1 //===- llvm-objcopy.cpp ---------------------------------------------------===//
2 //
3 //                      The LLVM Compiler Infrastructure
4 //
5 // This file is distributed under the University of Illinois Open Source
6 // License. See LICENSE.TXT for details.
7 //
8 //===----------------------------------------------------------------------===//
9 
10 #include "llvm-objcopy.h"
11 #include "Buffer.h"
12 #include "COFF/COFFObjcopy.h"
13 #include "CopyConfig.h"
14 #include "ELF/ELFObjcopy.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/Option/Arg.h"
28 #include "llvm/Option/ArgList.h"
29 #include "llvm/Option/Option.h"
30 #include "llvm/Support/Casting.h"
31 #include "llvm/Support/Error.h"
32 #include "llvm/Support/ErrorHandling.h"
33 #include "llvm/Support/ErrorOr.h"
34 #include "llvm/Support/InitLLVM.h"
35 #include "llvm/Support/Memory.h"
36 #include "llvm/Support/Path.h"
37 #include "llvm/Support/Process.h"
38 #include "llvm/Support/WithColor.h"
39 #include "llvm/Support/raw_ostream.h"
40 #include <algorithm>
41 #include <cassert>
42 #include <cstdlib>
43 #include <memory>
44 #include <string>
45 #include <system_error>
46 #include <utility>
47 
48 namespace llvm {
49 namespace objcopy {
50 
51 // The name this program was invoked as.
52 StringRef ToolName;
53 
54 LLVM_ATTRIBUTE_NORETURN void error(Twine Message) {
55   WithColor::error(errs(), ToolName) << Message << ".\n";
56   errs().flush();
57   exit(1);
58 }
59 
60 LLVM_ATTRIBUTE_NORETURN void reportError(StringRef File, std::error_code EC) {
61   assert(EC);
62   WithColor::error(errs(), ToolName)
63       << "'" << File << "': " << EC.message() << ".\n";
64   exit(1);
65 }
66 
67 LLVM_ATTRIBUTE_NORETURN void reportError(StringRef File, Error E) {
68   assert(E);
69   std::string Buf;
70   raw_string_ostream OS(Buf);
71   logAllUnhandledErrors(std::move(E), OS);
72   OS.flush();
73   WithColor::error(errs(), ToolName) << "'" << File << "': " << Buf;
74   exit(1);
75 }
76 
77 } // end namespace objcopy
78 } // end namespace llvm
79 
80 using namespace llvm;
81 using namespace llvm::object;
82 using namespace llvm::objcopy;
83 
84 // For regular archives this function simply calls llvm::writeArchive,
85 // For thin archives it writes the archive file itself as well as its members.
86 static Error deepWriteArchive(StringRef ArcName,
87                               ArrayRef<NewArchiveMember> NewMembers,
88                               bool WriteSymtab, object::Archive::Kind Kind,
89                               bool Deterministic, bool Thin) {
90   Error E =
91       writeArchive(ArcName, NewMembers, WriteSymtab, Kind, Deterministic, Thin);
92   if (!Thin || E)
93     return E;
94   for (const NewArchiveMember &Member : NewMembers) {
95     // Internally, FileBuffer will use the buffer created by
96     // FileOutputBuffer::create, for regular files (that is the case for
97     // deepWriteArchive) FileOutputBuffer::create will return OnDiskBuffer.
98     // OnDiskBuffer uses a temporary file and then renames it. So in reality
99     // there is no inefficiency / duplicated in-memory buffers in this case. For
100     // now in-memory buffers can not be completely avoided since
101     // NewArchiveMember still requires them even though writeArchive does not
102     // write them on disk.
103     FileBuffer FB(Member.MemberName);
104     FB.allocate(Member.Buf->getBufferSize());
105     std::copy(Member.Buf->getBufferStart(), Member.Buf->getBufferEnd(),
106               FB.getBufferStart());
107     if (auto E = FB.commit())
108       return E;
109   }
110   return Error::success();
111 }
112 
113 /// The function executeObjcopyOnRawBinary does the dispatch based on the format
114 /// of the output specified by the command line options.
115 static void executeObjcopyOnRawBinary(const CopyConfig &Config,
116                                       MemoryBuffer &In, Buffer &Out) {
117   // TODO: llvm-objcopy should parse CopyConfig.OutputFormat to recognize
118   // formats other than ELF / "binary" and invoke
119   // elf::executeObjcopyOnRawBinary, macho::executeObjcopyOnRawBinary or
120   // coff::executeObjcopyOnRawBinary accordingly.
121   return elf::executeObjcopyOnRawBinary(Config, In, Out);
122 }
123 
124 /// The function executeObjcopyOnBinary does the dispatch based on the format
125 /// of the input binary (ELF, MachO or COFF).
126 static void executeObjcopyOnBinary(const CopyConfig &Config, object::Binary &In,
127                                    Buffer &Out) {
128   if (auto *ELFBinary = dyn_cast<object::ELFObjectFileBase>(&In))
129     return elf::executeObjcopyOnBinary(Config, *ELFBinary, Out);
130   else if (auto *COFFBinary = dyn_cast<object::COFFObjectFile>(&In))
131     return coff::executeObjcopyOnBinary(Config, *COFFBinary, Out);
132   else
133     error("Unsupported object file format");
134 }
135 
136 static void executeObjcopyOnArchive(const CopyConfig &Config,
137                                     const Archive &Ar) {
138   std::vector<NewArchiveMember> NewArchiveMembers;
139   Error Err = Error::success();
140   for (const Archive::Child &Child : Ar.children(Err)) {
141     Expected<std::unique_ptr<Binary>> ChildOrErr = Child.getAsBinary();
142     if (!ChildOrErr)
143       reportError(Ar.getFileName(), ChildOrErr.takeError());
144     Binary *Bin = ChildOrErr->get();
145 
146     Expected<StringRef> ChildNameOrErr = Child.getName();
147     if (!ChildNameOrErr)
148       reportError(Ar.getFileName(), ChildNameOrErr.takeError());
149 
150     MemBuffer MB(ChildNameOrErr.get());
151     executeObjcopyOnBinary(Config, *Bin, MB);
152 
153     Expected<NewArchiveMember> Member =
154         NewArchiveMember::getOldMember(Child, Config.DeterministicArchives);
155     if (!Member)
156       reportError(Ar.getFileName(), Member.takeError());
157     Member->Buf = MB.releaseMemoryBuffer();
158     Member->MemberName = Member->Buf->getBufferIdentifier();
159     NewArchiveMembers.push_back(std::move(*Member));
160   }
161 
162   if (Err)
163     reportError(Config.InputFilename, std::move(Err));
164   if (Error E = deepWriteArchive(Config.OutputFilename, NewArchiveMembers,
165                                  Ar.hasSymbolTable(), Ar.kind(),
166                                  Config.DeterministicArchives, Ar.isThin()))
167     reportError(Config.OutputFilename, std::move(E));
168 }
169 
170 static void restoreDateOnFile(StringRef Filename,
171                               const sys::fs::file_status &Stat) {
172   int FD;
173 
174   if (auto EC =
175           sys::fs::openFileForWrite(Filename, FD, sys::fs::CD_OpenExisting))
176     reportError(Filename, EC);
177 
178   if (auto EC = sys::fs::setLastAccessAndModificationTime(
179           FD, Stat.getLastAccessedTime(), Stat.getLastModificationTime()))
180     reportError(Filename, EC);
181 
182   if (auto EC = sys::Process::SafelyCloseFileDescriptor(FD))
183     reportError(Filename, EC);
184 }
185 
186 /// The function executeObjcopy does the higher level dispatch based on the type
187 /// of input (raw binary, archive or single object file) and takes care of the
188 /// format-agnostic modifications, i.e. preserving dates.
189 static void executeObjcopy(const CopyConfig &Config) {
190   sys::fs::file_status Stat;
191   if (Config.PreserveDates)
192     if (auto EC = sys::fs::status(Config.InputFilename, Stat))
193       reportError(Config.InputFilename, EC);
194 
195   if (Config.InputFormat == "binary") {
196     auto BufOrErr = MemoryBuffer::getFile(Config.InputFilename);
197     if (!BufOrErr)
198       reportError(Config.InputFilename, BufOrErr.getError());
199     FileBuffer FB(Config.OutputFilename);
200     executeObjcopyOnRawBinary(Config, *BufOrErr->get(), FB);
201   } else {
202     Expected<OwningBinary<llvm::object::Binary>> BinaryOrErr =
203         createBinary(Config.InputFilename);
204     if (!BinaryOrErr)
205       reportError(Config.InputFilename, BinaryOrErr.takeError());
206 
207     if (Archive *Ar = dyn_cast<Archive>(BinaryOrErr.get().getBinary())) {
208       executeObjcopyOnArchive(Config, *Ar);
209     } else {
210       FileBuffer FB(Config.OutputFilename);
211       executeObjcopyOnBinary(Config, *BinaryOrErr.get().getBinary(), FB);
212     }
213   }
214 
215   if (Config.PreserveDates) {
216     restoreDateOnFile(Config.OutputFilename, Stat);
217     if (!Config.SplitDWO.empty())
218       restoreDateOnFile(Config.SplitDWO, Stat);
219   }
220 }
221 
222 int main(int argc, char **argv) {
223   InitLLVM X(argc, argv);
224   ToolName = argv[0];
225   DriverConfig DriverConfig;
226   if (sys::path::stem(ToolName).contains("strip"))
227     DriverConfig = parseStripOptions(makeArrayRef(argv + 1, argc));
228   else
229     DriverConfig = parseObjcopyOptions(makeArrayRef(argv + 1, argc));
230   for (const CopyConfig &CopyConfig : DriverConfig.CopyConfigs)
231     executeObjcopy(CopyConfig);
232 }
233