| /******************************************************************************* |
| * Copyright (c) 2012 Luaj.org. All rights reserved. |
| * |
| * Permission is hereby granted, free of charge, to any person obtaining a copy |
| * of this software and associated documentation files (the "Software"), to deal |
| * in the Software without restriction, including without limitation the rights |
| * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell |
| * copies of the Software, and to permit persons to whom the Software is |
| * furnished to do so, subject to the following conditions: |
| * |
| * The above copyright notice and this permission notice shall be included in |
| * all copies or substantial portions of the Software. |
| * |
| * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR |
| * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, |
| * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE |
| * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER |
| * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, |
| * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN |
| * THE SOFTWARE. |
| ******************************************************************************/ |
| package org.luaj.vm2.lib; |
| |
| import org.luaj.vm2.LuaTable; |
| import org.luaj.vm2.LuaValue; |
| import org.luaj.vm2.Varargs; |
| |
| /** |
| * Subclass of LibFunction that implements the Lua standard {@code bit32} library. |
| * <p> |
| * Typically, this library is included as part of a call to either |
| * {@link JsePlatform#standardGlobals()} or {@link JmePlatform#standardGlobals()} |
| * <pre> {@code |
| * Globals globals = JsePlatform.standardGlobals(); |
| * System.out.println( globals.get("bit32").get("bnot").call( LuaValue.valueOf(2) ) ); |
| * } </pre> |
| * <p> |
| * To instantiate and use it directly, |
| * link it into your globals table via {@link LuaValue#load(LuaValue)} using code such as: |
| * <pre> {@code |
| * Globals globals = new Globals(); |
| * globals.load(new JseBaseLib()); |
| * globals.load(new PackageLib()); |
| * globals.load(new Bit32Lib()); |
| * System.out.println( globals.get("bit32").get("bnot").call( LuaValue.valueOf(2) ) ); |
| * } </pre> |
| * <p> |
| * This has been implemented to match as closely as possible the behavior in the corresponding library in C. |
| * @see LibFunction |
| * @see JsePlatform |
| * @see JmePlatform |
| * @see <a href="http://www.lua.org/manual/5.2/manual.html#6.7">Lua 5.2 Bitwise Operation Lib Reference</a> |
| */ |
| public class Bit32Lib extends TwoArgFunction { |
| |
| public Bit32Lib() { |
| } |
| |
| public LuaValue call(LuaValue modname, LuaValue env) { |
| LuaTable t = new LuaTable(); |
| bind(t, Bit32LibV.class, new String[] { |
| "band", "bnot", "bor", "btest", "bxor", "extract", "replace" |
| }); |
| bind(t, Bit32Lib2.class, new String[] { |
| "arshift", "lrotate", "lshift", "rrotate", "rshift" |
| }); |
| env.set("bit32", t); |
| env.get("package").get("loaded").set("bit32", t); |
| return t; |
| } |
| |
| static final class Bit32LibV extends VarArgFunction { |
| public Varargs invoke(Varargs args) { |
| switch ( opcode ) { |
| case 0: return Bit32Lib.band( args ); |
| case 1: return Bit32Lib.bnot( args ); |
| case 2: return Bit32Lib.bor( args ); |
| case 3: return Bit32Lib.btest( args ); |
| case 4: return Bit32Lib.bxor( args ); |
| case 5: |
| return Bit32Lib.extract( args.checkint(1), args.checkint(2), args.optint(3, 1) ); |
| case 6: |
| return Bit32Lib.replace( args.checkint(1), args.checkint(2), |
| args.checkint(3), args.optint(4, 1) ); |
| } |
| return NIL; |
| } |
| } |
| |
| static final class Bit32Lib2 extends TwoArgFunction { |
| |
| public LuaValue call(LuaValue arg1, LuaValue arg2) { |
| switch ( opcode ) { |
| case 0: return Bit32Lib.arshift(arg1.checkint(), arg2.checkint()); |
| case 1: return Bit32Lib.lrotate(arg1.checkint(), arg2.checkint()); |
| case 2: return Bit32Lib.lshift(arg1.checkint(), arg2.checkint()); |
| case 3: return Bit32Lib.rrotate(arg1.checkint(), arg2.checkint()); |
| case 4: return Bit32Lib.rshift(arg1.checkint(), arg2.checkint()); |
| } |
| return NIL; |
| } |
| |
| } |
| |
| static LuaValue arshift(int x, int disp) { |
| if (disp >= 0) { |
| return bitsToValue(x >> disp); |
| } else { |
| return bitsToValue(x << -disp); |
| } |
| } |
| |
| static LuaValue rshift(int x, int disp) { |
| if (disp >= 32 || disp <= -32) { |
| return ZERO; |
| } else if (disp >= 0) { |
| return bitsToValue(x >>> disp); |
| } else { |
| return bitsToValue(x << -disp); |
| } |
| } |
| |
| static LuaValue lshift(int x, int disp) { |
| if (disp >= 32 || disp <= -32) { |
| return ZERO; |
| } else if (disp >= 0) { |
| return bitsToValue(x << disp); |
| } else { |
| return bitsToValue(x >>> -disp); |
| } |
| } |
| |
| static Varargs band( Varargs args ) { |
| int result = -1; |
| for ( int i = 1; i <= args.narg(); i++ ) { |
| result &= args.checkint(i); |
| } |
| return bitsToValue( result ); |
| } |
| |
| static Varargs bnot( Varargs args ) { |
| return bitsToValue( ~args.checkint(1) ); |
| } |
| |
| static Varargs bor( Varargs args ) { |
| int result = 0; |
| for ( int i = 1; i <= args.narg(); i++ ) { |
| result |= args.checkint(i); |
| } |
| return bitsToValue( result ); |
| } |
| |
| static Varargs btest( Varargs args ) { |
| int bits = -1; |
| for ( int i = 1; i <= args.narg(); i++ ) { |
| bits &= args.checkint(i); |
| } |
| return valueOf( bits != 0 ); |
| } |
| |
| static Varargs bxor( Varargs args ) { |
| int result = 0; |
| for ( int i = 1; i <= args.narg(); i++ ) { |
| result ^= args.checkint(i); |
| } |
| return bitsToValue( result ); |
| } |
| |
| static LuaValue lrotate(int x, int disp) { |
| if (disp < 0) { |
| return rrotate(x, -disp); |
| } else { |
| disp = disp & 31; |
| return bitsToValue((x << disp) | (x >>> (32 - disp))); |
| } |
| } |
| |
| static LuaValue rrotate(int x, int disp) { |
| if (disp < 0) { |
| return lrotate(x, -disp); |
| } else { |
| disp = disp & 31; |
| return bitsToValue((x >>> disp) | (x << (32 - disp))); |
| } |
| } |
| |
| static LuaValue extract(int n, int field, int width) { |
| if (field < 0) { |
| argerror(2, "field cannot be negative"); |
| } |
| if (width < 0) { |
| argerror(3, "width must be postive"); |
| } |
| if (field + width > 32) { |
| error("trying to access non-existent bits"); |
| } |
| return bitsToValue((n >>> field) & (-1 >>> (32 - width))); |
| } |
| |
| static LuaValue replace(int n, int v, int field, int width) { |
| if (field < 0) { |
| argerror(3, "field cannot be negative"); |
| } |
| if (width < 0) { |
| argerror(4, "width must be postive"); |
| } |
| if (field + width > 32) { |
| error("trying to access non-existent bits"); |
| } |
| int mask = (-1 >>> (32 - width)) << field; |
| n = (n & ~mask) | ((v << field) & mask); |
| return bitsToValue(n); |
| } |
| |
| private static LuaValue bitsToValue( int x ) { |
| return ( x < 0 ) ? valueOf((double) ((long) x & 0xFFFFFFFFL)) : valueOf(x); |
| } |
| } |