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