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 "COFF/COFFObjcopy.h"
12 #include "CopyConfig.h"
13 #include "ELF/ELFObjcopy.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/Error.h"
33 #include "llvm/Support/ErrorHandling.h"
34 #include "llvm/Support/ErrorOr.h"
35 #include "llvm/Support/InitLLVM.h"
36 #include "llvm/Support/Memory.h"
37 #include "llvm/Support/Path.h"
38 #include "llvm/Support/Process.h"
39 #include "llvm/Support/WithColor.h"
40 #include "llvm/Support/raw_ostream.h"
41 #include <algorithm>
42 #include <cassert>
43 #include <cstdlib>
44 #include <memory>
45 #include <string>
46 #include <system_error>
47 #include <utility>
48 
49 namespace llvm {
50 namespace objcopy {
51 
52 // The name this program was invoked as.
53 StringRef ToolName;
54 
55 LLVM_ATTRIBUTE_NORETURN void error(Twine Message) {
56   WithColor::error(errs(), ToolName) << Message << ".\n";
57   errs().flush();
58   exit(1);
59 }
60 
61 LLVM_ATTRIBUTE_NORETURN void error(Error E) {
62   assert(E);
63   std::string Buf;
64   raw_string_ostream OS(Buf);
65   logAllUnhandledErrors(std::move(E), OS);
66   OS.flush();
67   WithColor::error(errs(), ToolName) << Buf;
68   exit(1);
69 }
70 
71 LLVM_ATTRIBUTE_NORETURN void reportError(StringRef File, std::error_code EC) {
72   assert(EC);
73   error(createFileError(File, EC));
74 }
75 
76 LLVM_ATTRIBUTE_NORETURN void reportError(StringRef File, Error E) {
77   assert(E);
78   std::string Buf;
79   raw_string_ostream OS(Buf);
80   logAllUnhandledErrors(std::move(E), OS);
81   OS.flush();
82   WithColor::error(errs(), ToolName) << "'" << File << "': " << Buf;
83   exit(1);
84 }
85 
86 } // end namespace objcopy
87 } // end namespace llvm
88 
89 using namespace llvm;
90 using namespace llvm::object;
91 using namespace llvm::objcopy;
92 
93 // For regular archives this function simply calls llvm::writeArchive,
94 // For thin archives it writes the archive file itself as well as its members.
95 static Error deepWriteArchive(StringRef ArcName,
96                               ArrayRef<NewArchiveMember> NewMembers,
97                               bool WriteSymtab, object::Archive::Kind Kind,
98                               bool Deterministic, bool Thin) {
99   if (Error E = writeArchive(ArcName, NewMembers, WriteSymtab, Kind,
100                              Deterministic, Thin))
101     return createFileError(ArcName, std::move(E));
102 
103   if (!Thin)
104     return Error::success();
105 
106   for (const NewArchiveMember &Member : NewMembers) {
107     // Internally, FileBuffer will use the buffer created by
108     // FileOutputBuffer::create, for regular files (that is the case for
109     // deepWriteArchive) FileOutputBuffer::create will return OnDiskBuffer.
110     // OnDiskBuffer uses a temporary file and then renames it. So in reality
111     // there is no inefficiency / duplicated in-memory buffers in this case. For
112     // now in-memory buffers can not be completely avoided since
113     // NewArchiveMember still requires them even though writeArchive does not
114     // write them on disk.
115     FileBuffer FB(Member.MemberName);
116     if (Error E = FB.allocate(Member.Buf->getBufferSize()))
117       return E;
118     std::copy(Member.Buf->getBufferStart(), Member.Buf->getBufferEnd(),
119               FB.getBufferStart());
120     if (Error E = FB.commit())
121       return E;
122   }
123   return Error::success();
124 }
125 
126 /// The function executeObjcopyOnRawBinary does the dispatch based on the format
127 /// of the output specified by the command line options.
128 static Error executeObjcopyOnRawBinary(const CopyConfig &Config,
129                                        MemoryBuffer &In, Buffer &Out) {
130   // TODO: llvm-objcopy should parse CopyConfig.OutputFormat to recognize
131   // formats other than ELF / "binary" and invoke
132   // elf::executeObjcopyOnRawBinary, macho::executeObjcopyOnRawBinary or
133   // coff::executeObjcopyOnRawBinary accordingly.
134   return elf::executeObjcopyOnRawBinary(Config, In, Out);
135 }
136 
137 /// The function executeObjcopyOnBinary does the dispatch based on the format
138 /// of the input binary (ELF, MachO or COFF).
139 static Error executeObjcopyOnBinary(const CopyConfig &Config,
140                                     object::Binary &In, Buffer &Out) {
141   if (auto *ELFBinary = dyn_cast<object::ELFObjectFileBase>(&In))
142     return elf::executeObjcopyOnBinary(Config, *ELFBinary, Out);
143   else if (auto *COFFBinary = dyn_cast<object::COFFObjectFile>(&In))
144     return coff::executeObjcopyOnBinary(Config, *COFFBinary, Out);
145   else if (auto *MachOBinary = dyn_cast<object::MachOObjectFile>(&In))
146     return macho::executeObjcopyOnBinary(Config, *MachOBinary, Out);
147   else
148     return createStringError(object_error::invalid_file_type,
149                              "Unsupported object file format");
150 }
151 
152 static Error executeObjcopyOnArchive(const CopyConfig &Config,
153                                      const Archive &Ar) {
154   std::vector<NewArchiveMember> NewArchiveMembers;
155   Error Err = Error::success();
156   for (const Archive::Child &Child : Ar.children(Err)) {
157     Expected<StringRef> ChildNameOrErr = Child.getName();
158     if (!ChildNameOrErr)
159       return createFileError(Ar.getFileName(), ChildNameOrErr.takeError());
160 
161     Expected<std::unique_ptr<Binary>> ChildOrErr = Child.getAsBinary();
162     if (!ChildOrErr)
163       return createFileError(Ar.getFileName() + "(" + *ChildNameOrErr + ")",
164                              ChildOrErr.takeError());
165 
166     MemBuffer MB(ChildNameOrErr.get());
167     if (Error E = executeObjcopyOnBinary(Config, *ChildOrErr->get(), MB))
168       return E;
169 
170     Expected<NewArchiveMember> Member =
171         NewArchiveMember::getOldMember(Child, Config.DeterministicArchives);
172     if (!Member)
173       return createFileError(Ar.getFileName(), Member.takeError());
174     Member->Buf = MB.releaseMemoryBuffer();
175     Member->MemberName = Member->Buf->getBufferIdentifier();
176     NewArchiveMembers.push_back(std::move(*Member));
177   }
178   if (Err)
179     return createFileError(Config.InputFilename, std::move(Err));
180 
181   return deepWriteArchive(Config.OutputFilename, NewArchiveMembers,
182                           Ar.hasSymbolTable(), Ar.kind(),
183                           Config.DeterministicArchives, Ar.isThin());
184 }
185 
186 static Error restoreDateOnFile(StringRef Filename,
187                                const sys::fs::file_status &Stat) {
188   int FD;
189 
190   if (auto EC =
191           sys::fs::openFileForWrite(Filename, FD, sys::fs::CD_OpenExisting))
192     return createFileError(Filename, EC);
193 
194   if (auto EC = sys::fs::setLastAccessAndModificationTime(
195           FD, Stat.getLastAccessedTime(), Stat.getLastModificationTime()))
196     return createFileError(Filename, EC);
197 
198   if (auto EC = sys::Process::SafelyCloseFileDescriptor(FD))
199     return createFileError(Filename, EC);
200 
201   return Error::success();
202 }
203 
204 /// The function executeObjcopy does the higher level dispatch based on the type
205 /// of input (raw binary, archive or single object file) and takes care of the
206 /// format-agnostic modifications, i.e. preserving dates.
207 static Error executeObjcopy(const CopyConfig &Config) {
208   sys::fs::file_status Stat;
209   if (Config.PreserveDates)
210     if (auto EC = sys::fs::status(Config.InputFilename, Stat))
211       return createFileError(Config.InputFilename, EC);
212 
213   if (Config.InputFormat == "binary") {
214     auto BufOrErr = MemoryBuffer::getFile(Config.InputFilename);
215     if (!BufOrErr)
216       return createFileError(Config.InputFilename, BufOrErr.getError());
217     FileBuffer FB(Config.OutputFilename);
218     if (Error E = executeObjcopyOnRawBinary(Config, *BufOrErr->get(), FB))
219       return E;
220   } else {
221     Expected<OwningBinary<llvm::object::Binary>> BinaryOrErr =
222         createBinary(Config.InputFilename);
223     if (!BinaryOrErr)
224       return createFileError(Config.InputFilename, BinaryOrErr.takeError());
225 
226     if (Archive *Ar = dyn_cast<Archive>(BinaryOrErr.get().getBinary())) {
227       if (Error E = executeObjcopyOnArchive(Config, *Ar))
228         return E;
229     } else {
230       FileBuffer FB(Config.OutputFilename);
231       if (Error E = executeObjcopyOnBinary(Config,
232                                            *BinaryOrErr.get().getBinary(), FB))
233         return E;
234     }
235   }
236 
237   if (Config.PreserveDates) {
238     if (Error E = restoreDateOnFile(Config.OutputFilename, Stat))
239       return E;
240     if (!Config.SplitDWO.empty())
241       if (Error E = restoreDateOnFile(Config.SplitDWO, Stat))
242         return E;
243   }
244 
245   return Error::success();
246 }
247 
248 int main(int argc, char **argv) {
249   InitLLVM X(argc, argv);
250   ToolName = argv[0];
251   bool IsStrip = sys::path::stem(ToolName).contains("strip");
252   Expected<DriverConfig> DriverConfig =
253       IsStrip ? parseStripOptions(makeArrayRef(argv + 1, argc))
254               : parseObjcopyOptions(makeArrayRef(argv + 1, argc));
255   if (!DriverConfig) {
256     logAllUnhandledErrors(DriverConfig.takeError(),
257                           WithColor::error(errs(), ToolName));
258     return 1;
259   }
260   for (const CopyConfig &CopyConfig : DriverConfig->CopyConfigs) {
261     if (Error E = executeObjcopy(CopyConfig)) {
262       logAllUnhandledErrors(std::move(E), WithColor::error(errs(), ToolName));
263       return 1;
264     }
265   }
266 
267   return 0;
268 }
269