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/Errc.h"
  22 #include "llvm/Support/ErrorHandling.h"
  23 #include "llvm/Support/Format.h"
  24 #include "llvm/Support/Path.h"
  25 #include "llvm/Support/ToolOutputFile.h"
  26 #include "llvm/Support/raw_ostream.h"
  27
  28 #if !defined(_MSC_VER) && !defined(__MINGW32__)
  29 #include <unistd.h>
  30 #else
  31 #include <io.h>
  32 #endif
  33
  34 using namespace llvm;
  35
  36 NewArchiveIterator::NewArchiveIterator() {}
  37
  38 NewArchiveIterator::NewArchiveIterator(object::Archive::child_iterator I,
  39                                        StringRef Name)
  40     : IsNewMember(false), Name(Name), OldI(I) {}
  41
  42 NewArchiveIterator::NewArchiveIterator(StringRef NewFilename, StringRef Name)
  43     : IsNewMember(true), Name(Name), NewFilename(NewFilename) {}
  44
  45 StringRef NewArchiveIterator::getName() const { return Name; }
  46
  47 bool NewArchiveIterator::isNewMember() const { return IsNewMember; }
  48
  49 object::Archive::child_iterator NewArchiveIterator::getOld() const {
  50   assert(!IsNewMember);
  51   return OldI;
  52 }
  53
  54 StringRef NewArchiveIterator::getNew() const {
  55   assert(IsNewMember);
  56   return NewFilename;
  57 }
  58
  59 llvm::ErrorOr<int>
  60 NewArchiveIterator::getFD(sys::fs::file_status &NewStatus) const {
  61   assert(IsNewMember);
  62   int NewFD;
  63   if (auto EC = sys::fs::openFileForRead(NewFilename, NewFD))
  64     return EC;
  65   assert(NewFD != -1);
  66
  67   if (auto EC = sys::fs::status(NewFD, NewStatus))
  68     return EC;
  69
  70   // Opening a directory doesn't make sense. Let it fail.
  71   // Linux cannot open directories with open(2), although
  72   // cygwin and *bsd can.
  73   if (NewStatus.type() == sys::fs::file_type::directory_file)
  74     return make_error_code(errc::is_a_directory);
  75
  76   return NewFD;
  77 }
  78
  79 template <typename T>
  80 static void printWithSpacePadding(raw_fd_ostream &OS, T Data, unsigned Size,
  81                                   bool MayTruncate = false) {
  82   uint64_t OldPos = OS.tell();
  83   OS << Data;
  84   unsigned SizeSoFar = OS.tell() - OldPos;
  85   if (Size > SizeSoFar) {
  86     unsigned Remaining = Size - SizeSoFar;
  87     for (unsigned I = 0; I < Remaining; ++I)
  88       OS << ' ';
  89   } else if (Size < SizeSoFar) {
  90     assert(MayTruncate && "Data doesn't fit in Size");
  91     // Some of the data this is used for (like UID) can be larger than the
  92     // space available in the archive format. Truncate in that case.
  93     OS.seek(OldPos + Size);
  94   }
  95 }
  96
  97 static void print32BE(raw_fd_ostream &Out, unsigned Val) {
  98   // FIXME: Should use Endian.h here.
  99   for (int I = 3; I >= 0; --I) {
 100     char V = (Val >> (8 * I)) & 0xff;
 101     Out << V;
 102   }
 103 }
 104
 105 static void printRestOfMemberHeader(raw_fd_ostream &Out,
 106                                     const sys::TimeValue &ModTime, unsigned UID,
 107                                     unsigned GID, unsigned Perms,
 108                                     unsigned Size) {
 109   printWithSpacePadding(Out, ModTime.toEpochTime(), 12);
 110   printWithSpacePadding(Out, UID, 6, true);
 111   printWithSpacePadding(Out, GID, 6, true);
 112   printWithSpacePadding(Out, format("%o", Perms), 8);
 113   printWithSpacePadding(Out, Size, 10);
 114   Out << "`\n";
 115 }
 116
 117 static void printMemberHeader(raw_fd_ostream &Out, StringRef Name,
 118                               const sys::TimeValue &ModTime, unsigned UID,
 119                               unsigned GID, unsigned Perms, unsigned Size) {
 120   printWithSpacePadding(Out, Twine(Name) + "/", 16);
 121   printRestOfMemberHeader(Out, ModTime, UID, GID, Perms, Size);
 122 }
 123
 124 static void printMemberHeader(raw_fd_ostream &Out, unsigned NameOffset,
 125                               const sys::TimeValue &ModTime, unsigned UID,
 126                               unsigned GID, unsigned Perms, unsigned Size) {
 127   Out << '/';
 128   printWithSpacePadding(Out, NameOffset, 15);
 129   printRestOfMemberHeader(Out, ModTime, UID, GID, Perms, Size);
 130 }
 131
 132 static void writeStringTable(raw_fd_ostream &Out,
 133                              ArrayRef<NewArchiveIterator> Members,
 134                              std::vector<unsigned> &StringMapIndexes) {
 135   unsigned StartOffset = 0;
 136   for (ArrayRef<NewArchiveIterator>::iterator I = Members.begin(),
 137                                               E = Members.end();
 138        I != E; ++I) {
 139     StringRef Name = I->getName();
 140     if (Name.size() < 16)
 141       continue;
 142     if (StartOffset == 0) {
 143       printWithSpacePadding(Out, "//", 58);
 144       Out << "`\n";
 145       StartOffset = Out.tell();
 146     }
 147     StringMapIndexes.push_back(Out.tell() - StartOffset);
 148     Out << Name << "/\n";
 149   }
 150   if (StartOffset == 0)
 151     return;
 152   if (Out.tell() % 2)
 153     Out << '\n';
 154   int Pos = Out.tell();
 155   Out.seek(StartOffset - 12);
 156   printWithSpacePadding(Out, Pos - StartOffset, 10);
 157   Out.seek(Pos);
 158 }
 159
 160 // Returns the offset of the first reference to a member offset.
 161 static ErrorOr<unsigned>
 162 writeSymbolTable(raw_fd_ostream &Out, ArrayRef<NewArchiveIterator> Members,
 163                  ArrayRef<MemoryBufferRef> Buffers,
 164                  std::vector<unsigned> &MemberOffsetRefs) {
 165   unsigned StartOffset = 0;
 166   unsigned MemberNum = 0;
 167   std::string NameBuf;
 168   raw_string_ostream NameOS(NameBuf);
 169   unsigned NumSyms = 0;
 170   LLVMContext Context;
 171   for (ArrayRef<NewArchiveIterator>::iterator I = Members.begin(),
 172                                               E = Members.end();
 173        I != E; ++I, ++MemberNum) {
 174     MemoryBufferRef MemberBuffer = Buffers[MemberNum];
 175     ErrorOr<std::unique_ptr<object::SymbolicFile>> ObjOrErr =
 176         object::SymbolicFile::createSymbolicFile(
 177             MemberBuffer, sys::fs::file_magic::unknown, &Context);
 178     if (!ObjOrErr)
 179       continue;  // FIXME: check only for "not an object file" errors.
 180     object::SymbolicFile &Obj = *ObjOrErr.get();
 181
 182     if (!StartOffset) {
 183       printMemberHeader(Out, "", sys::TimeValue::now(), 0, 0, 0, 0);
 184       StartOffset = Out.tell();
 185       print32BE(Out, 0);
 186     }
 187
 188     for (const object::BasicSymbolRef &S : Obj.symbols()) {
 189       uint32_t Symflags = S.getFlags();
 190       if (Symflags & object::SymbolRef::SF_FormatSpecific)
 191         continue;
 192       if (!(Symflags & object::SymbolRef::SF_Global))
 193         continue;
 194       if (Symflags & object::SymbolRef::SF_Undefined)
 195         continue;
 196       if (auto EC = S.printName(NameOS))
 197         return EC;
 198       NameOS << '\0';
 199       ++NumSyms;
 200       MemberOffsetRefs.push_back(MemberNum);
 201       print32BE(Out, 0);
 202     }
 203   }
 204   Out << NameOS.str();
 205
 206   if (StartOffset == 0)
 207     return 0;
 208
 209   if (Out.tell() % 2)
 210     Out << '\0';
 211
 212   unsigned Pos = Out.tell();
 213   Out.seek(StartOffset - 12);
 214   printWithSpacePadding(Out, Pos - StartOffset, 10);
 215   Out.seek(StartOffset);
 216   print32BE(Out, NumSyms);
 217   Out.seek(Pos);
 218   return StartOffset + 4;
 219 }
 220
 221 std::pair<StringRef, std::error_code>
 222 llvm::writeArchive(StringRef ArcName,
 223                    std::vector<NewArchiveIterator> &NewMembers,
 224                    bool WriteSymtab) {
 225   SmallString<128> TmpArchive;
 226   int TmpArchiveFD;
 227   if (auto EC = sys::fs::createUniqueFile(ArcName + ".temp-archive-%%%%%%%.a",
 228                                           TmpArchiveFD, TmpArchive))
 229     return std::make_pair(ArcName, EC);
 230
 231   tool_output_file Output(TmpArchive, TmpArchiveFD);
 232   raw_fd_ostream &Out = Output.os();
 233   Out << "!<arch>\n";
 234
 235   std::vector<unsigned> MemberOffsetRefs;
 236
 237   std::vector<std::unique_ptr<MemoryBuffer>> Buffers;
 238   std::vector<MemoryBufferRef> Members;
 239   std::vector<sys::fs::file_status> NewMemberStatus;
 240
 241   for (unsigned I = 0, N = NewMembers.size(); I < N; ++I) {
 242     NewArchiveIterator &Member = NewMembers[I];
 243     MemoryBufferRef MemberRef;
 244
 245     if (Member.isNewMember()) {
 246       StringRef Filename = Member.getNew();
 247       NewMemberStatus.resize(NewMemberStatus.size() + 1);
 248       sys::fs::file_status &Status = NewMemberStatus.back();
 249       ErrorOr<int> FD = Member.getFD(Status);
 250       if (auto EC = FD.getError())
 251         return std::make_pair(Filename, EC);
 252       ErrorOr<std::unique_ptr<MemoryBuffer>> MemberBufferOrErr =
 253           MemoryBuffer::getOpenFile(FD.get(), Filename, Status.getSize(),
 254                                     false);
 255       if (auto EC = MemberBufferOrErr.getError())
 256         return std::make_pair(Filename, EC);
 257       if (close(FD.get()) != 0)
 258         return std::make_pair(Filename,
 259                               std::error_code(errno, std::generic_category()));
 260       Buffers.push_back(std::move(MemberBufferOrErr.get()));
 261       MemberRef = Buffers.back()->getMemBufferRef();
 262     } else {
 263       object::Archive::child_iterator OldMember = Member.getOld();
 264       ErrorOr<MemoryBufferRef> MemberBufferOrErr =
 265           OldMember->getMemoryBufferRef();
 266       if (auto EC = MemberBufferOrErr.getError())
 267         return std::make_pair("", EC);
 268       MemberRef = MemberBufferOrErr.get();
 269     }
 270     Members.push_back(MemberRef);
 271   }
 272
 273   unsigned MemberReferenceOffset = 0;
 274   if (WriteSymtab) {
 275     ErrorOr<unsigned> MemberReferenceOffsetOrErr =
 276         writeSymbolTable(Out, NewMembers, Members, MemberOffsetRefs);
 277     if (auto EC = MemberReferenceOffsetOrErr.getError())
 278       return std::make_pair(ArcName, EC);
 279     MemberReferenceOffset = MemberReferenceOffsetOrErr.get();
 280   }
 281
 282   std::vector<unsigned> StringMapIndexes;
 283   writeStringTable(Out, NewMembers, StringMapIndexes);
 284
 285   unsigned MemberNum = 0;
 286   unsigned LongNameMemberNum = 0;
 287   unsigned NewMemberNum = 0;
 288   std::vector<unsigned> MemberOffset;
 289   for (std::vector<NewArchiveIterator>::iterator I = NewMembers.begin(),
 290                                                  E = NewMembers.end();
 291        I != E; ++I, ++MemberNum) {
 292
 293     unsigned Pos = Out.tell();
 294     MemberOffset.push_back(Pos);
 295
 296     MemoryBufferRef File = Members[MemberNum];
 297     if (I->isNewMember()) {
 298       StringRef FileName = I->getNew();
 299       const sys::fs::file_status &Status = NewMemberStatus[NewMemberNum];
 300       NewMemberNum++;
 301
 302       StringRef Name = sys::path::filename(FileName);
 303       if (Name.size() < 16)
 304         printMemberHeader(Out, Name, Status.getLastModificationTime(),
 305                           Status.getUser(), Status.getGroup(),
 306                           Status.permissions(), Status.getSize());
 307       else
 308         printMemberHeader(Out, StringMapIndexes[LongNameMemberNum++],
 309                           Status.getLastModificationTime(), Status.getUser(),
 310                           Status.getGroup(), Status.permissions(),
 311                           Status.getSize());
 312     } else {
 313       object::Archive::child_iterator OldMember = I->getOld();
 314       StringRef Name = I->getName();
 315
 316       if (Name.size() < 16)
 317         printMemberHeader(Out, Name, OldMember->getLastModified(),
 318                           OldMember->getUID(), OldMember->getGID(),
 319                           OldMember->getAccessMode(), OldMember->getSize());
 320       else
 321         printMemberHeader(Out, StringMapIndexes[LongNameMemberNum++],
 322                           OldMember->getLastModified(), OldMember->getUID(),
 323                           OldMember->getGID(), OldMember->getAccessMode(),
 324                           OldMember->getSize());
 325     }
 326
 327     Out << File.getBuffer();
 328
 329     if (Out.tell() % 2)
 330       Out << '\n';
 331   }
 332
 333   if (MemberReferenceOffset) {
 334     Out.seek(MemberReferenceOffset);
 335     for (unsigned MemberNum : MemberOffsetRefs)
 336       print32BE(Out, MemberOffset[MemberNum]);
 337   }
 338
 339   Output.keep();
 340   Out.close();
 341   sys::fs::rename(TmpArchive, ArcName);
 342   return std::make_pair("", std::error_code());
 343 }