android_external_webkit/JavaScriptCore/parser/ResultType.h at froyo · madmack/android_external_webkit · GitHub

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* Redistribution and use in source and binary forms, with or without

* modification, are permitted provided that the following conditions

* are met:

* 1. Redistributions of source code must retain the above copyright

* notice, this list of conditions and the following disclaimer.

* 2. Redistributions in binary form must reproduce the above copyright

* notice, this list of conditions and the following disclaimer in the

* documentation and/or other materials provided with the distribution.

* THIS SOFTWARE IS PROVIDED BY APPLE INC. ``AS IS'' AND ANY

* EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE

* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR

* PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL APPLE INC. OR

* CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,

* EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,

* PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR

* PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY

* OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT

* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE

* OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.

#ifndef ResultType_h

#define ResultType_h

namespace JSC {

struct ResultType {

friend struct OperandTypes;

typedef char Type;

static const Type TypeReusable = 1;

static const Type TypeInt32 = 2;

static const Type TypeMaybeNumber = 0x04;

static const Type TypeMaybeString = 0x08;

static const Type TypeMaybeNull = 0x10;

static const Type TypeMaybeBool = 0x20;

static const Type TypeMaybeOther = 0x40;

static const Type TypeBits = TypeMaybeNumber | TypeMaybeString | TypeMaybeNull | TypeMaybeBool | TypeMaybeOther;

explicit ResultType(Type type)

: m_type(type)

{

}

bool isReusable()

{

return m_type & TypeReusable;

}

bool isInt32()

{

return m_type & TypeInt32;

}

bool definitelyIsNumber()

{

return (m_type & TypeBits) == TypeMaybeNumber;

}

bool definitelyIsString()

{

return (m_type & TypeBits) == TypeMaybeString;

}

bool mightBeNumber()

{

return m_type & TypeMaybeNumber;

}

bool isNotNumber()

{

return !mightBeNumber();

}

static ResultType nullType()

{

return ResultType(TypeMaybeNull);

}

static ResultType booleanType()

{

return ResultType(TypeMaybeBool);

}

static ResultType numberType()

{

return ResultType(TypeMaybeNumber);

}

static ResultType numberTypeCanReuse()

{

return ResultType(TypeReusable | TypeMaybeNumber);

}

static ResultType numberTypeCanReuseIsInt32()

{

return ResultType(TypeReusable | TypeInt32 | TypeMaybeNumber);

}

static ResultType stringOrNumberTypeCanReuse()

{

return ResultType(TypeReusable | TypeMaybeNumber | TypeMaybeString);

}

static ResultType stringType()

{

return ResultType(TypeMaybeString);

}

static ResultType unknownType()

{

return ResultType(TypeBits);

}

static ResultType forAdd(ResultType op1, ResultType op2)

{

if (op1.definitelyIsNumber() && op2.definitelyIsNumber())

return numberTypeCanReuse();

if (op1.definitelyIsString() || op2.definitelyIsString())

return stringType();

return stringOrNumberTypeCanReuse();

}

static ResultType forBitOp()

{

return numberTypeCanReuseIsInt32();

}

private:

Type m_type;

};

struct OperandTypes

{

OperandTypes(ResultType first = ResultType::unknownType(), ResultType second = ResultType::unknownType())

{

// We have to initialize one of the int to ensure that

// the entire struct is initialized.

m_u.i = 0;

m_u.rds.first = first.m_type;

m_u.rds.second = second.m_type;

}

union {

struct {

ResultType::Type first;

ResultType::Type second;

} rds;

int i;

} m_u;

ResultType first()

{

return ResultType(m_u.rds.first);

}

ResultType second()

{

return ResultType(m_u.rds.second);

}

int toInt()

{

return m_u.i;

}

static OperandTypes fromInt(int value)

{

OperandTypes types;

types.m_u.i = value;

return types;

}

};

} // namespace JSC

#endif // ResultType_h

android_external_webkit/JavaScriptCore/parser/ResultType.h at froyo · madmack/android_external_webkit · GitHub

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