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 writeStringTable(raw_fd_ostream &Out,
 128                              ArrayRef<NewArchiveIterator> Members,
 129                              std::vector<unsigned> &StringMapIndexes) {
 130   unsigned StartOffset = 0;
 131   for (ArrayRef<NewArchiveIterator>::iterator I = Members.begin(),
 132                                               E = Members.end();
 133        I != E; ++I) {
 134     StringRef Name = I->getName();
 135     if (Name.size() < 16)
 136       continue;
 137     if (StartOffset == 0) {
 138       printWithSpacePadding(Out, "//", 58);
 139       Out << "`\n";
 140       StartOffset = Out.tell();
 141     }
 142     StringMapIndexes.push_back(Out.tell() - StartOffset);
 143     Out << Name << "/\n";
 144   }
 145   if (StartOffset == 0)
 146     return;
 147   if (Out.tell() % 2)
 148     Out << '\n';
 149   int Pos = Out.tell();
 150   Out.seek(StartOffset - 12);
 151   printWithSpacePadding(Out, Pos - StartOffset, 10);
 152   Out.seek(Pos);
 153 }
 154
 155 // Returns the offset of the first reference to a member offset.
 156 static ErrorOr<unsigned>
 157 writeSymbolTable(raw_fd_ostream &Out, ArrayRef<NewArchiveIterator> Members,
 158                  ArrayRef<MemoryBufferRef> Buffers,
 159                  std::vector<unsigned> &MemberOffsetRefs) {
 160   unsigned StartOffset = 0;
 161   unsigned MemberNum = 0;
 162   std::string NameBuf;
 163   raw_string_ostream NameOS(NameBuf);
 164   unsigned NumSyms = 0;
 165   LLVMContext Context;
 166   for (ArrayRef<NewArchiveIterator>::iterator I = Members.begin(),
 167                                               E = Members.end();
 168        I != E; ++I, ++MemberNum) {
 169     MemoryBufferRef MemberBuffer = Buffers[MemberNum];
 170     ErrorOr<std::unique_ptr<object::SymbolicFile>> ObjOrErr =
 171         object::SymbolicFile::createSymbolicFile(
 172             MemberBuffer, sys::fs::file_magic::unknown, &Context);
 173     if (!ObjOrErr)
 174       continue;  // FIXME: check only for "not an object file" errors.
 175     object::SymbolicFile &Obj = *ObjOrErr.get();
 176
 177     if (!StartOffset) {
 178       printMemberHeader(Out, "", sys::TimeValue::now(), 0, 0, 0, 0);
 179       StartOffset = Out.tell();
 180       print32BE(Out, 0);
 181     }
 182
 183     for (const object::BasicSymbolRef &S : Obj.symbols()) {
 184       uint32_t Symflags = S.getFlags();
 185       if (Symflags & object::SymbolRef::SF_FormatSpecific)
 186         continue;
 187       if (!(Symflags & object::SymbolRef::SF_Global))
 188         continue;
 189       if (Symflags & object::SymbolRef::SF_Undefined)
 190         continue;
 191       if (auto EC = S.printName(NameOS))
 192         return EC;
 193       NameOS << '\0';
 194       ++NumSyms;
 195       MemberOffsetRefs.push_back(MemberNum);
 196       print32BE(Out, 0);
 197     }
 198   }
 199   Out << NameOS.str();
 200
 201   if (StartOffset == 0)
 202     return 0;
 203
 204   if (Out.tell() % 2)
 205     Out << '\0';
 206
 207   unsigned Pos = Out.tell();
 208   Out.seek(StartOffset - 12);
 209   printWithSpacePadding(Out, Pos - StartOffset, 10);
 210   Out.seek(StartOffset);
 211   print32BE(Out, NumSyms);
 212   Out.seek(Pos);
 213   return StartOffset + 4;
 214 }
 215
 216 std::pair<StringRef, std::error_code>
 217 llvm::writeArchive(StringRef ArcName,
 218                    std::vector<NewArchiveIterator> &NewMembers,
 219                    bool WriteSymtab) {
 220   SmallString<128> TmpArchive;
 221   int TmpArchiveFD;
 222   if (auto EC = sys::fs::createUniqueFile(ArcName + ".temp-archive-%%%%%%%.a",
 223                                           TmpArchiveFD, TmpArchive))
 224     return std::make_pair(ArcName, EC);
 225
 226   tool_output_file Output(TmpArchive, TmpArchiveFD);
 227   raw_fd_ostream &Out = Output.os();
 228   Out << "!<arch>\n";
 229
 230   std::vector<unsigned> MemberOffsetRefs;
 231
 232   std::vector<std::unique_ptr<MemoryBuffer>> Buffers;
 233   std::vector<MemoryBufferRef> Members;
 234   std::vector<sys::fs::file_status> NewMemberStatus;
 235
 236   for (unsigned I = 0, N = NewMembers.size(); I < N; ++I) {
 237     NewArchiveIterator &Member = NewMembers[I];
 238     MemoryBufferRef MemberRef;
 239
 240     if (Member.isNewMember()) {
 241       StringRef Filename = Member.getNew();
 242       NewMemberStatus.resize(NewMemberStatus.size() + 1);
 243       sys::fs::file_status &Status = NewMemberStatus.back();
 244       ErrorOr<int> FD = Member.getFD(Status);
 245       if (auto EC = FD.getError())
 246         return std::make_pair(Filename, EC);
 247       ErrorOr<std::unique_ptr<MemoryBuffer>> MemberBufferOrErr =
 248           MemoryBuffer::getOpenFile(FD.get(), Filename, Status.getSize(),
 249                                     false);
 250       if (auto EC = MemberBufferOrErr.getError())
 251         return std::make_pair(Filename, EC);
 252       if (close(FD.get()) != 0)
 253         return std::make_pair(Filename,
 254                               std::error_code(errno, std::generic_category()));
 255       Buffers.push_back(std::move(MemberBufferOrErr.get()));
 256       MemberRef = Buffers.back()->getMemBufferRef();
 257     } else {
 258       object::Archive::child_iterator OldMember = Member.getOld();
 259       ErrorOr<MemoryBufferRef> MemberBufferOrErr =
 260           OldMember->getMemoryBufferRef();
 261       if (auto EC = MemberBufferOrErr.getError())
 262         return std::make_pair("", EC);
 263       MemberRef = MemberBufferOrErr.get();
 264     }
 265     Members.push_back(MemberRef);
 266   }
 267
 268   unsigned MemberReferenceOffset = 0;
 269   if (WriteSymtab) {
 270     ErrorOr<unsigned> MemberReferenceOffsetOrErr =
 271         writeSymbolTable(Out, NewMembers, Members, MemberOffsetRefs);
 272     if (auto EC = MemberReferenceOffsetOrErr.getError())
 273       return std::make_pair(ArcName, EC);
 274     MemberReferenceOffset = MemberReferenceOffsetOrErr.get();
 275   }
 276
 277   std::vector<unsigned> StringMapIndexes;
 278   writeStringTable(Out, NewMembers, StringMapIndexes);
 279
 280   unsigned MemberNum = 0;
 281   unsigned LongNameMemberNum = 0;
 282   unsigned NewMemberNum = 0;
 283   std::vector<unsigned> MemberOffset;
 284   for (std::vector<NewArchiveIterator>::iterator I = NewMembers.begin(),
 285                                                  E = NewMembers.end();
 286        I != E; ++I, ++MemberNum) {
 287
 288     unsigned Pos = Out.tell();
 289     MemberOffset.push_back(Pos);
 290
 291     MemoryBufferRef File = Members[MemberNum];
 292     if (I->isNewMember()) {
 293       StringRef FileName = I->getNew();
 294       const sys::fs::file_status &Status = NewMemberStatus[NewMemberNum];
 295       NewMemberNum++;
 296
 297       StringRef Name = sys::path::filename(FileName);
 298       if (Name.size() < 16)
 299         printMemberHeader(Out, Name, Status.getLastModificationTime(),
 300                           Status.getUser(), Status.getGroup(),
 301                           Status.permissions(), Status.getSize());
 302       else
 303         printMemberHeader(Out, StringMapIndexes[LongNameMemberNum++],
 304                           Status.getLastModificationTime(), Status.getUser(),
 305                           Status.getGroup(), Status.permissions(),
 306                           Status.getSize());
 307     } else {
 308       object::Archive::child_iterator OldMember = I->getOld();
 309       StringRef Name = I->getName();
 310
 311       if (Name.size() < 16)
 312         printMemberHeader(Out, Name, OldMember->getLastModified(),
 313                           OldMember->getUID(), OldMember->getGID(),
 314                           OldMember->getAccessMode(), OldMember->getSize());
 315       else
 316         printMemberHeader(Out, StringMapIndexes[LongNameMemberNum++],
 317                           OldMember->getLastModified(), OldMember->getUID(),
 318                           OldMember->getGID(), OldMember->getAccessMode(),
 319                           OldMember->getSize());
 320     }
 321
 322     Out << File.getBuffer();
 323
 324     if (Out.tell() % 2)
 325       Out << '\n';
 326   }
 327
 328   if (MemberReferenceOffset) {
 329     Out.seek(MemberReferenceOffset);
 330     for (unsigned MemberNum : MemberOffsetRefs)
 331       print32BE(Out, MemberOffset[MemberNum]);
 332   }
 333
 334   Output.keep();
 335   Out.close();
 336   sys::fs::rename(TmpArchive, ArcName);
 337   return std::make_pair("", std::error_code());
 338 }