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}