//===--- APNumericStorage.h - Store APInt/APFloat in ASTContext -*- C++ -*-===//

//

// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.

// See https://llvm.org/LICENSE.txt for license information.

// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception

//

//===----------------------------------------------------------------------===//

#ifndef LLVM_CLANG_AST_APNUMERICSTORAGE_H

#define LLVM_CLANG_AST_APNUMERICSTORAGE_H

#include "llvm/ADT/APFloat.h"

#include "llvm/ADT/APInt.h"

namespace clang {

class ASTContext;

/// Used by IntegerLiteral/FloatingLiteral/EnumConstantDecl to store the

/// numeric without leaking memory.

///

/// For large floats/integers, APFloat/APInt will allocate memory from the heap

/// to represent these numbers.  Unfortunately, when we use a BumpPtrAllocator

/// to allocate IntegerLiteral/FloatingLiteral nodes the memory associated with

/// the APFloat/APInt values will never get freed. APNumericStorage uses

/// ASTContext's allocator for memory allocation.

class APNumericStorage {

  union {

    uint64_t VAL;   ///< Used to store the <= 64 bits integer value.

    uint64_t *pVal; ///< Used to store the >64 bits integer value.

  };

  unsigned BitWidth;

  bool hasAllocation() const { return llvm::APInt::getNumWords(BitWidth) > 1; }

  APNumericStorage(const APNumericStorage &) = delete;

  void operator=(const APNumericStorage &) = delete;

protected:

  APNumericStorage() : VAL(0), BitWidth(0) {}

  llvm::APInt getIntValue() const {

    unsigned NumWords = llvm::APInt::getNumWords(BitWidth);

    if (NumWords > 1)

      return llvm::APInt(BitWidth, NumWords, pVal);

    else

      return llvm::APInt(BitWidth, VAL);

  }

  void setIntValue(const ASTContext &C, const llvm::APInt &Val);

};

class APIntStorage : private APNumericStorage {

public:

  llvm::APInt getValue() const { return getIntValue(); }

  void setValue(const ASTContext &C, const llvm::APInt &Val) {

    setIntValue(C, Val);

  }

};

class APFloatStorage : private APNumericStorage {

public:

  llvm::APFloat getValue(const llvm::fltSemantics &Semantics) const {

    return llvm::APFloat(Semantics, getIntValue());

  }

  void setValue(const ASTContext &C, const llvm::APFloat &Val) {

    setIntValue(C, Val.bitcastToAPInt());

  }

};

} // end namespace clang

#endif // LLVM_CLANG_AST_APNUMERICSTORAGE_H