llvm/lib/Object/ELFObjectFile.cpp
Michael J. Spencer 081a1941b5 [Object] Split the ELF interface into 3 parts.
* ELFTypes.h contains template magic for defining types based on endianess, size, and alignment.
* ELFFile.h defines the ELFFile class which provides low level ELF specific access.
* ELFObjectFile.h contains ELFObjectFile which uses ELFFile to implement the ObjectFile interface.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@188022 91177308-0d34-0410-b5e6-96231b3b80d8
2013-08-08 22:27:13 +00:00

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//===- 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;
// Creates an in-memory object-file by default: createELFObjectFile(Buffer)
ObjectFile *ObjectFile::createELFObjectFile(MemoryBuffer *Object) {
std::pair<unsigned char, unsigned char> Ident = getElfArchType(Object);
error_code ec;
std::size_t MaxAlignment =
1ULL << countTrailingZeros(uintptr_t(Object->getBufferStart()));
if (Ident.first == ELF::ELFCLASS32 && Ident.second == ELF::ELFDATA2LSB)
#if !LLVM_IS_UNALIGNED_ACCESS_FAST
if (MaxAlignment >= 4)
return new ELFObjectFile<ELFType<support::little, 4, false> >(Object, ec);
else
#endif
if (MaxAlignment >= 2)
return new ELFObjectFile<ELFType<support::little, 2, false> >(Object, ec);
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)
return new ELFObjectFile<ELFType<support::big, 4, false> >(Object, ec);
else
#endif
if (MaxAlignment >= 2)
return new ELFObjectFile<ELFType<support::big, 2, false> >(Object, ec);
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)
return new ELFObjectFile<ELFType<support::big, 8, true> >(Object, ec);
else
#endif
if (MaxAlignment >= 2)
return new ELFObjectFile<ELFType<support::big, 2, true> >(Object, ec);
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)
return new ELFObjectFile<ELFType<support::little, 8, true> >(Object, ec);
else
#endif
if (MaxAlignment >= 2)
return new ELFObjectFile<ELFType<support::little, 2, true> >(Object, ec);
else
llvm_unreachable("Invalid alignment for ELF file!");
}
report_fatal_error("Buffer is not an ELF object file!");
}
} // end namespace llvm