lib/Object/ArchiveWriter.cpp

   1 //===- ArchiveWriter.cpp - ar File Format implementation --------*- C++ -*-===//
   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 // This file defines the writeArchive function.
  11 //
  12 //===----------------------------------------------------------------------===//
  13
  14 #include "llvm/Object/ArchiveWriter.h"
  15 #include "llvm/ADT/ArrayRef.h"
  16 #include "llvm/ADT/StringRef.h"
  17 #include "llvm/IR/LLVMContext.h"
  18 #include "llvm/Object/Archive.h"
  19 #include "llvm/Object/ObjectFile.h"
  20 #include "llvm/Object/SymbolicFile.h"
  21 #include "llvm/Support/EndianStream.h"
  22 #include "llvm/Support/Errc.h"
  23 #include "llvm/Support/ErrorHandling.h"
  24 #include "llvm/Support/Format.h"
  25 #include "llvm/Support/Path.h"
  26 #include "llvm/Support/ToolOutputFile.h"
  27 #include "llvm/Support/raw_ostream.h"
  28
  29 #if !defined(_MSC_VER) && !defined(__MINGW32__)
  30 #include <unistd.h>
  31 #else
  32 #include <io.h>
  33 #endif
  34
  35 using namespace llvm;
  36
  37 NewArchiveIterator::NewArchiveIterator() {}
  38
  39 NewArchiveIterator::NewArchiveIterator(object::Archive::child_iterator I,
  40                                        StringRef Name)
  41     : IsNewMember(false), Name(Name), OldI(I) {}
  42
  43 NewArchiveIterator::NewArchiveIterator(StringRef NewFilename, StringRef Name)
  44     : IsNewMember(true), Name(Name), NewFilename(NewFilename) {}
  45
  46 StringRef NewArchiveIterator::getName() const { return Name; }
  47
  48 bool NewArchiveIterator::isNewMember() const { return IsNewMember; }
  49
  50 object::Archive::child_iterator NewArchiveIterator::getOld() const {
  51   assert(!IsNewMember);
  52   return OldI;
  53 }
  54
  55 StringRef NewArchiveIterator::getNew() const {
  56   assert(IsNewMember);
  57   return NewFilename;
  58 }
  59
  60 llvm::ErrorOr<int>
  61 NewArchiveIterator::getFD(sys::fs::file_status &NewStatus) const {
  62   assert(IsNewMember);
  63   int NewFD;
  64   if (auto EC = sys::fs::openFileForRead(NewFilename, NewFD))
  65     return EC;
  66   assert(NewFD != -1);
  67
  68   if (auto EC = sys::fs::status(NewFD, NewStatus))
  69     return EC;
  70
  71   // Opening a directory doesn't make sense. Let it fail.
  72   // Linux cannot open directories with open(2), although
  73   // cygwin and *bsd can.
  74   if (NewStatus.type() == sys::fs::file_type::directory_file)
  75     return make_error_code(errc::is_a_directory);
  76
  77   return NewFD;
  78 }
  79
  80 template <typename T>
  81 static void printWithSpacePadding(raw_fd_ostream &OS, T Data, unsigned Size,
  82                                   bool MayTruncate = false) {
  83   uint64_t OldPos = OS.tell();
  84   OS << Data;
  85   unsigned SizeSoFar = OS.tell() - OldPos;
  86   if (Size > SizeSoFar) {
  87     OS.indent(Size - SizeSoFar);
  88   } else if (Size < SizeSoFar) {
  89     assert(MayTruncate && "Data doesn't fit in Size");
  90     // Some of the data this is used for (like UID) can be larger than the
  91     // space available in the archive format. Truncate in that case.
  92     OS.seek(OldPos + Size);
  93   }
  94 }
  95
  96 static void print32BE(raw_ostream &Out, uint32_t Val) {
  97   support::endian::Writer<support::big>(Out).write(Val);
  98 }
  99
 100 static void printRestOfMemberHeader(raw_fd_ostream &Out,
 101                                     const sys::TimeValue &ModTime, unsigned UID,
 102                                     unsigned GID, unsigned Perms,
 103                                     unsigned Size) {
 104   printWithSpacePadding(Out, ModTime.toEpochTime(), 12);
 105   printWithSpacePadding(Out, UID, 6, true);
 106   printWithSpacePadding(Out, GID, 6, true);
 107   printWithSpacePadding(Out, format("%o", Perms), 8);
 108   printWithSpacePadding(Out, Size, 10);
 109   Out << "`\n";
 110 }
 111
 112 static void printMemberHeader(raw_fd_ostream &Out, StringRef Name,
 113                               const sys::TimeValue &ModTime, unsigned UID,
 114                               unsigned GID, unsigned Perms, unsigned Size) {
 115   printWithSpacePadding(Out, Twine(Name) + "/", 16);
 116   printRestOfMemberHeader(Out, ModTime, UID, GID, Perms, Size);
 117 }
 118
 119 static void
 120 printMemberHeader(raw_fd_ostream &Out, object::Archive::Kind Kind,
 121                   StringRef Name,
 122                   std::vector<unsigned>::iterator &StringMapIndexIter,
 123                   const sys::TimeValue &ModTime, unsigned UID, unsigned GID,
 124                   unsigned Perms, unsigned Size) {
 125   if (Kind == object::Archive::K_BSD) {
 126     uint64_t PosAfterHeader = Out.tell() + 60 + Name.size();
 127     // Pad so that even 64 bit object files are aligned.
 128     unsigned Pad = OffsetToAlignment(PosAfterHeader, 8);
 129     unsigned NameWithPadding = Name.size() + Pad;
 130     printWithSpacePadding(Out, Twine("#1/") + Twine(NameWithPadding), 16);
 131     printRestOfMemberHeader(Out, ModTime, UID, GID, Perms,
 132                             NameWithPadding + Size);
 133     Out << Name;
 134     assert(PosAfterHeader == Out.tell());
 135     while (Pad--)
 136       Out.write(uint8_t(0));
 137     return;
 138   }
 139   if (Name.size() < 16) {
 140     printMemberHeader(Out, Name, ModTime, UID, GID, Perms, Size);
 141     return;
 142   }
 143   Out << '/';
 144   printWithSpacePadding(Out, *StringMapIndexIter++, 15);
 145   printRestOfMemberHeader(Out, ModTime, UID, GID, Perms, Size);
 146 }
 147
 148 static void writeStringTable(raw_fd_ostream &Out,
 149                              ArrayRef<NewArchiveIterator> Members,
 150                              std::vector<unsigned> &StringMapIndexes) {
 151   unsigned StartOffset = 0;
 152   for (ArrayRef<NewArchiveIterator>::iterator I = Members.begin(),
 153                                               E = Members.end();
 154        I != E; ++I) {
 155     StringRef Name = I->getName();
 156     if (Name.size() < 16)
 157       continue;
 158     if (StartOffset == 0) {
 159       printWithSpacePadding(Out, "//", 58);
 160       Out << "`\n";
 161       StartOffset = Out.tell();
 162     }
 163     StringMapIndexes.push_back(Out.tell() - StartOffset);
 164     Out << Name << "/\n";
 165   }
 166   if (StartOffset == 0)
 167     return;
 168   if (Out.tell() % 2)
 169     Out << '\n';
 170   int Pos = Out.tell();
 171   Out.seek(StartOffset - 12);
 172   printWithSpacePadding(Out, Pos - StartOffset, 10);
 173   Out.seek(Pos);
 174 }
 175
 176 // Returns the offset of the first reference to a member offset.
 177 static ErrorOr<unsigned>
 178 writeSymbolTable(raw_fd_ostream &Out, object::Archive::Kind Kind,
 179                  ArrayRef<NewArchiveIterator> Members,
 180                  ArrayRef<MemoryBufferRef> Buffers,
 181                  std::vector<unsigned> &MemberOffsetRefs) {
 182   if (Kind != object::Archive::K_GNU)
 183     return 0;
 184
 185   unsigned StartOffset = 0;
 186   unsigned MemberNum = 0;
 187   std::string NameBuf;
 188   raw_string_ostream NameOS(NameBuf);
 189   unsigned NumSyms = 0;
 190   LLVMContext Context;
 191   for (ArrayRef<NewArchiveIterator>::iterator I = Members.begin(),
 192                                               E = Members.end();
 193        I != E; ++I, ++MemberNum) {
 194     MemoryBufferRef MemberBuffer = Buffers[MemberNum];
 195     ErrorOr<std::unique_ptr<object::SymbolicFile>> ObjOrErr =
 196         object::SymbolicFile::createSymbolicFile(
 197             MemberBuffer, sys::fs::file_magic::unknown, &Context);
 198     if (!ObjOrErr)
 199       continue;  // FIXME: check only for "not an object file" errors.
 200     object::SymbolicFile &Obj = *ObjOrErr.get();
 201
 202     if (!StartOffset) {
 203       printMemberHeader(Out, "", sys::TimeValue::now(), 0, 0, 0, 0);
 204       StartOffset = Out.tell();
 205       print32BE(Out, 0);
 206     }
 207
 208     for (const object::BasicSymbolRef &S : Obj.symbols()) {
 209       uint32_t Symflags = S.getFlags();
 210       if (Symflags & object::SymbolRef::SF_FormatSpecific)
 211         continue;
 212       if (!(Symflags & object::SymbolRef::SF_Global))
 213         continue;
 214       if (Symflags & object::SymbolRef::SF_Undefined)
 215         continue;
 216       if (auto EC = S.printName(NameOS))
 217         return EC;
 218       NameOS << '\0';
 219       ++NumSyms;
 220       MemberOffsetRefs.push_back(MemberNum);
 221       print32BE(Out, 0);
 222     }
 223   }
 224   Out << NameOS.str();
 225
 226   if (StartOffset == 0)
 227     return 0;
 228
 229   if (Out.tell() % 2)
 230     Out << '\0';
 231
 232   unsigned Pos = Out.tell();
 233   Out.seek(StartOffset - 12);
 234   printWithSpacePadding(Out, Pos - StartOffset, 10);
 235   Out.seek(StartOffset);
 236   print32BE(Out, NumSyms);
 237   Out.seek(Pos);
 238   return StartOffset + 4;
 239 }
 240
 241 std::pair<StringRef, std::error_code>
 242 llvm::writeArchive(StringRef ArcName,
 243                    std::vector<NewArchiveIterator> &NewMembers,
 244                    bool WriteSymtab, object::Archive::Kind Kind) {
 245   SmallString<128> TmpArchive;
 246   int TmpArchiveFD;
 247   if (auto EC = sys::fs::createUniqueFile(ArcName + ".temp-archive-%%%%%%%.a",
 248                                           TmpArchiveFD, TmpArchive))
 249     return std::make_pair(ArcName, EC);
 250
 251   tool_output_file Output(TmpArchive, TmpArchiveFD);
 252   raw_fd_ostream &Out = Output.os();
 253   Out << "!<arch>\n";
 254
 255   std::vector<unsigned> MemberOffsetRefs;
 256
 257   std::vector<std::unique_ptr<MemoryBuffer>> Buffers;
 258   std::vector<MemoryBufferRef> Members;
 259   std::vector<sys::fs::file_status> NewMemberStatus;
 260
 261   for (unsigned I = 0, N = NewMembers.size(); I < N; ++I) {
 262     NewArchiveIterator &Member = NewMembers[I];
 263     MemoryBufferRef MemberRef;
 264
 265     if (Member.isNewMember()) {
 266       StringRef Filename = Member.getNew();
 267       NewMemberStatus.resize(NewMemberStatus.size() + 1);
 268       sys::fs::file_status &Status = NewMemberStatus.back();
 269       ErrorOr<int> FD = Member.getFD(Status);
 270       if (auto EC = FD.getError())
 271         return std::make_pair(Filename, EC);
 272       ErrorOr<std::unique_ptr<MemoryBuffer>> MemberBufferOrErr =
 273           MemoryBuffer::getOpenFile(FD.get(), Filename, Status.getSize(),
 274                                     false);
 275       if (auto EC = MemberBufferOrErr.getError())
 276         return std::make_pair(Filename, EC);
 277       if (close(FD.get()) != 0)
 278         return std::make_pair(Filename,
 279                               std::error_code(errno, std::generic_category()));
 280       Buffers.push_back(std::move(MemberBufferOrErr.get()));
 281       MemberRef = Buffers.back()->getMemBufferRef();
 282     } else {
 283       object::Archive::child_iterator OldMember = Member.getOld();
 284       ErrorOr<MemoryBufferRef> MemberBufferOrErr =
 285           OldMember->getMemoryBufferRef();
 286       if (auto EC = MemberBufferOrErr.getError())
 287         return std::make_pair("", EC);
 288       MemberRef = MemberBufferOrErr.get();
 289     }
 290     Members.push_back(MemberRef);
 291   }
 292
 293   unsigned MemberReferenceOffset = 0;
 294   if (WriteSymtab) {
 295     ErrorOr<unsigned> MemberReferenceOffsetOrErr =
 296         writeSymbolTable(Out, Kind, NewMembers, Members, MemberOffsetRefs);
 297     if (auto EC = MemberReferenceOffsetOrErr.getError())
 298       return std::make_pair(ArcName, EC);
 299     MemberReferenceOffset = MemberReferenceOffsetOrErr.get();
 300   }
 301
 302   std::vector<unsigned> StringMapIndexes;
 303   if (Kind != object::Archive::K_BSD)
 304     writeStringTable(Out, NewMembers, StringMapIndexes);
 305
 306   unsigned MemberNum = 0;
 307   unsigned NewMemberNum = 0;
 308   std::vector<unsigned>::iterator StringMapIndexIter = StringMapIndexes.begin();
 309   std::vector<unsigned> MemberOffset;
 310   for (const NewArchiveIterator &I : NewMembers) {
 311     MemoryBufferRef File = Members[MemberNum++];
 312
 313     unsigned Pos = Out.tell();
 314     MemberOffset.push_back(Pos);
 315
 316     if (I.isNewMember()) {
 317       StringRef FileName = I.getNew();
 318       const sys::fs::file_status &Status = NewMemberStatus[NewMemberNum++];
 319       printMemberHeader(Out, Kind, sys::path::filename(FileName),
 320                         StringMapIndexIter, Status.getLastModificationTime(),
 321                         Status.getUser(), Status.getGroup(),
 322                         Status.permissions(), Status.getSize());
 323     } else {
 324       object::Archive::child_iterator OldMember = I.getOld();
 325       printMemberHeader(Out, Kind, I.getName(), StringMapIndexIter,
 326                         OldMember->getLastModified(), OldMember->getUID(),
 327                         OldMember->getGID(), OldMember->getAccessMode(),
 328                         OldMember->getSize());
 329     }
 330
 331     Out << File.getBuffer();
 332
 333     if (Out.tell() % 2)
 334       Out << '\n';
 335   }
 336
 337   if (MemberReferenceOffset) {
 338     Out.seek(MemberReferenceOffset);
 339     for (unsigned MemberNum : MemberOffsetRefs)
 340       print32BE(Out, MemberOffset[MemberNum]);
 341   }
 342
 343   Output.keep();
 344   Out.close();
 345   sys::fs::rename(TmpArchive, ArcName);
 346   return std::make_pair("", std::error_code());
 347 }