tools/llvm-objcopy/llvm-objcopy.cpp

   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<std::unique_ptr<Binary>> ChildOrErr = Child.getAsBinary();
 158     if (!ChildOrErr)
 159       return createFileError(Ar.getFileName(), ChildOrErr.takeError());
 160     Binary *Bin = ChildOrErr->get();
 161
 162     Expected<StringRef> ChildNameOrErr = Child.getName();
 163     if (!ChildNameOrErr)
 164       return createFileError(Ar.getFileName(), ChildNameOrErr.takeError());
 165
 166     MemBuffer MB(ChildNameOrErr.get());
 167     if (Error E = executeObjcopyOnBinary(Config, *Bin, 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 void 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     reportError(Filename, EC);
 193
 194   if (auto EC = sys::fs::setLastAccessAndModificationTime(
 195           FD, Stat.getLastAccessedTime(), Stat.getLastModificationTime()))
 196     reportError(Filename, EC);
 197
 198   if (auto EC = sys::Process::SafelyCloseFileDescriptor(FD))
 199     reportError(Filename, EC);
 200 }
 201
 202 /// The function executeObjcopy does the higher level dispatch based on the type
 203 /// of input (raw binary, archive or single object file) and takes care of the
 204 /// format-agnostic modifications, i.e. preserving dates.
 205 static void executeObjcopy(const CopyConfig &Config) {
 206   sys::fs::file_status Stat;
 207   if (Config.PreserveDates)
 208     if (auto EC = sys::fs::status(Config.InputFilename, Stat))
 209       reportError(Config.InputFilename, EC);
 210
 211   if (Config.InputFormat == "binary") {
 212     auto BufOrErr = MemoryBuffer::getFile(Config.InputFilename);
 213     if (!BufOrErr)
 214       reportError(Config.InputFilename, BufOrErr.getError());
 215     FileBuffer FB(Config.OutputFilename);
 216     if (Error E = executeObjcopyOnRawBinary(Config, *BufOrErr->get(), FB))
 217       error(std::move(E));
 218   } else {
 219     Expected<OwningBinary<llvm::object::Binary>> BinaryOrErr =
 220         createBinary(Config.InputFilename);
 221     if (!BinaryOrErr)
 222       reportError(Config.InputFilename, BinaryOrErr.takeError());
 223
 224     if (Archive *Ar = dyn_cast<Archive>(BinaryOrErr.get().getBinary())) {
 225       if (Error E = executeObjcopyOnArchive(Config, *Ar))
 226         error(std::move(E));
 227     } else {
 228       FileBuffer FB(Config.OutputFilename);
 229       if (Error E = executeObjcopyOnBinary(Config,
 230                                            *BinaryOrErr.get().getBinary(), FB))
 231         error(std::move(E));
 232     }
 233   }
 234
 235   if (Config.PreserveDates) {
 236     restoreDateOnFile(Config.OutputFilename, Stat);
 237     if (!Config.SplitDWO.empty())
 238       restoreDateOnFile(Config.SplitDWO, Stat);
 239   }
 240 }
 241
 242 int main(int argc, char **argv) {
 243   InitLLVM X(argc, argv);
 244   ToolName = argv[0];
 245   DriverConfig DriverConfig;
 246   if (sys::path::stem(ToolName).contains("strip"))
 247     DriverConfig = parseStripOptions(makeArrayRef(argv + 1, argc));
 248   else
 249     DriverConfig = parseObjcopyOptions(makeArrayRef(argv + 1, argc));
 250   for (const CopyConfig &CopyConfig : DriverConfig.CopyConfigs)
 251     executeObjcopy(CopyConfig);
 252 }