src/llvm/tools/dsymutil/BinaryHolder.cpp

   1 //===-- BinaryHolder.cpp --------------------------------------------------===//
   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 program is a utility that aims to be a dropin replacement for
  11 // Darwin's dsymutil.
  12 //
  13 //===----------------------------------------------------------------------===//
  14
  15 #include "BinaryHolder.h"
  16 #include "llvm/Support/raw_ostream.h"
  17
  18 namespace llvm {
  19 namespace dsymutil {
  20
  21 ErrorOr<MemoryBufferRef>
  22 BinaryHolder::GetMemoryBufferForFile(StringRef Filename) {
  23   if (Verbose)
  24     outs() << "trying to open '" << Filename << "'\n";
  25
  26   // Try that first as it doesn't involve any filesystem access.
  27   if (auto ErrOrArchiveMember = GetArchiveMemberBuffer(Filename))
  28     return *ErrOrArchiveMember;
  29
  30   // If the name ends with a closing paren, there is a huge chance
  31   // it is an archive member specification.
  32   if (Filename.endswith(")"))
  33     if (auto ErrOrArchiveMember = MapArchiveAndGetMemberBuffer(Filename))
  34       return *ErrOrArchiveMember;
  35
  36   // Otherwise, just try opening a standard file. If this is an
  37   // archive member specifiaction and any of the above didn't handle it
  38   // (either because the archive is not there anymore, or because the
  39   // archive doesn't contain the requested member), this will still
  40   // provide a sensible error message.
  41   auto ErrOrFile = MemoryBuffer::getFileOrSTDIN(Filename);
  42   if (auto Err = ErrOrFile.getError())
  43     return Err;
  44
  45   if (Verbose)
  46     outs() << "\tloaded file.\n";
  47   CurrentArchive.reset();
  48   CurrentMemoryBuffer = std::move(ErrOrFile.get());
  49   return CurrentMemoryBuffer->getMemBufferRef();
  50 }
  51
  52 ErrorOr<MemoryBufferRef>
  53 BinaryHolder::GetArchiveMemberBuffer(StringRef Filename) {
  54   if (!CurrentArchive)
  55     return make_error_code(errc::no_such_file_or_directory);
  56
  57   StringRef CurArchiveName = CurrentArchive->getFileName();
  58   if (!Filename.startswith(Twine(CurArchiveName, "(").str()))
  59     return make_error_code(errc::no_such_file_or_directory);
  60
  61   // Remove the archive name and the parens around the archive member name.
  62   Filename = Filename.substr(CurArchiveName.size() + 1).drop_back();
  63
  64   for (const auto &Child : CurrentArchive->children()) {
  65     if (auto NameOrErr = Child.getName())
  66       if (*NameOrErr == Filename) {
  67         if (Verbose)
  68           outs() << "\tfound member in current archive.\n";
  69         return Child.getMemoryBufferRef();
  70       }
  71   }
  72
  73   return make_error_code(errc::no_such_file_or_directory);
  74 }
  75
  76 ErrorOr<MemoryBufferRef>
  77 BinaryHolder::MapArchiveAndGetMemberBuffer(StringRef Filename) {
  78   StringRef ArchiveFilename = Filename.substr(0, Filename.find('('));
  79
  80   auto ErrOrBuff = MemoryBuffer::getFileOrSTDIN(ArchiveFilename);
  81   if (auto Err = ErrOrBuff.getError())
  82     return Err;
  83
  84   if (Verbose)
  85     outs() << "\topened new archive '" << ArchiveFilename << "'\n";
  86   auto ErrOrArchive = object::Archive::create((*ErrOrBuff)->getMemBufferRef());
  87   if (auto Err = ErrOrArchive.getError())
  88     return Err;
  89
  90   CurrentArchive = std::move(*ErrOrArchive);
  91   CurrentMemoryBuffer = std::move(*ErrOrBuff);
  92
  93   return GetArchiveMemberBuffer(Filename);
  94 }
  95
  96 ErrorOr<const object::ObjectFile &>
  97 BinaryHolder::GetObjectFile(StringRef Filename) {
  98   auto ErrOrMemBufferRef = GetMemoryBufferForFile(Filename);
  99   if (auto Err = ErrOrMemBufferRef.getError())
 100     return Err;
 101
 102   auto ErrOrObjectFile =
 103       object::ObjectFile::createObjectFile(*ErrOrMemBufferRef);
 104   if (auto Err = ErrOrObjectFile.getError())
 105     return Err;
 106
 107   CurrentObjectFile = std::move(*ErrOrObjectFile);
 108   return *CurrentObjectFile;
 109 }
 110 }
 111 }