xref: /llvm-project/llvm/tools/llvm-objcopy/llvm-objcopy.cpp (revision c45fd0cad428f531c30f0629852aab2fcebe7b47) 
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 
57 LLVM_ATTRIBUTE_NORETURN void error(Twine Message) {
58   WithColor::error(errs(), ToolName) << Message << "\n";
59   exit(1);
60 }
61 
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 
72 LLVM_ATTRIBUTE_NORETURN void reportError(StringRef File, std::error_code EC) {
73   assert(EC);
74   error(createFileError(File, EC));
75 }
76 
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 
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.
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.
135 static Error executeObjcopyOnIHex(const CopyConfig &Config, MemoryBuffer &In,
136                                   Buffer &Out) {
137   // TODO: support output formats other than ELF.
138   return elf::executeObjcopyOnIHex(Config, In, Out);
139 }
140 
141 /// The function executeObjcopyOnRawBinary does the dispatch based on the format
142 /// of the output specified by the command line options.
143 static Error executeObjcopyOnRawBinary(const CopyConfig &Config,
144                                        MemoryBuffer &In, Buffer &Out) {
145   switch (Config.OutputFormat) {
146   case FileFormat::ELF:
147   // FIXME: Currently, we call elf::executeObjcopyOnRawBinary even if the
148   // output format is binary/ihex or it's not given. This behavior differs from
149   // GNU objcopy. See https://bugs.llvm.org/show_bug.cgi?id=42171 for details.
150   case FileFormat::Binary:
151   case FileFormat::IHex:
152   case FileFormat::Unspecified:
153     return elf::executeObjcopyOnRawBinary(Config, In, Out);
154   }
155 
156   llvm_unreachable("unsupported output format");
157 }
158 
159 /// The function executeObjcopyOnBinary does the dispatch based on the format
160 /// of the input binary (ELF, MachO or COFF).
161 static Error executeObjcopyOnBinary(const CopyConfig &Config,
162                                     object::Binary &In, Buffer &Out) {
163   if (auto *ELFBinary = dyn_cast<object::ELFObjectFileBase>(&In))
164     return elf::executeObjcopyOnBinary(Config, *ELFBinary, Out);
165   else if (auto *COFFBinary = dyn_cast<object::COFFObjectFile>(&In))
166     return coff::executeObjcopyOnBinary(Config, *COFFBinary, Out);
167   else if (auto *MachOBinary = dyn_cast<object::MachOObjectFile>(&In))
168     return macho::executeObjcopyOnBinary(Config, *MachOBinary, Out);
169   else
170     return createStringError(object_error::invalid_file_type,
171                              "unsupported object file format");
172 }
173 
174 static Error executeObjcopyOnArchive(const CopyConfig &Config,
175                                      const Archive &Ar) {
176   std::vector<NewArchiveMember> NewArchiveMembers;
177   Error Err = Error::success();
178   for (const Archive::Child &Child : Ar.children(Err)) {
179     Expected<StringRef> ChildNameOrErr = Child.getName();
180     if (!ChildNameOrErr)
181       return createFileError(Ar.getFileName(), ChildNameOrErr.takeError());
182 
183     Expected<std::unique_ptr<Binary>> ChildOrErr = Child.getAsBinary();
184     if (!ChildOrErr)
185       return createFileError(Ar.getFileName() + "(" + *ChildNameOrErr + ")",
186                              ChildOrErr.takeError());
187 
188     MemBuffer MB(ChildNameOrErr.get());
189     if (Error E = executeObjcopyOnBinary(Config, *ChildOrErr->get(), MB))
190       return E;
191 
192     Expected<NewArchiveMember> Member =
193         NewArchiveMember::getOldMember(Child, Config.DeterministicArchives);
194     if (!Member)
195       return createFileError(Ar.getFileName(), Member.takeError());
196     Member->Buf = MB.releaseMemoryBuffer();
197     Member->MemberName = Member->Buf->getBufferIdentifier();
198     NewArchiveMembers.push_back(std::move(*Member));
199   }
200   if (Err)
201     return createFileError(Config.InputFilename, std::move(Err));
202 
203   return deepWriteArchive(Config.OutputFilename, NewArchiveMembers,
204                           Ar.hasSymbolTable(), Ar.kind(),
205                           Config.DeterministicArchives, Ar.isThin());
206 }
207 
208 static Error restoreStatOnFile(StringRef Filename,
209                                const sys::fs::file_status &Stat,
210                                bool PreserveDates) {
211   int FD;
212 
213   // Writing to stdout should not be treated as an error here, just
214   // do not set access/modification times or permissions.
215   if (Filename == "-")
216     return Error::success();
217 
218   if (auto EC =
219           sys::fs::openFileForWrite(Filename, FD, sys::fs::CD_OpenExisting))
220     return createFileError(Filename, EC);
221 
222   if (PreserveDates)
223     if (auto EC = sys::fs::setLastAccessAndModificationTime(
224             FD, Stat.getLastAccessedTime(), Stat.getLastModificationTime()))
225       return createFileError(Filename, EC);
226 
227   sys::fs::file_status OStat;
228   if (std::error_code EC = sys::fs::status(FD, OStat))
229     return createFileError(Filename, EC);
230   if (OStat.type() == sys::fs::file_type::regular_file)
231 #ifdef _WIN32
232     if (auto EC = sys::fs::setPermissions(
233             Filename, static_cast<sys::fs::perms>(Stat.permissions() &
234                                                   ~sys::fs::getUmask())))
235 #else
236     if (auto EC = sys::fs::setPermissions(
237             FD, static_cast<sys::fs::perms>(Stat.permissions() &
238                                             ~sys::fs::getUmask())))
239 #endif
240       return createFileError(Filename, EC);
241 
242   if (auto EC = sys::Process::SafelyCloseFileDescriptor(FD))
243     return createFileError(Filename, EC);
244 
245   return Error::success();
246 }
247 
248 /// The function executeObjcopy does the higher level dispatch based on the type
249 /// of input (raw binary, archive or single object file) and takes care of the
250 /// format-agnostic modifications, i.e. preserving dates.
251 static Error executeObjcopy(const CopyConfig &Config) {
252   sys::fs::file_status Stat;
253   if (Config.InputFilename != "-") {
254     if (auto EC = sys::fs::status(Config.InputFilename, Stat))
255       return createFileError(Config.InputFilename, EC);
256   } else {
257     Stat.permissions(static_cast<sys::fs::perms>(0777));
258   }
259 
260   typedef Error (*ProcessRawFn)(const CopyConfig &, MemoryBuffer &, Buffer &);
261   ProcessRawFn ProcessRaw;
262   switch (Config.InputFormat) {
263   case FileFormat::Binary:
264     ProcessRaw = executeObjcopyOnRawBinary;
265     break;
266   case FileFormat::IHex:
267     ProcessRaw = executeObjcopyOnIHex;
268     break;
269   default:
270     ProcessRaw = nullptr;
271   }
272 
273   if (ProcessRaw) {
274     auto BufOrErr = MemoryBuffer::getFileOrSTDIN(Config.InputFilename);
275     if (!BufOrErr)
276       return createFileError(Config.InputFilename, BufOrErr.getError());
277     FileBuffer FB(Config.OutputFilename);
278     if (Error E = ProcessRaw(Config, *BufOrErr->get(), FB))
279       return E;
280   } else {
281     Expected<OwningBinary<llvm::object::Binary>> BinaryOrErr =
282         createBinary(Config.InputFilename);
283     if (!BinaryOrErr)
284       return createFileError(Config.InputFilename, BinaryOrErr.takeError());
285 
286     if (Archive *Ar = dyn_cast<Archive>(BinaryOrErr.get().getBinary())) {
287       if (Error E = executeObjcopyOnArchive(Config, *Ar))
288         return E;
289     } else {
290       FileBuffer FB(Config.OutputFilename);
291       if (Error E = executeObjcopyOnBinary(Config,
292                                            *BinaryOrErr.get().getBinary(), FB))
293         return E;
294     }
295   }
296 
297   if (Error E =
298           restoreStatOnFile(Config.OutputFilename, Stat, Config.PreserveDates))
299     return E;
300 
301   if (!Config.SplitDWO.empty()) {
302     Stat.permissions(static_cast<sys::fs::perms>(0666));
303     if (Error E =
304             restoreStatOnFile(Config.SplitDWO, Stat, Config.PreserveDates))
305       return E;
306   }
307 
308   return Error::success();
309 }
310 
311 int main(int argc, char **argv) {
312   InitLLVM X(argc, argv);
313   ToolName = argv[0];
314   bool IsStrip = sys::path::stem(ToolName).contains("strip");
315 
316   // Expand response files.
317   // TODO: Move these lines, which are copied from lib/Support/CommandLine.cpp,
318   // into a separate function in the CommandLine library and call that function
319   // here. This is duplicated code.
320   SmallVector<const char *, 20> NewArgv(argv, argv + argc);
321   BumpPtrAllocator A;
322   StringSaver Saver(A);
323   cl::ExpandResponseFiles(Saver,
324                           Triple(sys::getProcessTriple()).isOSWindows()
325                               ? cl::TokenizeWindowsCommandLine
326                               : cl::TokenizeGNUCommandLine,
327                           NewArgv);
328 
329   auto Args = makeArrayRef(NewArgv).drop_front();
330 
331   Expected<DriverConfig> DriverConfig =
332       IsStrip ? parseStripOptions(Args, reportWarning)
333               : parseObjcopyOptions(Args);
334   if (!DriverConfig) {
335     logAllUnhandledErrors(DriverConfig.takeError(),
336                           WithColor::error(errs(), ToolName));
337     return 1;
338   }
339   for (const CopyConfig &CopyConfig : DriverConfig->CopyConfigs) {
340     if (Error E = executeObjcopy(CopyConfig)) {
341       logAllUnhandledErrors(std::move(E), WithColor::error(errs(), ToolName));
342       return 1;
343     }
344   }
345 
346   return 0;
347 }
348