//===- SizeTraits.h -------------------------------------------------------===//
//
//                     The MCLinker Project
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
#ifndef MCLD_ADT_SIZETRAITS_H_
#define MCLD_ADT_SIZETRAITS_H_

#include <llvm/Support/DataTypes.h>
#include <llvm/Support/ELF.h>

namespace mcld {

template <size_t SIZE>
class SizeTraits;

template <>
class SizeTraits<32> {
 public:
  typedef uint32_t Address;
  typedef uint32_t Offset;
  typedef uint32_t Word;
  typedef int32_t SWord;
};

template <>
class SizeTraits<64> {
 public:
  typedef uint64_t Address;
  typedef uint64_t Offset;
  typedef uint64_t Word;
  typedef int64_t SWord;
};

// FIXME: move this to mcld internal ELF header file?
template <size_t SIZE>
class ELFSizeTraits;

template <>
class ELFSizeTraits<32> {
 public:
  typedef llvm::ELF::Elf32_Addr Addr;  // Program address
  typedef llvm::ELF::Elf32_Off Off;    // File offset
  typedef llvm::ELF::Elf32_Half Half;
  typedef llvm::ELF::Elf32_Word Word;
  typedef llvm::ELF::Elf32_Sword Sword;

  typedef llvm::ELF::Elf32_Ehdr Ehdr;
  typedef llvm::ELF::Elf32_Shdr Shdr;
  typedef llvm::ELF::Elf32_Sym Sym;
  typedef llvm::ELF::Elf32_Rel Rel;
  typedef llvm::ELF::Elf32_Rela Rela;
  typedef llvm::ELF::Elf32_Phdr Phdr;
  typedef llvm::ELF::Elf32_Dyn Dyn;
};

template <>
class ELFSizeTraits<64> {
 public:
  typedef llvm::ELF::Elf64_Addr Addr;
  typedef llvm::ELF::Elf64_Off Off;
  typedef llvm::ELF::Elf64_Half Half;
  typedef llvm::ELF::Elf64_Word Word;
  typedef llvm::ELF::Elf64_Sword Sword;
  typedef llvm::ELF::Elf64_Xword Xword;
  typedef llvm::ELF::Elf64_Sxword Sxword;

  typedef llvm::ELF::Elf64_Ehdr Ehdr;
  typedef llvm::ELF::Elf64_Shdr Shdr;
  typedef llvm::ELF::Elf64_Sym Sym;
  typedef llvm::ELF::Elf64_Rel Rel;
  typedef llvm::ELF::Elf64_Rela Rela;
  typedef llvm::ELF::Elf64_Phdr Phdr;
  typedef llvm::ELF::Elf64_Dyn Dyn;
};

/// alignAddress - helper function to align an address with given alignment
/// constraint
///
/// @param pAddr - the address to be aligned
/// @param pAlignConstraint - the alignment used to align the given address
inline void alignAddress(uint64_t& pAddr, uint64_t pAlignConstraint) {
  if (pAlignConstraint != 0)
    pAddr = (pAddr + pAlignConstraint - 1) & ~(pAlignConstraint - 1);
}

template <size_t Constraint>
uint64_t Align(uint64_t pAddress);

template <>
inline uint64_t Align<32>(uint64_t pAddress) {
  return (pAddress + 0x1F) & (~0x1F);
}

template <>
inline uint64_t Align<64>(uint64_t pAddress) {
  return (pAddress + 0x3F) & (~0x3F);
}

#ifdef bswap16
#undef bswap16
#endif
#ifdef bswap32
#undef bswap32
#endif
#ifdef bswap64
#undef bswap64
#endif

/// bswap16 - byte swap 16-bit version
/// @ref binary utilities - elfcpp_swap
inline uint16_t bswap16(uint16_t pData) {
  return ((pData >> 8) & 0xFF) | ((pData & 0xFF) << 8);
}

/// bswap32 - byte swap 32-bit version
/// @ref elfcpp_swap
inline uint32_t bswap32(uint32_t pData) {
  return (((pData & 0xFF000000) >> 24) | ((pData & 0x00FF0000) >> 8) |
          ((pData & 0x0000FF00) << 8) | ((pData & 0x000000FF) << 24));
}

/// bswap64 - byte swap 64-bit version
/// @ref binary utilities - elfcpp_swap
inline uint64_t bswap64(uint64_t pData) {
  return (((pData & 0xFF00000000000000ULL) >> 56) |
          ((pData & 0x00FF000000000000ULL) >> 40) |
          ((pData & 0x0000FF0000000000ULL) >> 24) |
          ((pData & 0x000000FF00000000ULL) >> 8) |
          ((pData & 0x00000000FF000000ULL) << 8) |
          ((pData & 0x0000000000FF0000ULL) << 24) |
          ((pData & 0x000000000000FF00ULL) << 40) |
          ((pData & 0x00000000000000FFULL) << 56));
}

template <size_t SIZE>
typename SizeTraits<SIZE>::Word bswap(typename SizeTraits<SIZE>::Word pData);

template <>
inline SizeTraits<32>::Word bswap<32>(SizeTraits<32>::Word pData) {
  return bswap32(pData);
}

template <>
inline SizeTraits<64>::Word bswap<64>(SizeTraits<64>::Word pData) {
  return bswap64(pData);
}

template <size_t WIDTH>
inline uint64_t signExtend(uint64_t pVal) {
  uint64_t mask = (~((uint64_t)0)) >> (64 - WIDTH);
  uint64_t sign_bit = 1 << (WIDTH - 1);

  return ((pVal & mask) ^ sign_bit) - sign_bit;
}

template <>
inline uint64_t signExtend<64>(uint64_t pVal) {
  return pVal;
}

template <size_t SizeOfStr, typename FieldType>
class StringSizerHelper {
 private:
  char FIELD_TOO_SMALL[SizeOfStr <= FieldType(~0U) ? 1 : -1];

 public:
  enum { Size = SizeOfStr };
};

#define STR_SIZE(str, fieldTy) StringSizerHelper<sizeof(str) - 1, fieldTy>::Size

}  // namespace mcld

#endif  // MCLD_ADT_SIZETRAITS_H_