//===-- llvm/Support/Win64EH.h ---Win64 EH Constants-------------*- C++ -*-===//
//
//                     The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
//
// This file contains constants and structures used for implementing
// exception handling on Win64 platforms. For more information, see
// http://msdn.microsoft.com/en-us/library/1eyas8tf.aspx
//
//===----------------------------------------------------------------------===//

#ifndef LLVM_SUPPORT_WIN64EH_H
#define LLVM_SUPPORT_WIN64EH_H

namespace llvm {
namespace Win64EH {

/// UnwindOpcodes - Enumeration whose values specify a single operation in
/// the prolog of a function.
enum UnwindOpcodes {
  UOP_PushNonVol = 0,
  UOP_AllocLarge,
  UOP_AllocSmall,
  UOP_SetFPReg,
  UOP_SaveNonVol,
  UOP_SaveNonVolBig,
  UOP_SaveXMM128,
  UOP_SaveXMM128Big,
  UOP_PushMachFrame
};

/// UnwindCode - This union describes a single operation in a function prolog,
/// or part thereof.
union UnwindCode {
  struct {
    uint8_t codeOffset;
    uint8_t unwindOp:4,
            opInfo:4;
  };
  uint16_t frameOffset;
};

enum {
  /// UNW_ExceptionHandler - Specifies that this function has an exception
  /// handler.
  UNW_ExceptionHandler = 0x01,
  /// UNW_TerminateHandler - Specifies that this function has a termination
  /// handler.
  UNW_TerminateHandler = 0x02,
  /// UNW_ChainInfo - Specifies that this UnwindInfo structure is chained to
  /// another one.
  UNW_ChainInfo = 0x04
};

/// UnwindInfo - An entry in the exception table.
struct UnwindInfo {
  uint8_t version:3,
          flags:5;
  uint8_t prologSize;
  uint8_t numCodes;
  uint8_t frameRegister:4,
          frameOffset:4;
  UnwindCode unwindCodes[1];
};

inline UnwindCode &getUnwindCodeEntry(UnwindInfo &info, uint32_t index) {
  return info.unwindCodes[index];
}
inline void *getLanguageSpecificData(UnwindInfo &info) {
  return reinterpret_cast<void *>(&getUnwindCodeEntry(info,info.numCodes+1)&~1);
}
inline uint64_t getLanguageSpecificHandlerOffset(UnwindInfo &info) {
  return *reinterpret_cast<uint64_t *>(getLangaugeSpecificData(info));
}
inline void setLanguageSpecificHandlerOffset(UnwindInfo &info, uint64_t offset){
  *reinterpret_cast<uint64_t *>(getLanguageSpecificData(info)) = offset;
}
inline uint64_t getChainedFunctionEntryOffset(UnwindInfo &info) {
  return *reinterpret_cast<uint64_t *>(getLanguageSpecificData(info));
}
inline void setChainedFunctionEntryOffset(UnwindInfo &info, uint64_t offset) {
  *reinterpret_cast<uint64_t *>(getLanguageSpecificData(info)) = offset;
}
inline void *getExceptionData(UnwindInfo &info) {
  return reinterpret_cast<void *>(reinterpret_cast<uint64_t *>(
                                              getLanguageSpecificData(info))+1);
}

} // End of namespace Win64EH
} // End of namespace llvm

#endif