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