    001/*
    002 * Licensed to the Apache Software Foundation (ASF) under one
    003 * or more contributor license agreements.  See the NOTICE file
    004 * distributed with this work for additional information
    005 * regarding copyright ownership.  The ASF licenses this file
    006 * to you under the Apache License, Version 2.0 (the
    007 * "License"); you may not use this file except in compliance
    008 * with the License.  You may obtain a copy of the License at
    009 *
    010 *   https://www.apache.org/licenses/LICENSE-2.0
    011 *
    012 * Unless required by applicable law or agreed to in writing,
    013 * software distributed under the License is distributed on an
    014 * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
    015 * KIND, either express or implied.  See the License for the
    016 * specific language governing permissions and limitations
    017 * under the License.
    018 */
    019
    020package org.apache.bcel.generic;
    021
    022import org.apache.bcel.Const;
    023
    024/**
    025 * Contains shareable instruction objects.
    026 * <p>
    027 * In order to save memory you can use some instructions multiply, since they have an immutable state and are directly derived from Instruction. I.e. they have
    028 * no instance fields that could be changed. Since some of these instructions like ICONST_0 occur very frequently this can save a lot of time and space. This
    029 * feature is an adaptation of the FlyWeight design pattern, we just use an array instead of a factory.
    030 * </p>
    031 * <p>
    032 * The Instructions can also accessed directly under their names, so it's possible to write il.append(Instruction.ICONST_0);
    033 * </p>
    034 */
    035public final class InstructionConst {
    036
    037    /**
    038     * Predefined instruction objects. NOTE these are not currently immutable, because Instruction has mutable protected fields opcode and length.
    039     */
    040
    041    /** NOP instruction. */
    042    public static final Instruction NOP = new NOP();
    043
    044    /** ACONST_NULL instruction. */
    045    public static final Instruction ACONST_NULL = new ACONST_NULL();
    046
    047    /** ICONST_M1 instruction. */
    048    public static final Instruction ICONST_M1 = new ICONST(-1);
    049
    050    /** ICONST_0 instruction. */
    051    public static final Instruction ICONST_0 = new ICONST(0);
    052
    053    /** ICONST_1 instruction. */
    054    public static final Instruction ICONST_1 = new ICONST(1);
    055
    056    /** ICONST_2 instruction. */
    057    public static final Instruction ICONST_2 = new ICONST(2);
    058
    059    /** ICONST_3 instruction. */
    060    public static final Instruction ICONST_3 = new ICONST(3);
    061
    062    /** ICONST_4 instruction. */
    063    public static final Instruction ICONST_4 = new ICONST(4);
    064
    065    /** ICONST_5 instruction. */
    066    public static final Instruction ICONST_5 = new ICONST(5);
    067
    068    /** LCONST_0 instruction. */
    069    public static final Instruction LCONST_0 = new LCONST(0);
    070
    071    /** LCONST_1 instruction. */
    072    public static final Instruction LCONST_1 = new LCONST(1);
    073
    074    /** FCONST_0 instruction. */
    075    public static final Instruction FCONST_0 = new FCONST(0);
    076
    077    /** FCONST_1 instruction. */
    078    public static final Instruction FCONST_1 = new FCONST(1);
    079
    080    /** FCONST_2 instruction. */
    081    public static final Instruction FCONST_2 = new FCONST(2);
    082
    083    /** DCONST_0 instruction. */
    084    public static final Instruction DCONST_0 = new DCONST(0);
    085
    086    /** DCONST_1 instruction. */
    087    public static final Instruction DCONST_1 = new DCONST(1);
    088
    089    /** IALOAD instruction. */
    090    public static final ArrayInstruction IALOAD = new IALOAD();
    091
    092    /** LALOAD instruction. */
    093    public static final ArrayInstruction LALOAD = new LALOAD();
    094
    095    /** FALOAD instruction. */
    096    public static final ArrayInstruction FALOAD = new FALOAD();
    097
    098    /** DALOAD instruction. */
    099    public static final ArrayInstruction DALOAD = new DALOAD();
    100
    101    /** AALOAD instruction. */
    102    public static final ArrayInstruction AALOAD = new AALOAD();
    103
    104    /** BALOAD instruction. */
    105    public static final ArrayInstruction BALOAD = new BALOAD();
    106
    107    /** CALOAD instruction. */
    108    public static final ArrayInstruction CALOAD = new CALOAD();
    109
    110    /** SALOAD instruction. */
    111    public static final ArrayInstruction SALOAD = new SALOAD();
    112
    113    /** IASTORE instruction. */
    114    public static final ArrayInstruction IASTORE = new IASTORE();
    115
    116    /** LASTORE instruction. */
    117    public static final ArrayInstruction LASTORE = new LASTORE();
    118
    119    /** FASTORE instruction. */
    120    public static final ArrayInstruction FASTORE = new FASTORE();
    121
    122    /** DASTORE instruction. */
    123    public static final ArrayInstruction DASTORE = new DASTORE();
    124
    125    /** AASTORE instruction. */
    126    public static final ArrayInstruction AASTORE = new AASTORE();
    127
    128    /** BASTORE instruction. */
    129    public static final ArrayInstruction BASTORE = new BASTORE();
    130
    131    /** CASTORE instruction. */
    132    public static final ArrayInstruction CASTORE = new CASTORE();
    133
    134    /** SASTORE instruction. */
    135    public static final ArrayInstruction SASTORE = new SASTORE();
    136
    137    /** POP instruction. */
    138    public static final StackInstruction POP = new POP();
    139
    140    /** POP2 instruction. */
    141    public static final StackInstruction POP2 = new POP2();
    142
    143    /** DUP instruction. */
    144    public static final StackInstruction DUP = new DUP();
    145
    146    /** DUP_X1 instruction. */
    147    public static final StackInstruction DUP_X1 = new DUP_X1();
    148
    149    /** DUP_X2 instruction. */
    150    public static final StackInstruction DUP_X2 = new DUP_X2();
    151
    152    /** DUP2 instruction. */
    153    public static final StackInstruction DUP2 = new DUP2();
    154
    155    /** DUP2_X1 instruction. */
    156    public static final StackInstruction DUP2_X1 = new DUP2_X1();
    157
    158    /** DUP2_X2 instruction. */
    159    public static final StackInstruction DUP2_X2 = new DUP2_X2();
    160
    161    /** SWAP instruction. */
    162    public static final StackInstruction SWAP = new SWAP();
    163
    164    /** IADD instruction. */
    165    public static final ArithmeticInstruction IADD = new IADD();
    166
    167    /** LADD instruction. */
    168    public static final ArithmeticInstruction LADD = new LADD();
    169
    170    /** FADD instruction. */
    171    public static final ArithmeticInstruction FADD = new FADD();
    172
    173    /** DADD instruction. */
    174    public static final ArithmeticInstruction DADD = new DADD();
    175
    176    /** ISUB instruction. */
    177    public static final ArithmeticInstruction ISUB = new ISUB();
    178
    179    /** LSUB instruction. */
    180    public static final ArithmeticInstruction LSUB = new LSUB();
    181
    182    /** FSUB instruction. */
    183    public static final ArithmeticInstruction FSUB = new FSUB();
    184
    185    /** DSUB instruction. */
    186    public static final ArithmeticInstruction DSUB = new DSUB();
    187
    188    /** IMUL instruction. */
    189    public static final ArithmeticInstruction IMUL = new IMUL();
    190
    191    /** LMUL instruction. */
    192    public static final ArithmeticInstruction LMUL = new LMUL();
    193
    194    /** FMUL instruction. */
    195    public static final ArithmeticInstruction FMUL = new FMUL();
    196
    197    /** DMUL instruction. */
    198    public static final ArithmeticInstruction DMUL = new DMUL();
    199
    200    /** IDIV instruction. */
    201    public static final ArithmeticInstruction IDIV = new IDIV();
    202
    203    /** LDIV instruction. */
    204    public static final ArithmeticInstruction LDIV = new LDIV();
    205
    206    /** FDIV instruction. */
    207    public static final ArithmeticInstruction FDIV = new FDIV();
    208
    209    /** DDIV instruction. */
    210    public static final ArithmeticInstruction DDIV = new DDIV();
    211
    212    /** IREM instruction. */
    213    public static final ArithmeticInstruction IREM = new IREM();
    214
    215    /** LREM instruction. */
    216    public static final ArithmeticInstruction LREM = new LREM();
    217
    218    /** FREM instruction. */
    219    public static final ArithmeticInstruction FREM = new FREM();
    220
    221    /** DREM instruction. */
    222    public static final ArithmeticInstruction DREM = new DREM();
    223
    224    /** INEG instruction. */
    225    public static final ArithmeticInstruction INEG = new INEG();
    226
    227    /** LNEG instruction. */
    228    public static final ArithmeticInstruction LNEG = new LNEG();
    229
    230    /** FNEG instruction. */
    231    public static final ArithmeticInstruction FNEG = new FNEG();
    232
    233    /** DNEG instruction. */
    234    public static final ArithmeticInstruction DNEG = new DNEG();
    235
    236    /** ISHL instruction. */
    237    public static final ArithmeticInstruction ISHL = new ISHL();
    238
    239    /** LSHL instruction. */
    240    public static final ArithmeticInstruction LSHL = new LSHL();
    241
    242    /** ISHR instruction. */
    243    public static final ArithmeticInstruction ISHR = new ISHR();
    244
    245    /** LSHR instruction. */
    246    public static final ArithmeticInstruction LSHR = new LSHR();
    247
    248    /** IUSHR instruction. */
    249    public static final ArithmeticInstruction IUSHR = new IUSHR();
    250
    251    /** LUSHR instruction. */
    252    public static final ArithmeticInstruction LUSHR = new LUSHR();
    253
    254    /** IAND instruction. */
    255    public static final ArithmeticInstruction IAND = new IAND();
    256
    257    /** LAND instruction. */
    258    public static final ArithmeticInstruction LAND = new LAND();
    259
    260    /** IOR instruction. */
    261    public static final ArithmeticInstruction IOR = new IOR();
    262
    263    /** LOR instruction. */
    264    public static final ArithmeticInstruction LOR = new LOR();
    265
    266    /** IXOR instruction. */
    267    public static final ArithmeticInstruction IXOR = new IXOR();
    268
    269    /** LXOR instruction. */
    270    public static final ArithmeticInstruction LXOR = new LXOR();
    271
    272    /** I2L instruction. */
    273    public static final ConversionInstruction I2L = new I2L();
    274
    275    /** I2F instruction. */
    276    public static final ConversionInstruction I2F = new I2F();
    277
    278    /** I2D instruction. */
    279    public static final ConversionInstruction I2D = new I2D();
    280
    281    /** L2I instruction. */
    282    public static final ConversionInstruction L2I = new L2I();
    283
    284    /** L2F instruction. */
    285    public static final ConversionInstruction L2F = new L2F();
    286
    287    /** L2D instruction. */
    288    public static final ConversionInstruction L2D = new L2D();
    289
    290    /** F2I instruction. */
    291    public static final ConversionInstruction F2I = new F2I();
    292
    293    /** F2L instruction. */
    294    public static final ConversionInstruction F2L = new F2L();
    295
    296    /** F2D instruction. */
    297    public static final ConversionInstruction F2D = new F2D();
    298
    299    /** D2I instruction. */
    300    public static final ConversionInstruction D2I = new D2I();
    301
    302    /** D2L instruction. */
    303    public static final ConversionInstruction D2L = new D2L();
    304
    305    /** D2F instruction. */
    306    public static final ConversionInstruction D2F = new D2F();
    307
    308    /** I2B instruction. */
    309    public static final ConversionInstruction I2B = new I2B();
    310
    311    /** I2C instruction. */
    312    public static final ConversionInstruction I2C = new I2C();
    313
    314    /** I2S instruction. */
    315    public static final ConversionInstruction I2S = new I2S();
    316
    317    /** LCMP instruction. */
    318    public static final Instruction LCMP = new LCMP();
    319
    320    /** FCMPL instruction. */
    321    public static final Instruction FCMPL = new FCMPL();
    322
    323    /** FCMPG instruction. */
    324    public static final Instruction FCMPG = new FCMPG();
    325
    326    /** DCMPL instruction. */
    327    public static final Instruction DCMPL = new DCMPL();
    328
    329    /** DCMPG instruction. */
    330    public static final Instruction DCMPG = new DCMPG();
    331
    332    /** IRETURN instruction. */
    333    public static final ReturnInstruction IRETURN = new IRETURN();
    334
    335    /** LRETURN instruction. */
    336    public static final ReturnInstruction LRETURN = new LRETURN();
    337
    338    /** FRETURN instruction. */
    339    public static final ReturnInstruction FRETURN = new FRETURN();
    340
    341    /** DRETURN instruction. */
    342    public static final ReturnInstruction DRETURN = new DRETURN();
    343
    344    /** ARETURN instruction. */
    345    public static final ReturnInstruction ARETURN = new ARETURN();
    346
    347    /** RETURN instruction. */
    348    public static final ReturnInstruction RETURN = new RETURN();
    349
    350    /** ARRAYLENGTH instruction. */
    351    public static final Instruction ARRAYLENGTH = new ARRAYLENGTH();
    352
    353    /** ATHROW instruction. */
    354    public static final Instruction ATHROW = new ATHROW();
    355
    356    /** MONITORENTER instruction. */
    357    public static final Instruction MONITORENTER = new MONITORENTER();
    358
    359    /** MONITOREXIT instruction. */
    360    public static final Instruction MONITOREXIT = new MONITOREXIT();
    361
    362    /**
    363     * You can use these constants in multiple places safely, if you can guarantee that you will never alter their internal values, for example call setIndex().
    364     * THIS instruction (ALOAD_0)
    365     */
    366    public static final LocalVariableInstruction THIS = new ALOAD(0);
    367
    368    /** ALOAD_0 instruction (same as THIS). */
    369    public static final LocalVariableInstruction ALOAD_0 = THIS;
    370
    371    /** ALOAD_1 instruction. */
    372    public static final LocalVariableInstruction ALOAD_1 = new ALOAD(1);
    373
    374    /** ALOAD_2 instruction. */
    375    public static final LocalVariableInstruction ALOAD_2 = new ALOAD(2);
    376
    377    /** ILOAD_0 instruction. */
    378    public static final LocalVariableInstruction ILOAD_0 = new ILOAD(0);
    379
    380    /** ILOAD_1 instruction. */
    381    public static final LocalVariableInstruction ILOAD_1 = new ILOAD(1);
    382
    383    /** ILOAD_2 instruction. */
    384    public static final LocalVariableInstruction ILOAD_2 = new ILOAD(2);
    385
    386    /** ASTORE_0 instruction. */
    387    public static final LocalVariableInstruction ASTORE_0 = new ASTORE(0);
    388
    389    /** ASTORE_1 instruction. */
    390    public static final LocalVariableInstruction ASTORE_1 = new ASTORE(1);
    391
    392    /** ASTORE_2 instruction. */
    393    public static final LocalVariableInstruction ASTORE_2 = new ASTORE(2);
    394
    395    /** ISTORE_0 instruction. */
    396    public static final LocalVariableInstruction ISTORE_0 = new ISTORE(0);
    397
    398    /** ISTORE_1 instruction. */
    399    public static final LocalVariableInstruction ISTORE_1 = new ISTORE(1);
    400
    401    /** ISTORE_2 instruction. */
    402    public static final LocalVariableInstruction ISTORE_2 = new ISTORE(2);
    403
    404    /**
    405     * Gets object via its opcode, for immutable instructions like branch instructions entries are set to null.
    406     */
    407    static final Instruction[] INSTRUCTIONS = new Instruction[256];
    408
    409    static {
    410        INSTRUCTIONS[Const.NOP] = NOP;
    411        INSTRUCTIONS[Const.ACONST_NULL] = ACONST_NULL;
    412        INSTRUCTIONS[Const.ICONST_M1] = ICONST_M1;
    413        INSTRUCTIONS[Const.ICONST_0] = ICONST_0;
    414        INSTRUCTIONS[Const.ICONST_1] = ICONST_1;
    415        INSTRUCTIONS[Const.ICONST_2] = ICONST_2;
    416        INSTRUCTIONS[Const.ICONST_3] = ICONST_3;
    417        INSTRUCTIONS[Const.ICONST_4] = ICONST_4;
    418        INSTRUCTIONS[Const.ICONST_5] = ICONST_5;
    419        INSTRUCTIONS[Const.LCONST_0] = LCONST_0;
    420        INSTRUCTIONS[Const.LCONST_1] = LCONST_1;
    421        INSTRUCTIONS[Const.FCONST_0] = FCONST_0;
    422        INSTRUCTIONS[Const.FCONST_1] = FCONST_1;
    423        INSTRUCTIONS[Const.FCONST_2] = FCONST_2;
    424        INSTRUCTIONS[Const.DCONST_0] = DCONST_0;
    425        INSTRUCTIONS[Const.DCONST_1] = DCONST_1;
    426        INSTRUCTIONS[Const.IALOAD] = IALOAD;
    427        INSTRUCTIONS[Const.LALOAD] = LALOAD;
    428        INSTRUCTIONS[Const.FALOAD] = FALOAD;
    429        INSTRUCTIONS[Const.DALOAD] = DALOAD;
    430        INSTRUCTIONS[Const.AALOAD] = AALOAD;
    431        INSTRUCTIONS[Const.BALOAD] = BALOAD;
    432        INSTRUCTIONS[Const.CALOAD] = CALOAD;
    433        INSTRUCTIONS[Const.SALOAD] = SALOAD;
    434        INSTRUCTIONS[Const.IASTORE] = IASTORE;
    435        INSTRUCTIONS[Const.LASTORE] = LASTORE;
    436        INSTRUCTIONS[Const.FASTORE] = FASTORE;
    437        INSTRUCTIONS[Const.DASTORE] = DASTORE;
    438        INSTRUCTIONS[Const.AASTORE] = AASTORE;
    439        INSTRUCTIONS[Const.BASTORE] = BASTORE;
    440        INSTRUCTIONS[Const.CASTORE] = CASTORE;
    441        INSTRUCTIONS[Const.SASTORE] = SASTORE;
    442        INSTRUCTIONS[Const.POP] = POP;
    443        INSTRUCTIONS[Const.POP2] = POP2;
    444        INSTRUCTIONS[Const.DUP] = DUP;
    445        INSTRUCTIONS[Const.DUP_X1] = DUP_X1;
    446        INSTRUCTIONS[Const.DUP_X2] = DUP_X2;
    447        INSTRUCTIONS[Const.DUP2] = DUP2;
    448        INSTRUCTIONS[Const.DUP2_X1] = DUP2_X1;
    449        INSTRUCTIONS[Const.DUP2_X2] = DUP2_X2;
    450        INSTRUCTIONS[Const.SWAP] = SWAP;
    451        INSTRUCTIONS[Const.IADD] = IADD;
    452        INSTRUCTIONS[Const.LADD] = LADD;
    453        INSTRUCTIONS[Const.FADD] = FADD;
    454        INSTRUCTIONS[Const.DADD] = DADD;
    455        INSTRUCTIONS[Const.ISUB] = ISUB;
    456        INSTRUCTIONS[Const.LSUB] = LSUB;
    457        INSTRUCTIONS[Const.FSUB] = FSUB;
    458        INSTRUCTIONS[Const.DSUB] = DSUB;
    459        INSTRUCTIONS[Const.IMUL] = IMUL;
    460        INSTRUCTIONS[Const.LMUL] = LMUL;
    461        INSTRUCTIONS[Const.FMUL] = FMUL;
    462        INSTRUCTIONS[Const.DMUL] = DMUL;
    463        INSTRUCTIONS[Const.IDIV] = IDIV;
    464        INSTRUCTIONS[Const.LDIV] = LDIV;
    465        INSTRUCTIONS[Const.FDIV] = FDIV;
    466        INSTRUCTIONS[Const.DDIV] = DDIV;
    467        INSTRUCTIONS[Const.IREM] = IREM;
    468        INSTRUCTIONS[Const.LREM] = LREM;
    469        INSTRUCTIONS[Const.FREM] = FREM;
    470        INSTRUCTIONS[Const.DREM] = DREM;
    471        INSTRUCTIONS[Const.INEG] = INEG;
    472        INSTRUCTIONS[Const.LNEG] = LNEG;
    473        INSTRUCTIONS[Const.FNEG] = FNEG;
    474        INSTRUCTIONS[Const.DNEG] = DNEG;
    475        INSTRUCTIONS[Const.ISHL] = ISHL;
    476        INSTRUCTIONS[Const.LSHL] = LSHL;
    477        INSTRUCTIONS[Const.ISHR] = ISHR;
    478        INSTRUCTIONS[Const.LSHR] = LSHR;
    479        INSTRUCTIONS[Const.IUSHR] = IUSHR;
    480        INSTRUCTIONS[Const.LUSHR] = LUSHR;
    481        INSTRUCTIONS[Const.IAND] = IAND;
    482        INSTRUCTIONS[Const.LAND] = LAND;
    483        INSTRUCTIONS[Const.IOR] = IOR;
    484        INSTRUCTIONS[Const.LOR] = LOR;
    485        INSTRUCTIONS[Const.IXOR] = IXOR;
    486        INSTRUCTIONS[Const.LXOR] = LXOR;
    487        INSTRUCTIONS[Const.I2L] = I2L;
    488        INSTRUCTIONS[Const.I2F] = I2F;
    489        INSTRUCTIONS[Const.I2D] = I2D;
    490        INSTRUCTIONS[Const.L2I] = L2I;
    491        INSTRUCTIONS[Const.L2F] = L2F;
    492        INSTRUCTIONS[Const.L2D] = L2D;
    493        INSTRUCTIONS[Const.F2I] = F2I;
    494        INSTRUCTIONS[Const.F2L] = F2L;
    495        INSTRUCTIONS[Const.F2D] = F2D;
    496        INSTRUCTIONS[Const.D2I] = D2I;
    497        INSTRUCTIONS[Const.D2L] = D2L;
    498        INSTRUCTIONS[Const.D2F] = D2F;
    499        INSTRUCTIONS[Const.I2B] = I2B;
    500        INSTRUCTIONS[Const.I2C] = I2C;
    501        INSTRUCTIONS[Const.I2S] = I2S;
    502        INSTRUCTIONS[Const.LCMP] = LCMP;
    503        INSTRUCTIONS[Const.FCMPL] = FCMPL;
    504        INSTRUCTIONS[Const.FCMPG] = FCMPG;
    505        INSTRUCTIONS[Const.DCMPL] = DCMPL;
    506        INSTRUCTIONS[Const.DCMPG] = DCMPG;
    507        INSTRUCTIONS[Const.IRETURN] = IRETURN;
    508        INSTRUCTIONS[Const.LRETURN] = LRETURN;
    509        INSTRUCTIONS[Const.FRETURN] = FRETURN;
    510        INSTRUCTIONS[Const.DRETURN] = DRETURN;
    511        INSTRUCTIONS[Const.ARETURN] = ARETURN;
    512        INSTRUCTIONS[Const.RETURN] = RETURN;
    513        INSTRUCTIONS[Const.ARRAYLENGTH] = ARRAYLENGTH;
    514        INSTRUCTIONS[Const.ATHROW] = ATHROW;
    515        INSTRUCTIONS[Const.MONITORENTER] = MONITORENTER;
    516        INSTRUCTIONS[Const.MONITOREXIT] = MONITOREXIT;
    517    }
    518
    519    /**
    520     * Gets the Instruction.
    521     *
    522     * @param index the index, for example {@link Const#RETURN}.
    523     * @return the entry from the private INSTRUCTIONS table.
    524     */
    525    public static Instruction getInstruction(final int index) {
    526        return INSTRUCTIONS[index];
    527    }
    528
    529    private InstructionConst() {
    530    } // non-instantiable
    531}