xref: /llvm-project/llvm/tools/llvm-objcopy/llvm-objcopy.cpp (revision 021de7cf80268091cf13485a538b611b37d0b33e)
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) {
62   if (OutputFileName == "-")
63     return Write(outs());
64 
65   if (OutputFileName == "/dev/null") {
66     raw_null_ostream Out;
67     return Write(Out);
68   }
69 
70   unsigned Mode = sys::fs::all_read | sys::fs::all_write | sys::fs::all_exe;
71   Expected<sys::fs::TempFile> Temp =
72       sys::fs::TempFile::create(OutputFileName + ".temp-objcopy-%%%%%%", Mode);
73   if (!Temp)
74     return createFileError(OutputFileName, Temp.takeError());
75 
76   raw_fd_ostream Out(Temp->FD, false);
77 
78   if (Error E = Write(Out)) {
79     if (Error DiscardError = Temp->discard())
80       return joinErrors(std::move(E), std::move(DiscardError));
81     return E;
82   }
83   Out.flush();
84 
85   return Temp->keep(OutputFileName);
86 }
87 
88 // The name this program was invoked as.
89 StringRef ToolName;
90 
91 ErrorSuccess reportWarning(Error E) {
92   assert(E);
93   WithColor::warning(errs(), ToolName) << toString(std::move(E)) << '\n';
94   return Error::success();
95 }
96 
97 static Expected<DriverConfig> getDriverConfig(ArrayRef<const char *> Args) {
98   StringRef Stem = sys::path::stem(ToolName);
99   auto Is = [=](StringRef Tool) {
100     // We need to recognize the following filenames:
101     //
102     // llvm-objcopy -> objcopy
103     // strip-10.exe -> strip
104     // powerpc64-unknown-freebsd13-objcopy -> objcopy
105     // llvm-install-name-tool -> install-name-tool
106     auto I = Stem.rfind_lower(Tool);
107     return I != StringRef::npos &&
108            (I + Tool.size() == Stem.size() || !isAlnum(Stem[I + Tool.size()]));
109   };
110 
111   if (Is("bitcode-strip") || Is("bitcode_strip"))
112     return parseBitcodeStripOptions(Args);
113   else if (Is("strip"))
114     return parseStripOptions(Args, reportWarning);
115   else if (Is("install-name-tool") || Is("install_name_tool"))
116     return parseInstallNameToolOptions(Args);
117   else
118     return parseObjcopyOptions(Args, reportWarning);
119 }
120 
121 } // end namespace objcopy
122 } // end namespace llvm
123 
124 using namespace llvm;
125 using namespace llvm::object;
126 using namespace llvm::objcopy;
127 
128 // For regular archives this function simply calls llvm::writeArchive,
129 // For thin archives it writes the archive file itself as well as its members.
130 static Error deepWriteArchive(StringRef ArcName,
131                               ArrayRef<NewArchiveMember> NewMembers,
132                               bool WriteSymtab, object::Archive::Kind Kind,
133                               bool Deterministic, bool Thin) {
134   if (Error E = writeArchive(ArcName, NewMembers, WriteSymtab, Kind,
135                              Deterministic, Thin))
136     return createFileError(ArcName, std::move(E));
137 
138   if (!Thin)
139     return Error::success();
140 
141   for (const NewArchiveMember &Member : NewMembers) {
142     // For regular files (as is the case for deepWriteArchive),
143     // FileOutputBuffer::create will return OnDiskBuffer.
144     // OnDiskBuffer uses a temporary file and then renames it. So in reality
145     // there is no inefficiency / duplicated in-memory buffers in this case. For
146     // now in-memory buffers can not be completely avoided since
147     // NewArchiveMember still requires them even though writeArchive does not
148     // write them on disk.
149     Expected<std::unique_ptr<FileOutputBuffer>> FB =
150         FileOutputBuffer::create(Member.MemberName, Member.Buf->getBufferSize(),
151                                  FileOutputBuffer::F_executable);
152     if (!FB)
153       return FB.takeError();
154     std::copy(Member.Buf->getBufferStart(), Member.Buf->getBufferEnd(),
155               (*FB)->getBufferStart());
156     if (Error E = (*FB)->commit())
157       return E;
158   }
159   return Error::success();
160 }
161 
162 /// The function executeObjcopyOnIHex does the dispatch based on the format
163 /// of the output specified by the command line options.
164 static Error executeObjcopyOnIHex(CopyConfig &Config, MemoryBuffer &In,
165                                   raw_ostream &Out) {
166   // TODO: support output formats other than ELF.
167   if (Error E = Config.parseELFConfig())
168     return E;
169   return elf::executeObjcopyOnIHex(Config, In, Out);
170 }
171 
172 /// The function executeObjcopyOnRawBinary does the dispatch based on the format
173 /// of the output specified by the command line options.
174 static Error executeObjcopyOnRawBinary(CopyConfig &Config, MemoryBuffer &In,
175                                        raw_ostream &Out) {
176   switch (Config.OutputFormat) {
177   case FileFormat::ELF:
178   // FIXME: Currently, we call elf::executeObjcopyOnRawBinary even if the
179   // output format is binary/ihex or it's not given. This behavior differs from
180   // GNU objcopy. See https://bugs.llvm.org/show_bug.cgi?id=42171 for details.
181   case FileFormat::Binary:
182   case FileFormat::IHex:
183   case FileFormat::Unspecified:
184     if (Error E = Config.parseELFConfig())
185       return E;
186     return elf::executeObjcopyOnRawBinary(Config, In, Out);
187   }
188 
189   llvm_unreachable("unsupported output format");
190 }
191 
192 /// The function executeObjcopyOnBinary does the dispatch based on the format
193 /// of the input binary (ELF, MachO or COFF).
194 static Error executeObjcopyOnBinary(CopyConfig &Config, object::Binary &In,
195                                     raw_ostream &Out) {
196   if (auto *ELFBinary = dyn_cast<object::ELFObjectFileBase>(&In)) {
197     if (Error E = Config.parseELFConfig())
198       return E;
199     return elf::executeObjcopyOnBinary(Config, *ELFBinary, Out);
200   } else if (auto *COFFBinary = dyn_cast<object::COFFObjectFile>(&In))
201     return coff::executeObjcopyOnBinary(Config, *COFFBinary, Out);
202   else if (auto *MachOBinary = dyn_cast<object::MachOObjectFile>(&In))
203     return macho::executeObjcopyOnBinary(Config, *MachOBinary, Out);
204   else if (auto *MachOUniversalBinary =
205                dyn_cast<object::MachOUniversalBinary>(&In))
206     return macho::executeObjcopyOnMachOUniversalBinary(
207         Config, *MachOUniversalBinary, Out);
208   else if (auto *WasmBinary = dyn_cast<object::WasmObjectFile>(&In))
209     return objcopy::wasm::executeObjcopyOnBinary(Config, *WasmBinary, Out);
210   else
211     return createStringError(object_error::invalid_file_type,
212                              "unsupported object file format");
213 }
214 
215 namespace llvm {
216 namespace objcopy {
217 
218 Expected<std::vector<NewArchiveMember>>
219 createNewArchiveMembers(CopyConfig &Config, const Archive &Ar) {
220   std::vector<NewArchiveMember> NewArchiveMembers;
221   Error Err = Error::success();
222   for (const Archive::Child &Child : Ar.children(Err)) {
223     Expected<StringRef> ChildNameOrErr = Child.getName();
224     if (!ChildNameOrErr)
225       return createFileError(Ar.getFileName(), ChildNameOrErr.takeError());
226 
227     Expected<std::unique_ptr<Binary>> ChildOrErr = Child.getAsBinary();
228     if (!ChildOrErr)
229       return createFileError(Ar.getFileName() + "(" + *ChildNameOrErr + ")",
230                              ChildOrErr.takeError());
231 
232     SmallVector<char, 0> Buffer;
233     raw_svector_ostream MemStream(Buffer);
234 
235     if (Error E = executeObjcopyOnBinary(Config, *ChildOrErr->get(), MemStream))
236       return std::move(E);
237 
238     Expected<NewArchiveMember> Member =
239         NewArchiveMember::getOldMember(Child, Config.DeterministicArchives);
240     if (!Member)
241       return createFileError(Ar.getFileName(), Member.takeError());
242 
243     Member->Buf = std::make_unique<SmallVectorMemoryBuffer>(
244         std::move(Buffer), ChildNameOrErr.get());
245     Member->MemberName = Member->Buf->getBufferIdentifier();
246     NewArchiveMembers.push_back(std::move(*Member));
247   }
248   if (Err)
249     return createFileError(Config.InputFilename, std::move(Err));
250   return std::move(NewArchiveMembers);
251 }
252 
253 } // end namespace objcopy
254 } // end namespace llvm
255 
256 static Error executeObjcopyOnArchive(CopyConfig &Config,
257                                      const object::Archive &Ar) {
258   Expected<std::vector<NewArchiveMember>> NewArchiveMembersOrErr =
259       createNewArchiveMembers(Config, Ar);
260   if (!NewArchiveMembersOrErr)
261     return NewArchiveMembersOrErr.takeError();
262   return deepWriteArchive(Config.OutputFilename, *NewArchiveMembersOrErr,
263                           Ar.hasSymbolTable(), Ar.kind(),
264                           Config.DeterministicArchives, Ar.isThin());
265 }
266 
267 static Error restoreStatOnFile(StringRef Filename,
268                                const sys::fs::file_status &Stat,
269                                const CopyConfig &Config) {
270   int FD;
271 
272   // Writing to stdout should not be treated as an error here, just
273   // do not set access/modification times or permissions.
274   if (Filename == "-")
275     return Error::success();
276 
277   if (auto EC =
278           sys::fs::openFileForWrite(Filename, FD, sys::fs::CD_OpenExisting))
279     return createFileError(Filename, EC);
280 
281   if (Config.PreserveDates)
282     if (auto EC = sys::fs::setLastAccessAndModificationTime(
283             FD, Stat.getLastAccessedTime(), Stat.getLastModificationTime()))
284       return createFileError(Filename, EC);
285 
286   sys::fs::file_status OStat;
287   if (std::error_code EC = sys::fs::status(FD, OStat))
288     return createFileError(Filename, EC);
289   if (OStat.type() == sys::fs::file_type::regular_file) {
290     sys::fs::perms Perm = Stat.permissions();
291     if (Config.InputFilename != Config.OutputFilename)
292       Perm = static_cast<sys::fs::perms>(Perm & ~sys::fs::getUmask() & ~06000);
293 #ifdef _WIN32
294     if (auto EC = sys::fs::setPermissions(Filename, Perm))
295 #else
296     if (auto EC = sys::fs::setPermissions(FD, Perm))
297 #endif
298       return createFileError(Filename, EC);
299 
300 #ifndef _WIN32
301     // Keep ownership if llvm-objcopy is called under root.
302     if (Config.InputFilename == Config.OutputFilename && OStat.getUser() == 0)
303       sys::fs::changeFileOwnership(FD, Stat.getUser(), Stat.getGroup());
304 #endif
305   }
306 
307   if (auto EC = sys::Process::SafelyCloseFileDescriptor(FD))
308     return createFileError(Filename, EC);
309 
310   return Error::success();
311 }
312 
313 /// The function executeObjcopy does the higher level dispatch based on the type
314 /// of input (raw binary, archive or single object file) and takes care of the
315 /// format-agnostic modifications, i.e. preserving dates.
316 static Error executeObjcopy(CopyConfig &Config) {
317   sys::fs::file_status Stat;
318   if (Config.InputFilename != "-") {
319     if (auto EC = sys::fs::status(Config.InputFilename, Stat))
320       return createFileError(Config.InputFilename, EC);
321   } else {
322     Stat.permissions(static_cast<sys::fs::perms>(0777));
323   }
324 
325   using ProcessRawFn = Error (*)(CopyConfig &, MemoryBuffer &, raw_ostream &);
326   ProcessRawFn ProcessRaw;
327   switch (Config.InputFormat) {
328   case FileFormat::Binary:
329     ProcessRaw = executeObjcopyOnRawBinary;
330     break;
331   case FileFormat::IHex:
332     ProcessRaw = executeObjcopyOnIHex;
333     break;
334   default:
335     ProcessRaw = nullptr;
336   }
337 
338   if (ProcessRaw) {
339     auto BufOrErr = MemoryBuffer::getFileOrSTDIN(Config.InputFilename);
340     if (!BufOrErr)
341       return createFileError(Config.InputFilename, BufOrErr.getError());
342 
343     if (Error E = writeToFile(
344             Config.OutputFilename, [&](raw_ostream &OutFile) -> Error {
345               return ProcessRaw(Config, *BufOrErr->get(), OutFile);
346             }))
347       return E;
348   } else {
349     Expected<OwningBinary<llvm::object::Binary>> BinaryOrErr =
350         createBinary(Config.InputFilename);
351     if (!BinaryOrErr)
352       return createFileError(Config.InputFilename, BinaryOrErr.takeError());
353 
354     if (Archive *Ar = dyn_cast<Archive>(BinaryOrErr.get().getBinary())) {
355       if (Error E = executeObjcopyOnArchive(Config, *Ar))
356         return E;
357     } else {
358       if (Error E = writeToFile(
359               Config.OutputFilename, [&](raw_ostream &OutFile) -> Error {
360                 return executeObjcopyOnBinary(
361                     Config, *BinaryOrErr.get().getBinary(), OutFile);
362               }))
363         return E;
364     }
365   }
366 
367   if (Error E = restoreStatOnFile(Config.OutputFilename, Stat, Config))
368     return E;
369 
370   if (!Config.SplitDWO.empty()) {
371     Stat.permissions(static_cast<sys::fs::perms>(0666));
372     if (Error E = restoreStatOnFile(Config.SplitDWO, Stat, Config))
373       return E;
374   }
375 
376   return Error::success();
377 }
378 
379 namespace {
380 
381 } // anonymous namespace
382 
383 int main(int argc, char **argv) {
384   InitLLVM X(argc, argv);
385   ToolName = argv[0];
386 
387   // Expand response files.
388   // TODO: Move these lines, which are copied from lib/Support/CommandLine.cpp,
389   // into a separate function in the CommandLine library and call that function
390   // here. This is duplicated code.
391   SmallVector<const char *, 20> NewArgv(argv, argv + argc);
392   BumpPtrAllocator A;
393   StringSaver Saver(A);
394   cl::ExpandResponseFiles(Saver,
395                           Triple(sys::getProcessTriple()).isOSWindows()
396                               ? cl::TokenizeWindowsCommandLine
397                               : cl::TokenizeGNUCommandLine,
398                           NewArgv);
399 
400   auto Args = makeArrayRef(NewArgv).drop_front();
401   Expected<DriverConfig> DriverConfig = getDriverConfig(Args);
402 
403   if (!DriverConfig) {
404     logAllUnhandledErrors(DriverConfig.takeError(),
405                           WithColor::error(errs(), ToolName));
406     return 1;
407   }
408   for (CopyConfig &CopyConfig : DriverConfig->CopyConfigs) {
409     if (Error E = executeObjcopy(CopyConfig)) {
410       logAllUnhandledErrors(std::move(E), WithColor::error(errs(), ToolName));
411       return 1;
412     }
413   }
414 
415   return 0;
416 }
417