382   }
383 
384   return Error::success();
385 }
386 
387 namespace {
388 
389 } // anonymous namespace
390 
391 int main(int argc, char **argv) {
392   InitLLVM X(argc, argv);
393   ToolName = argv[0];
394 
395   // Expand response files.
396   // TODO: Move these lines, which are copied from lib/Support/CommandLine.cpp,
397   // into a separate function in the CommandLine library and call that function
398   // here. This is duplicated code.
399   SmallVector<const char *, 20> NewArgv(argv, argv + argc);
400   BumpPtrAllocator A;
401   StringSaver Saver(A);
402   cl::ExpandResponseFiles(Saver,
403                           Triple(sys::getProcessTriple()).isOSWindows()
404                               ? cl::TokenizeWindowsCommandLine
405                               : cl::TokenizeGNUCommandLine,
406                           NewArgv);
407 
408   auto Args = makeArrayRef(NewArgv).drop_front();
409   Expected<DriverConfig> DriverConfig = getDriverConfig(Args);
410 
411   if (!DriverConfig) {
412     logAllUnhandledErrors(DriverConfig.takeError(),
413                           WithColor::error(errs(), ToolName));
414     return 1;
415   }
416   for (CopyConfig &CopyConfig : DriverConfig->CopyConfigs) {
417     if (Error E = executeObjcopy(CopyConfig)) {
418       logAllUnhandledErrors(std::move(E), WithColor::error(errs(), ToolName));
419       return 1;
420     }
421   }
422 
423   return 0;
424 }
425