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