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      1 /*
      2  * ProGuard -- shrinking, optimization, obfuscation, and preverification
      3  *             of Java bytecode.
      4  *
      5  * Copyright (c) 2002-2009 Eric Lafortune (eric (at) graphics.cornell.edu)
      6  *
      7  * This program is free software; you can redistribute it and/or modify it
      8  * under the terms of the GNU General Public License as published by the Free
      9  * Software Foundation; either version 2 of the License, or (at your option)
     10  * any later version.
     11  *
     12  * This program is distributed in the hope that it will be useful, but WITHOUT
     13  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
     14  * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
     15  * more details.
     16  *
     17  * You should have received a copy of the GNU General Public License along
     18  * with this program; if not, write to the Free Software Foundation, Inc.,
     19  * 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
     20  */
     21 package proguard.classfile.instruction;
     22 
     23 /**
     24  * This class provides methods to create and reuse Instruction objects.
     25  *
     26  * @author Eric Lafortune
     27  */
     28 public class InstructionFactory
     29 {
     30     /**
     31      * Creates a new Instruction from the data in the byte array, starting
     32      * at the given index.
     33      */
     34     public static Instruction create(byte[] code, int offset)
     35     {
     36         Instruction instruction;
     37 
     38         int  index  = offset;
     39         byte opcode = code[index++];
     40 
     41         boolean wide = false;
     42         if (opcode == InstructionConstants.OP_WIDE)
     43         {
     44             opcode = code[index++];
     45             wide   = true;
     46         }
     47 
     48         switch (opcode)
     49         {
     50             // Simple instructions.
     51             case InstructionConstants.OP_NOP:
     52             case InstructionConstants.OP_ACONST_NULL:
     53             case InstructionConstants.OP_ICONST_M1:
     54             case InstructionConstants.OP_ICONST_0:
     55             case InstructionConstants.OP_ICONST_1:
     56             case InstructionConstants.OP_ICONST_2:
     57             case InstructionConstants.OP_ICONST_3:
     58             case InstructionConstants.OP_ICONST_4:
     59             case InstructionConstants.OP_ICONST_5:
     60             case InstructionConstants.OP_LCONST_0:
     61             case InstructionConstants.OP_LCONST_1:
     62             case InstructionConstants.OP_FCONST_0:
     63             case InstructionConstants.OP_FCONST_1:
     64             case InstructionConstants.OP_FCONST_2:
     65             case InstructionConstants.OP_DCONST_0:
     66             case InstructionConstants.OP_DCONST_1:
     67 
     68             case InstructionConstants.OP_BIPUSH:
     69             case InstructionConstants.OP_SIPUSH:
     70 
     71             case InstructionConstants.OP_IALOAD:
     72             case InstructionConstants.OP_LALOAD:
     73             case InstructionConstants.OP_FALOAD:
     74             case InstructionConstants.OP_DALOAD:
     75             case InstructionConstants.OP_AALOAD:
     76             case InstructionConstants.OP_BALOAD:
     77             case InstructionConstants.OP_CALOAD:
     78             case InstructionConstants.OP_SALOAD:
     79 
     80             case InstructionConstants.OP_IASTORE:
     81             case InstructionConstants.OP_LASTORE:
     82             case InstructionConstants.OP_FASTORE:
     83             case InstructionConstants.OP_DASTORE:
     84             case InstructionConstants.OP_AASTORE:
     85             case InstructionConstants.OP_BASTORE:
     86             case InstructionConstants.OP_CASTORE:
     87             case InstructionConstants.OP_SASTORE:
     88             case InstructionConstants.OP_POP:
     89             case InstructionConstants.OP_POP2:
     90             case InstructionConstants.OP_DUP:
     91             case InstructionConstants.OP_DUP_X1:
     92             case InstructionConstants.OP_DUP_X2:
     93             case InstructionConstants.OP_DUP2:
     94             case InstructionConstants.OP_DUP2_X1:
     95             case InstructionConstants.OP_DUP2_X2:
     96             case InstructionConstants.OP_SWAP:
     97             case InstructionConstants.OP_IADD:
     98             case InstructionConstants.OP_LADD:
     99             case InstructionConstants.OP_FADD:
    100             case InstructionConstants.OP_DADD:
    101             case InstructionConstants.OP_ISUB:
    102             case InstructionConstants.OP_LSUB:
    103             case InstructionConstants.OP_FSUB:
    104             case InstructionConstants.OP_DSUB:
    105             case InstructionConstants.OP_IMUL:
    106             case InstructionConstants.OP_LMUL:
    107             case InstructionConstants.OP_FMUL:
    108             case InstructionConstants.OP_DMUL:
    109             case InstructionConstants.OP_IDIV:
    110             case InstructionConstants.OP_LDIV:
    111             case InstructionConstants.OP_FDIV:
    112             case InstructionConstants.OP_DDIV:
    113             case InstructionConstants.OP_IREM:
    114             case InstructionConstants.OP_LREM:
    115             case InstructionConstants.OP_FREM:
    116             case InstructionConstants.OP_DREM:
    117             case InstructionConstants.OP_INEG:
    118             case InstructionConstants.OP_LNEG:
    119             case InstructionConstants.OP_FNEG:
    120             case InstructionConstants.OP_DNEG:
    121             case InstructionConstants.OP_ISHL:
    122             case InstructionConstants.OP_LSHL:
    123             case InstructionConstants.OP_ISHR:
    124             case InstructionConstants.OP_LSHR:
    125             case InstructionConstants.OP_IUSHR:
    126             case InstructionConstants.OP_LUSHR:
    127             case InstructionConstants.OP_IAND:
    128             case InstructionConstants.OP_LAND:
    129             case InstructionConstants.OP_IOR:
    130             case InstructionConstants.OP_LOR:
    131             case InstructionConstants.OP_IXOR:
    132             case InstructionConstants.OP_LXOR:
    133 
    134             case InstructionConstants.OP_I2L:
    135             case InstructionConstants.OP_I2F:
    136             case InstructionConstants.OP_I2D:
    137             case InstructionConstants.OP_L2I:
    138             case InstructionConstants.OP_L2F:
    139             case InstructionConstants.OP_L2D:
    140             case InstructionConstants.OP_F2I:
    141             case InstructionConstants.OP_F2L:
    142             case InstructionConstants.OP_F2D:
    143             case InstructionConstants.OP_D2I:
    144             case InstructionConstants.OP_D2L:
    145             case InstructionConstants.OP_D2F:
    146             case InstructionConstants.OP_I2B:
    147             case InstructionConstants.OP_I2C:
    148             case InstructionConstants.OP_I2S:
    149             case InstructionConstants.OP_LCMP:
    150             case InstructionConstants.OP_FCMPL:
    151             case InstructionConstants.OP_FCMPG:
    152             case InstructionConstants.OP_DCMPL:
    153             case InstructionConstants.OP_DCMPG:
    154 
    155             case InstructionConstants.OP_IRETURN:
    156             case InstructionConstants.OP_LRETURN:
    157             case InstructionConstants.OP_FRETURN:
    158             case InstructionConstants.OP_DRETURN:
    159             case InstructionConstants.OP_ARETURN:
    160             case InstructionConstants.OP_RETURN:
    161 
    162             case InstructionConstants.OP_NEWARRAY:
    163             case InstructionConstants.OP_ARRAYLENGTH:
    164             case InstructionConstants.OP_ATHROW:
    165 
    166             case InstructionConstants.OP_MONITORENTER:
    167             case InstructionConstants.OP_MONITOREXIT:
    168                 instruction = new SimpleInstruction();
    169                 break;
    170 
    171             // Instructions with a contant pool index.
    172             case InstructionConstants.OP_LDC:
    173             case InstructionConstants.OP_LDC_W:
    174             case InstructionConstants.OP_LDC2_W:
    175 
    176             case InstructionConstants.OP_GETSTATIC:
    177             case InstructionConstants.OP_PUTSTATIC:
    178             case InstructionConstants.OP_GETFIELD:
    179             case InstructionConstants.OP_PUTFIELD:
    180 
    181             case InstructionConstants.OP_INVOKEVIRTUAL:
    182             case InstructionConstants.OP_INVOKESPECIAL:
    183             case InstructionConstants.OP_INVOKESTATIC:
    184             case InstructionConstants.OP_INVOKEINTERFACE:
    185 
    186             case InstructionConstants.OP_NEW:
    187             case InstructionConstants.OP_ANEWARRAY:
    188             case InstructionConstants.OP_CHECKCAST:
    189             case InstructionConstants.OP_INSTANCEOF:
    190             case InstructionConstants.OP_MULTIANEWARRAY:
    191                 instruction = new ConstantInstruction();
    192                 break;
    193 
    194             // Instructions with a local variable index.
    195             case InstructionConstants.OP_ILOAD:
    196             case InstructionConstants.OP_LLOAD:
    197             case InstructionConstants.OP_FLOAD:
    198             case InstructionConstants.OP_DLOAD:
    199             case InstructionConstants.OP_ALOAD:
    200             case InstructionConstants.OP_ILOAD_0:
    201             case InstructionConstants.OP_ILOAD_1:
    202             case InstructionConstants.OP_ILOAD_2:
    203             case InstructionConstants.OP_ILOAD_3:
    204             case InstructionConstants.OP_LLOAD_0:
    205             case InstructionConstants.OP_LLOAD_1:
    206             case InstructionConstants.OP_LLOAD_2:
    207             case InstructionConstants.OP_LLOAD_3:
    208             case InstructionConstants.OP_FLOAD_0:
    209             case InstructionConstants.OP_FLOAD_1:
    210             case InstructionConstants.OP_FLOAD_2:
    211             case InstructionConstants.OP_FLOAD_3:
    212             case InstructionConstants.OP_DLOAD_0:
    213             case InstructionConstants.OP_DLOAD_1:
    214             case InstructionConstants.OP_DLOAD_2:
    215             case InstructionConstants.OP_DLOAD_3:
    216             case InstructionConstants.OP_ALOAD_0:
    217             case InstructionConstants.OP_ALOAD_1:
    218             case InstructionConstants.OP_ALOAD_2:
    219             case InstructionConstants.OP_ALOAD_3:
    220 
    221             case InstructionConstants.OP_ISTORE:
    222             case InstructionConstants.OP_LSTORE:
    223             case InstructionConstants.OP_FSTORE:
    224             case InstructionConstants.OP_DSTORE:
    225             case InstructionConstants.OP_ASTORE:
    226             case InstructionConstants.OP_ISTORE_0:
    227             case InstructionConstants.OP_ISTORE_1:
    228             case InstructionConstants.OP_ISTORE_2:
    229             case InstructionConstants.OP_ISTORE_3:
    230             case InstructionConstants.OP_LSTORE_0:
    231             case InstructionConstants.OP_LSTORE_1:
    232             case InstructionConstants.OP_LSTORE_2:
    233             case InstructionConstants.OP_LSTORE_3:
    234             case InstructionConstants.OP_FSTORE_0:
    235             case InstructionConstants.OP_FSTORE_1:
    236             case InstructionConstants.OP_FSTORE_2:
    237             case InstructionConstants.OP_FSTORE_3:
    238             case InstructionConstants.OP_DSTORE_0:
    239             case InstructionConstants.OP_DSTORE_1:
    240             case InstructionConstants.OP_DSTORE_2:
    241             case InstructionConstants.OP_DSTORE_3:
    242             case InstructionConstants.OP_ASTORE_0:
    243             case InstructionConstants.OP_ASTORE_1:
    244             case InstructionConstants.OP_ASTORE_2:
    245             case InstructionConstants.OP_ASTORE_3:
    246 
    247             case InstructionConstants.OP_IINC:
    248 
    249             case InstructionConstants.OP_RET:
    250                 instruction = new VariableInstruction(wide);
    251                 break;
    252 
    253             // Instructions with a branch offset operand.
    254             case InstructionConstants.OP_IFEQ:
    255             case InstructionConstants.OP_IFNE:
    256             case InstructionConstants.OP_IFLT:
    257             case InstructionConstants.OP_IFGE:
    258             case InstructionConstants.OP_IFGT:
    259             case InstructionConstants.OP_IFLE:
    260             case InstructionConstants.OP_IFICMPEQ:
    261             case InstructionConstants.OP_IFICMPNE:
    262             case InstructionConstants.OP_IFICMPLT:
    263             case InstructionConstants.OP_IFICMPGE:
    264             case InstructionConstants.OP_IFICMPGT:
    265             case InstructionConstants.OP_IFICMPLE:
    266             case InstructionConstants.OP_IFACMPEQ:
    267             case InstructionConstants.OP_IFACMPNE:
    268             case InstructionConstants.OP_GOTO:
    269             case InstructionConstants.OP_JSR:
    270 
    271             case InstructionConstants.OP_IFNULL:
    272             case InstructionConstants.OP_IFNONNULL:
    273 
    274             case InstructionConstants.OP_GOTO_W:
    275             case InstructionConstants.OP_JSR_W:
    276                 instruction = new BranchInstruction();
    277                 break;
    278 
    279             //  The tableswitch instruction.
    280             case InstructionConstants.OP_TABLESWITCH:
    281                 instruction = new TableSwitchInstruction();
    282                 break;
    283 
    284             //  The lookupswitch instruction.
    285             case InstructionConstants.OP_LOOKUPSWITCH:
    286                 instruction = new LookUpSwitchInstruction();
    287                 break;
    288 
    289             default:
    290                 throw new IllegalArgumentException("Unknown instruction opcode ["+opcode+"] at offset "+offset);
    291         }
    292 
    293         instruction.opcode = opcode;
    294 
    295         instruction.readInfo(code, index);
    296 
    297         return instruction;
    298     }
    299 }
    300