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/ErrorHandling.h"
  22 #include "llvm/Support/Format.h"
  23 #include "llvm/Support/Path.h"
  24 #include "llvm/Support/ToolOutputFile.h"
  25 #include "llvm/Support/raw_ostream.h"
  26
  27 #if !defined(_MSC_VER) && !defined(__MINGW32__)
  28 #include <unistd.h>
  29 #else
  30 #include <io.h>
  31 #endif
  32
  33 using namespace llvm;
  34
  35 NewArchiveIterator::NewArchiveIterator() {}
  36
  37 NewArchiveIterator::NewArchiveIterator(object::Archive::child_iterator I,
  38                                        StringRef Name)
  39     : IsNewMember(false), Name(Name), OldI(I) {}
  40
  41 NewArchiveIterator::NewArchiveIterator(StringRef NewFilename, StringRef Name)
  42     : IsNewMember(true), Name(Name), NewFilename(NewFilename) {}
  43
  44 StringRef NewArchiveIterator::getName() const { return Name; }
  45
  46 bool NewArchiveIterator::isNewMember() const { return IsNewMember; }
  47
  48 object::Archive::child_iterator NewArchiveIterator::getOld() const {
  49   assert(!IsNewMember);
  50   return OldI;
  51 }
  52
  53 StringRef NewArchiveIterator::getNew() const {
  54   assert(IsNewMember);
  55   return NewFilename;
  56 }
  57
  58 llvm::ErrorOr<int>
  59 NewArchiveIterator::getFD(sys::fs::file_status &NewStatus) const {
  60   assert(IsNewMember);
  61   int NewFD;
  62   if (auto EC = sys::fs::openFileForRead(NewFilename, NewFD))
  63     return EC;
  64   assert(NewFD != -1);
  65
  66   if (auto EC = sys::fs::status(NewFD, NewStatus))
  67     return EC;
  68
  69   // Opening a directory doesn't make sense. Let it fail.
  70   // Linux cannot open directories with open(2), although
  71   // cygwin and *bsd can.
  72   if (NewStatus.type() == sys::fs::file_type::directory_file)
  73     return make_error_code(std::errc::is_a_directory);
  74
  75   return NewFD;
  76 }
  77
  78 template <typename T>
  79 static void printWithSpacePadding(raw_fd_ostream &OS, T Data, unsigned Size,
  80                                   bool MayTruncate = false) {
  81   uint64_t OldPos = OS.tell();
  82   OS << Data;
  83   unsigned SizeSoFar = OS.tell() - OldPos;
  84   if (Size > SizeSoFar) {
  85     unsigned Remaining = Size - SizeSoFar;
  86     for (unsigned I = 0; I < Remaining; ++I)
  87       OS << ' ';
  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_fd_ostream &Out, unsigned Val) {
  97   // FIXME: Should use Endian.h here.
  98   for (int I = 3; I >= 0; --I) {
  99     char V = (Val >> (8 * I)) & 0xff;
 100     Out << V;
 101   }
 102 }
 103
 104 static void printRestOfMemberHeader(raw_fd_ostream &Out,
 105                                     const sys::TimeValue &ModTime, unsigned UID,
 106                                     unsigned GID, unsigned Perms,
 107                                     unsigned Size) {
 108   printWithSpacePadding(Out, ModTime.toEpochTime(), 12);
 109   printWithSpacePadding(Out, UID, 6, true);
 110   printWithSpacePadding(Out, GID, 6, true);
 111   printWithSpacePadding(Out, format("%o", Perms), 8);
 112   printWithSpacePadding(Out, Size, 10);
 113   Out << "`\n";
 114 }
 115
 116 static void printMemberHeader(raw_fd_ostream &Out, StringRef Name,
 117                               const sys::TimeValue &ModTime, unsigned UID,
 118                               unsigned GID, unsigned Perms, unsigned Size) {
 119   printWithSpacePadding(Out, Twine(Name) + "/", 16);
 120   printRestOfMemberHeader(Out, ModTime, UID, GID, Perms, Size);
 121 }
 122
 123 static void printMemberHeader(raw_fd_ostream &Out, unsigned NameOffset,
 124                               const sys::TimeValue &ModTime, unsigned UID,
 125                               unsigned GID, unsigned Perms, unsigned Size) {
 126   Out << '/';
 127   printWithSpacePadding(Out, NameOffset, 15);
 128   printRestOfMemberHeader(Out, ModTime, UID, GID, Perms, Size);
 129 }
 130
 131 static void writeStringTable(raw_fd_ostream &Out,
 132                              ArrayRef<NewArchiveIterator> Members,
 133                              std::vector<unsigned> &StringMapIndexes) {
 134   unsigned StartOffset = 0;
 135   for (ArrayRef<NewArchiveIterator>::iterator I = Members.begin(),
 136                                               E = Members.end();
 137        I != E; ++I) {
 138     StringRef Name = I->getName();
 139     if (Name.size() < 16)
 140       continue;
 141     if (StartOffset == 0) {
 142       printWithSpacePadding(Out, "//", 58);
 143       Out << "`\n";
 144       StartOffset = Out.tell();
 145     }
 146     StringMapIndexes.push_back(Out.tell() - StartOffset);
 147     Out << Name << "/\n";
 148   }
 149   if (StartOffset == 0)
 150     return;
 151   if (Out.tell() % 2)
 152     Out << '\n';
 153   int Pos = Out.tell();
 154   Out.seek(StartOffset - 12);
 155   printWithSpacePadding(Out, Pos - StartOffset, 10);
 156   Out.seek(Pos);
 157 }
 158
 159 // Returns the offset of the first reference to a member offset.
 160 static ErrorOr<unsigned>
 161 writeSymbolTable(raw_fd_ostream &Out, ArrayRef<NewArchiveIterator> Members,
 162                  ArrayRef<MemoryBufferRef> Buffers,
 163                  std::vector<unsigned> &MemberOffsetRefs) {
 164   unsigned StartOffset = 0;
 165   unsigned MemberNum = 0;
 166   std::string NameBuf;
 167   raw_string_ostream NameOS(NameBuf);
 168   unsigned NumSyms = 0;
 169   LLVMContext Context;
 170   for (ArrayRef<NewArchiveIterator>::iterator I = Members.begin(),
 171                                               E = Members.end();
 172        I != E; ++I, ++MemberNum) {
 173     MemoryBufferRef MemberBuffer = Buffers[MemberNum];
 174     ErrorOr<std::unique_ptr<object::SymbolicFile>> ObjOrErr =
 175         object::SymbolicFile::createSymbolicFile(
 176             MemberBuffer, sys::fs::file_magic::unknown, &Context);
 177     if (!ObjOrErr)
 178       continue;  // FIXME: check only for "not an object file" errors.
 179     object::SymbolicFile &Obj = *ObjOrErr.get();
 180
 181     if (!StartOffset) {
 182       printMemberHeader(Out, "", sys::TimeValue::now(), 0, 0, 0, 0);
 183       StartOffset = Out.tell();
 184       print32BE(Out, 0);
 185     }
 186
 187     for (const object::BasicSymbolRef &S : Obj.symbols()) {
 188       uint32_t Symflags = S.getFlags();
 189       if (Symflags & object::SymbolRef::SF_FormatSpecific)
 190         continue;
 191       if (!(Symflags & object::SymbolRef::SF_Global))
 192         continue;
 193       if (Symflags & object::SymbolRef::SF_Undefined)
 194         continue;
 195       if (auto EC = S.printName(NameOS))
 196         return EC;
 197       NameOS << '\0';
 198       ++NumSyms;
 199       MemberOffsetRefs.push_back(MemberNum);
 200       print32BE(Out, 0);
 201     }
 202   }
 203   Out << NameOS.str();
 204
 205   if (StartOffset == 0)
 206     return 0;
 207
 208   if (Out.tell() % 2)
 209     Out << '\0';
 210
 211   unsigned Pos = Out.tell();
 212   Out.seek(StartOffset - 12);
 213   printWithSpacePadding(Out, Pos - StartOffset, 10);
 214   Out.seek(StartOffset);
 215   print32BE(Out, NumSyms);
 216   Out.seek(Pos);
 217   return StartOffset + 4;
 218 }
 219
 220 std::pair<StringRef, std::error_code>
 221 llvm::writeArchive(StringRef ArcName,
 222                    std::vector<NewArchiveIterator> &NewMembers,
 223                    bool WriteSymtab) {
 224   SmallString<128> TmpArchive;
 225   int TmpArchiveFD;
 226   if (auto EC = sys::fs::createUniqueFile(ArcName + ".temp-archive-%%%%%%%.a",
 227                                           TmpArchiveFD, TmpArchive))
 228     return std::make_pair(ArcName, EC);
 229
 230   tool_output_file Output(TmpArchive, TmpArchiveFD);
 231   raw_fd_ostream &Out = Output.os();
 232   Out << "!<arch>\n";
 233
 234   std::vector<unsigned> MemberOffsetRefs;
 235
 236   std::vector<std::unique_ptr<MemoryBuffer>> Buffers;
 237   std::vector<MemoryBufferRef> Members;
 238   std::vector<sys::fs::file_status> NewMemberStatus;
 239
 240   for (unsigned I = 0, N = NewMembers.size(); I < N; ++I) {
 241     NewArchiveIterator &Member = NewMembers[I];
 242     MemoryBufferRef MemberRef;
 243
 244     if (Member.isNewMember()) {
 245       StringRef Filename = Member.getNew();
 246       NewMemberStatus.resize(NewMemberStatus.size() + 1);
 247       sys::fs::file_status &Status = NewMemberStatus.back();
 248       ErrorOr<int> FD = Member.getFD(Status);
 249       if (auto EC = FD.getError())
 250         return std::make_pair(Filename, EC);
 251       ErrorOr<std::unique_ptr<MemoryBuffer>> MemberBufferOrErr =
 252           MemoryBuffer::getOpenFile(FD.get(), Filename, Status.getSize(),
 253                                     false);
 254       if (auto EC = MemberBufferOrErr.getError())
 255         return std::make_pair(Filename, EC);
 256       if (close(FD.get()) != 0)
 257         return std::make_pair(Filename,
 258                               std::error_code(errno, std::generic_category()));
 259       Buffers.push_back(std::move(MemberBufferOrErr.get()));
 260       MemberRef = Buffers.back()->getMemBufferRef();
 261     } else {
 262       object::Archive::child_iterator OldMember = Member.getOld();
 263       ErrorOr<MemoryBufferRef> MemberBufferOrErr =
 264           OldMember->getMemoryBufferRef();
 265       if (auto EC = MemberBufferOrErr.getError())
 266         return std::make_pair("", EC);
 267       MemberRef = MemberBufferOrErr.get();
 268     }
 269     Members.push_back(MemberRef);
 270   }
 271
 272   unsigned MemberReferenceOffset = 0;
 273   if (WriteSymtab) {
 274     ErrorOr<unsigned> MemberReferenceOffsetOrErr =
 275         writeSymbolTable(Out, NewMembers, Members, MemberOffsetRefs);
 276     if (auto EC = MemberReferenceOffsetOrErr.getError())
 277       return std::make_pair(ArcName, EC);
 278     MemberReferenceOffset = MemberReferenceOffsetOrErr.get();
 279   }
 280
 281   std::vector<unsigned> StringMapIndexes;
 282   writeStringTable(Out, NewMembers, StringMapIndexes);
 283
 284   unsigned MemberNum = 0;
 285   unsigned LongNameMemberNum = 0;
 286   unsigned NewMemberNum = 0;
 287   std::vector<unsigned> MemberOffset;
 288   for (std::vector<NewArchiveIterator>::iterator I = NewMembers.begin(),
 289                                                  E = NewMembers.end();
 290        I != E; ++I, ++MemberNum) {
 291
 292     unsigned Pos = Out.tell();
 293     MemberOffset.push_back(Pos);
 294
 295     MemoryBufferRef File = Members[MemberNum];
 296     if (I->isNewMember()) {
 297       StringRef FileName = I->getNew();
 298       const sys::fs::file_status &Status = NewMemberStatus[NewMemberNum];
 299       NewMemberNum++;
 300
 301       StringRef Name = sys::path::filename(FileName);
 302       if (Name.size() < 16)
 303         printMemberHeader(Out, Name, Status.getLastModificationTime(),
 304                           Status.getUser(), Status.getGroup(),
 305                           Status.permissions(), Status.getSize());
 306       else
 307         printMemberHeader(Out, StringMapIndexes[LongNameMemberNum++],
 308                           Status.getLastModificationTime(), Status.getUser(),
 309                           Status.getGroup(), Status.permissions(),
 310                           Status.getSize());
 311     } else {
 312       object::Archive::child_iterator OldMember = I->getOld();
 313       StringRef Name = I->getName();
 314
 315       if (Name.size() < 16)
 316         printMemberHeader(Out, Name, OldMember->getLastModified(),
 317                           OldMember->getUID(), OldMember->getGID(),
 318                           OldMember->getAccessMode(), OldMember->getSize());
 319       else
 320         printMemberHeader(Out, StringMapIndexes[LongNameMemberNum++],
 321                           OldMember->getLastModified(), OldMember->getUID(),
 322                           OldMember->getGID(), OldMember->getAccessMode(),
 323                           OldMember->getSize());
 324     }
 325
 326     Out << File.getBuffer();
 327
 328     if (Out.tell() % 2)
 329       Out << '\n';
 330   }
 331
 332   if (MemberReferenceOffset) {
 333     Out.seek(MemberReferenceOffset);
 334     for (unsigned MemberNum : MemberOffsetRefs)
 335       print32BE(Out, MemberOffset[MemberNum]);
 336   }
 337
 338   Output.keep();
 339   Out.close();
 340   sys::fs::rename(TmpArchive, ArcName);
 341   return std::make_pair("", std::error_code());
 342 }