llvm/lib/Object/ELFObjectFile.cpp
Rafael Espindola 584fe2db6a Make ObjectFile ownership of the MemoryBuffer optional.
This allows llvm-ar to mmap the input files only once.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@200040 91177308-0d34-0410-b5e6-96231b3b80d8
2014-01-24 21:32:21 +00:00

86 lines
3.1 KiB
C++

//===- ELFObjectFile.cpp - ELF object file implementation -------*- C++ -*-===//
//
// The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
//
// Part of the ELFObjectFile class implementation.
//
//===----------------------------------------------------------------------===//
#include "llvm/Object/ELFObjectFile.h"
#include "llvm/Support/MathExtras.h"
namespace llvm {
using namespace object;
ErrorOr<ObjectFile *> ObjectFile::createELFObjectFile(MemoryBuffer *Obj,
bool BufferOwned) {
std::pair<unsigned char, unsigned char> Ident = getElfArchType(Obj);
std::size_t MaxAlignment =
1ULL << countTrailingZeros(uintptr_t(Obj->getBufferStart()));
error_code EC;
OwningPtr<ObjectFile> R;
if (Ident.first == ELF::ELFCLASS32 && Ident.second == ELF::ELFDATA2LSB)
#if !LLVM_IS_UNALIGNED_ACCESS_FAST
if (MaxAlignment >= 4)
R.reset(new ELFObjectFile<ELFType<support::little, 4, false> >(
Obj, EC, BufferOwned));
else
#endif
if (MaxAlignment >= 2)
R.reset(new ELFObjectFile<ELFType<support::little, 2, false> >(
Obj, EC, BufferOwned));
else
llvm_unreachable("Invalid alignment for ELF file!");
else if (Ident.first == ELF::ELFCLASS32 && Ident.second == ELF::ELFDATA2MSB)
#if !LLVM_IS_UNALIGNED_ACCESS_FAST
if (MaxAlignment >= 4)
R.reset(new ELFObjectFile<ELFType<support::big, 4, false> >(Obj, EC,
BufferOwned));
else
#endif
if (MaxAlignment >= 2)
R.reset(new ELFObjectFile<ELFType<support::big, 2, false> >(Obj, EC,
BufferOwned));
else
llvm_unreachable("Invalid alignment for ELF file!");
else if (Ident.first == ELF::ELFCLASS64 && Ident.second == ELF::ELFDATA2MSB)
#if !LLVM_IS_UNALIGNED_ACCESS_FAST
if (MaxAlignment >= 8)
R.reset(new ELFObjectFile<ELFType<support::big, 8, true> >(Obj, EC,
BufferOwned));
else
#endif
if (MaxAlignment >= 2)
R.reset(new ELFObjectFile<ELFType<support::big, 2, true> >(Obj, EC,
BufferOwned));
else
llvm_unreachable("Invalid alignment for ELF file!");
else if (Ident.first == ELF::ELFCLASS64 && Ident.second == ELF::ELFDATA2LSB) {
#if !LLVM_IS_UNALIGNED_ACCESS_FAST
if (MaxAlignment >= 8)
R.reset(new ELFObjectFile<ELFType<support::little, 8, true> >(
Obj, EC, BufferOwned));
else
#endif
if (MaxAlignment >= 2)
R.reset(new ELFObjectFile<ELFType<support::little, 2, true> >(
Obj, EC, BufferOwned));
else
llvm_unreachable("Invalid alignment for ELF file!");
}
else
report_fatal_error("Buffer is not an ELF object file!");
if (EC)
return EC;
return R.take();
}
} // end namespace llvm