llvm-objcopy.cpp revision 344779 
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
48namespace llvm {
49namespace objcopy {
50
51// The name this program was invoked as.
52StringRef ToolName;
53
54LLVM_ATTRIBUTE_NORETURN void error(Twine Message) {
55  WithColor::error(errs(), ToolName) << Message << ".\n";
56  errs().flush();
57  exit(1);
58}
59
60LLVM_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
67LLVM_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
80using namespace llvm;
81using namespace llvm::object;
82using 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.
86static 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.
115static 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).
126static 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
136static 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
170static 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.
189static 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
222int 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