darling-JavaScriptCore/bytecode/ExpressionRangeInfo.h
2017-08-12 09:48:01 -07:00

109 lines
3.8 KiB
C++

/*
* Copyright (C) 2012-2013, 2016 Apple Inc. All rights reserved.
*
* 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.
*/
#pragma once
#include <wtf/StdLibExtras.h>
namespace JSC {
struct ExpressionRangeInfo {
// Line and column values are encoded in 1 of 3 modes depending on the size
// of their values. These modes are:
//
// 1. FatLine: 22-bit line, 8-bit column.
// 2. FatColumn: 8-bit line, 22-bit column.
// 3. FatLineAndColumn: 32-bit line, 32-bit column.
//
// For the first 2 modes, the line and column will be encoded in the 30-bit
// position field in the ExpressionRangeInfo. For the FatLineAndColumn mode,
// the position field will hold an index into a FatPosition vector which
// holds the FatPosition records with the full 32-bit line and column values.
enum {
FatLineMode,
FatColumnMode,
FatLineAndColumnMode
};
struct FatPosition {
uint32_t line;
uint32_t column;
};
enum {
FatLineModeLineShift = 8,
FatLineModeLineMask = (1 << 22) - 1,
FatLineModeColumnMask = (1 << 8) - 1,
FatColumnModeLineShift = 22,
FatColumnModeLineMask = (1 << 8) - 1,
FatColumnModeColumnMask = (1 << 22) - 1
};
enum {
MaxOffset = (1 << 7) - 1,
MaxDivot = (1 << 25) - 1,
MaxFatLineModeLine = (1 << 22) - 1,
MaxFatLineModeColumn = (1 << 8) - 1,
MaxFatColumnModeLine = (1 << 8) - 1,
MaxFatColumnModeColumn = (1 << 22) - 1
};
void encodeFatLineMode(unsigned line, unsigned column)
{
ASSERT(line <= MaxFatLineModeLine);
ASSERT(column <= MaxFatLineModeColumn);
position = ((line & FatLineModeLineMask) << FatLineModeLineShift | (column & FatLineModeColumnMask));
}
void encodeFatColumnMode(unsigned line, unsigned column)
{
ASSERT(line <= MaxFatColumnModeLine);
ASSERT(column <= MaxFatColumnModeColumn);
position = ((line & FatColumnModeLineMask) << FatColumnModeLineShift | (column & FatColumnModeColumnMask));
}
void decodeFatLineMode(unsigned& line, unsigned& column) const
{
line = (position >> FatLineModeLineShift) & FatLineModeLineMask;
column = position & FatLineModeColumnMask;
}
void decodeFatColumnMode(unsigned& line, unsigned& column) const
{
line = (position >> FatColumnModeLineShift) & FatColumnModeLineMask;
column = position & FatColumnModeColumnMask;
}
uint32_t instructionOffset : 25;
uint32_t startOffset : 7;
uint32_t divotPoint : 25;
uint32_t endOffset : 7;
uint32_t mode : 2;
uint32_t position : 30;
};
} // namespace JSC