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 printMemberHeader(raw_fd_ostream &Out, unsigned NameOffset,
 120                               const sys::TimeValue &ModTime, unsigned UID,
 121                               unsigned GID, unsigned Perms, unsigned Size) {
 122   Out << '/';
 123   printWithSpacePadding(Out, NameOffset, 15);
 124   printRestOfMemberHeader(Out, ModTime, UID, GID, Perms, Size);
 125 }
 126
 127 static void
 128 printMemberHeader(raw_fd_ostream &Out, StringRef Name,
 129                   std::vector<unsigned>::iterator &StringMapIndexIter,
 130                   const sys::TimeValue &ModTime, unsigned UID, unsigned GID,
 131                   unsigned Perms, unsigned Size) {
 132   if (Name.size() < 16)
 133     printMemberHeader(Out, Name, ModTime, UID, GID, Perms, Size);
 134   else
 135     printMemberHeader(Out, *StringMapIndexIter++, ModTime, UID, GID, Perms,
 136                       Size);
 137 }
 138
 139 static void writeStringTable(raw_fd_ostream &Out,
 140                              ArrayRef<NewArchiveIterator> Members,
 141                              std::vector<unsigned> &StringMapIndexes) {
 142   unsigned StartOffset = 0;
 143   for (ArrayRef<NewArchiveIterator>::iterator I = Members.begin(),
 144                                               E = Members.end();
 145        I != E; ++I) {
 146     StringRef Name = I->getName();
 147     if (Name.size() < 16)
 148       continue;
 149     if (StartOffset == 0) {
 150       printWithSpacePadding(Out, "//", 58);
 151       Out << "`\n";
 152       StartOffset = Out.tell();
 153     }
 154     StringMapIndexes.push_back(Out.tell() - StartOffset);
 155     Out << Name << "/\n";
 156   }
 157   if (StartOffset == 0)
 158     return;
 159   if (Out.tell() % 2)
 160     Out << '\n';
 161   int Pos = Out.tell();
 162   Out.seek(StartOffset - 12);
 163   printWithSpacePadding(Out, Pos - StartOffset, 10);
 164   Out.seek(Pos);
 165 }
 166
 167 // Returns the offset of the first reference to a member offset.
 168 static ErrorOr<unsigned>
 169 writeSymbolTable(raw_fd_ostream &Out, ArrayRef<NewArchiveIterator> Members,
 170                  ArrayRef<MemoryBufferRef> Buffers,
 171                  std::vector<unsigned> &MemberOffsetRefs) {
 172   unsigned StartOffset = 0;
 173   unsigned MemberNum = 0;
 174   std::string NameBuf;
 175   raw_string_ostream NameOS(NameBuf);
 176   unsigned NumSyms = 0;
 177   LLVMContext Context;
 178   for (ArrayRef<NewArchiveIterator>::iterator I = Members.begin(),
 179                                               E = Members.end();
 180        I != E; ++I, ++MemberNum) {
 181     MemoryBufferRef MemberBuffer = Buffers[MemberNum];
 182     ErrorOr<std::unique_ptr<object::SymbolicFile>> ObjOrErr =
 183         object::SymbolicFile::createSymbolicFile(
 184             MemberBuffer, sys::fs::file_magic::unknown, &Context);
 185     if (!ObjOrErr)
 186       continue;  // FIXME: check only for "not an object file" errors.
 187     object::SymbolicFile &Obj = *ObjOrErr.get();
 188
 189     if (!StartOffset) {
 190       printMemberHeader(Out, "", sys::TimeValue::now(), 0, 0, 0, 0);
 191       StartOffset = Out.tell();
 192       print32BE(Out, 0);
 193     }
 194
 195     for (const object::BasicSymbolRef &S : Obj.symbols()) {
 196       uint32_t Symflags = S.getFlags();
 197       if (Symflags & object::SymbolRef::SF_FormatSpecific)
 198         continue;
 199       if (!(Symflags & object::SymbolRef::SF_Global))
 200         continue;
 201       if (Symflags & object::SymbolRef::SF_Undefined)
 202         continue;
 203       if (auto EC = S.printName(NameOS))
 204         return EC;
 205       NameOS << '\0';
 206       ++NumSyms;
 207       MemberOffsetRefs.push_back(MemberNum);
 208       print32BE(Out, 0);
 209     }
 210   }
 211   Out << NameOS.str();
 212
 213   if (StartOffset == 0)
 214     return 0;
 215
 216   if (Out.tell() % 2)
 217     Out << '\0';
 218
 219   unsigned Pos = Out.tell();
 220   Out.seek(StartOffset - 12);
 221   printWithSpacePadding(Out, Pos - StartOffset, 10);
 222   Out.seek(StartOffset);
 223   print32BE(Out, NumSyms);
 224   Out.seek(Pos);
 225   return StartOffset + 4;
 226 }
 227
 228 std::pair<StringRef, std::error_code>
 229 llvm::writeArchive(StringRef ArcName,
 230                    std::vector<NewArchiveIterator> &NewMembers,
 231                    bool WriteSymtab) {
 232   SmallString<128> TmpArchive;
 233   int TmpArchiveFD;
 234   if (auto EC = sys::fs::createUniqueFile(ArcName + ".temp-archive-%%%%%%%.a",
 235                                           TmpArchiveFD, TmpArchive))
 236     return std::make_pair(ArcName, EC);
 237
 238   tool_output_file Output(TmpArchive, TmpArchiveFD);
 239   raw_fd_ostream &Out = Output.os();
 240   Out << "!<arch>\n";
 241
 242   std::vector<unsigned> MemberOffsetRefs;
 243
 244   std::vector<std::unique_ptr<MemoryBuffer>> Buffers;
 245   std::vector<MemoryBufferRef> Members;
 246   std::vector<sys::fs::file_status> NewMemberStatus;
 247
 248   for (unsigned I = 0, N = NewMembers.size(); I < N; ++I) {
 249     NewArchiveIterator &Member = NewMembers[I];
 250     MemoryBufferRef MemberRef;
 251
 252     if (Member.isNewMember()) {
 253       StringRef Filename = Member.getNew();
 254       NewMemberStatus.resize(NewMemberStatus.size() + 1);
 255       sys::fs::file_status &Status = NewMemberStatus.back();
 256       ErrorOr<int> FD = Member.getFD(Status);
 257       if (auto EC = FD.getError())
 258         return std::make_pair(Filename, EC);
 259       ErrorOr<std::unique_ptr<MemoryBuffer>> MemberBufferOrErr =
 260           MemoryBuffer::getOpenFile(FD.get(), Filename, Status.getSize(),
 261                                     false);
 262       if (auto EC = MemberBufferOrErr.getError())
 263         return std::make_pair(Filename, EC);
 264       if (close(FD.get()) != 0)
 265         return std::make_pair(Filename,
 266                               std::error_code(errno, std::generic_category()));
 267       Buffers.push_back(std::move(MemberBufferOrErr.get()));
 268       MemberRef = Buffers.back()->getMemBufferRef();
 269     } else {
 270       object::Archive::child_iterator OldMember = Member.getOld();
 271       ErrorOr<MemoryBufferRef> MemberBufferOrErr =
 272           OldMember->getMemoryBufferRef();
 273       if (auto EC = MemberBufferOrErr.getError())
 274         return std::make_pair("", EC);
 275       MemberRef = MemberBufferOrErr.get();
 276     }
 277     Members.push_back(MemberRef);
 278   }
 279
 280   unsigned MemberReferenceOffset = 0;
 281   if (WriteSymtab) {
 282     ErrorOr<unsigned> MemberReferenceOffsetOrErr =
 283         writeSymbolTable(Out, NewMembers, Members, MemberOffsetRefs);
 284     if (auto EC = MemberReferenceOffsetOrErr.getError())
 285       return std::make_pair(ArcName, EC);
 286     MemberReferenceOffset = MemberReferenceOffsetOrErr.get();
 287   }
 288
 289   std::vector<unsigned> StringMapIndexes;
 290   writeStringTable(Out, NewMembers, StringMapIndexes);
 291
 292   unsigned MemberNum = 0;
 293   unsigned NewMemberNum = 0;
 294   std::vector<unsigned>::iterator StringMapIndexIter = StringMapIndexes.begin();
 295   std::vector<unsigned> MemberOffset;
 296   for (const NewArchiveIterator &I : NewMembers) {
 297     MemoryBufferRef File = Members[MemberNum++];
 298
 299     unsigned Pos = Out.tell();
 300     MemberOffset.push_back(Pos);
 301
 302     if (I.isNewMember()) {
 303       StringRef FileName = I.getNew();
 304       const sys::fs::file_status &Status = NewMemberStatus[NewMemberNum++];
 305       printMemberHeader(Out, sys::path::filename(FileName), StringMapIndexIter,
 306                         Status.getLastModificationTime(), Status.getUser(),
 307                         Status.getGroup(), Status.permissions(),
 308                         Status.getSize());
 309     } else {
 310       object::Archive::child_iterator OldMember = I.getOld();
 311       printMemberHeader(Out, I.getName(), StringMapIndexIter,
 312                         OldMember->getLastModified(), OldMember->getUID(),
 313                         OldMember->getGID(), OldMember->getAccessMode(),
 314                         OldMember->getSize());
 315     }
 316
 317     Out << File.getBuffer();
 318
 319     if (Out.tell() % 2)
 320       Out << '\n';
 321   }
 322
 323   if (MemberReferenceOffset) {
 324     Out.seek(MemberReferenceOffset);
 325     for (unsigned MemberNum : MemberOffsetRefs)
 326       print32BE(Out, MemberOffset[MemberNum]);
 327   }
 328
 329   Output.keep();
 330   Out.close();
 331   sys::fs::rename(TmpArchive, ArcName);
 332   return std::make_pair("", std::error_code());
 333 }