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BytecodeArray.javaAPI DocAndroid 5.1 API53451Thu Mar 12 22:18:30 GMT 2015com.android.dx.cf.code

BytecodeArray

public final class BytecodeArray extends Object
Bytecode array, which is part of a standard {@code Code} attribute.

Fields Summary
public static final Visitor
EMPTY_VISITOR
convenient no-op implementation of {@link Visitor}
private final com.android.dx.util.ByteArray
bytes
{@code non-null;} underlying bytes
private final com.android.dx.rop.cst.ConstantPool
pool
{@code non-null;} constant pool to use when resolving constant pool indices
Constructors Summary
public BytecodeArray(com.android.dx.util.ByteArray bytes, com.android.dx.rop.cst.ConstantPool pool)
Constructs an instance.

param
bytes {@code non-null;} underlying bytes
param
pool {@code non-null;} constant pool to use when resolving constant pool indices


                               
         
        if (bytes == null) {
            throw new NullPointerException("bytes == null");
        }

        if (pool == null) {
            throw new NullPointerException("pool == null");
        }

        this.bytes = bytes;
        this.pool = pool;
Methods Summary
public intbyteLength()
Gets the total length of this structure in bytes, when included in a {@code Code} attribute. The returned value includes the array size plus four bytes for {@code code_length}.

return
{@code >= 4;} the total length, in bytes

        return 4 + bytes.size();
public voidforEach(com.android.dx.cf.code.BytecodeArray$Visitor visitor)
Parses each instruction in the array, in order.

param
visitor {@code null-ok;} visitor to call back to for each instruction

        int sz = bytes.size();
        int at = 0;

        while (at < sz) {
            /*
             * Don't record the previous offset here, so that we get to see the
             * raw code that initializes the array
             */
            at += parseInstruction(at, visitor);
        }
public com.android.dx.util.ByteArraygetBytes()
Gets the underlying byte array.

return
{@code non-null;} the byte array

        return bytes;
public int[]getInstructionOffsets()
Finds the offset to each instruction in the bytecode array. The result is a bit set with the offset of each opcode-per-se flipped on.

see
Bits
return
{@code non-null;} appropriately constructed bit set

        int sz = bytes.size();
        int[] result = Bits.makeBitSet(sz);
        int at = 0;

        while (at < sz) {
            Bits.set(result, at, true);
            int length = parseInstruction(at, null);
            at += length;
        }

        return result;
public intparseInstruction(int offset, com.android.dx.cf.code.BytecodeArray$Visitor visitor)
Parses the instruction at the indicated offset. Indicate the result by calling the visitor if supplied and by returning the number of bytes consumed by the instruction.

In order to simplify further processing, the opcodes passed to the visitor are canonicalized, altering the opcode to a more universal one and making formerly implicit arguments explicit. In particular:

  • The opcodes to push literal constants of primitive types all become {@code ldc}. E.g., {@code fconst_0}, {@code sipush}, and {@code lconst_0} qualify for this treatment.
  • {@code aconst_null} becomes {@code ldc} of a "known null."
  • Shorthand local variable accessors become the corresponding longhand. E.g. {@code aload_2} becomes {@code aload}.
  • {@code goto_w} and {@code jsr_w} become {@code goto} and {@code jsr} (respectively).
  • {@code ldc_w} becomes {@code ldc}.
  • {@code tableswitch} becomes {@code lookupswitch}.
  • Arithmetic, array, and value-returning ops are collapsed to the {@code int} variant opcode, with the {@code type} argument set to indicate the actual type. E.g., {@code fadd} becomes {@code iadd}, but {@code type} is passed as {@code Type.FLOAT} in that case. Similarly, {@code areturn} becomes {@code ireturn}. (However, {@code return} remains unchanged.
  • Local variable access ops are collapsed to the {@code int} variant opcode, with the {@code type} argument set to indicate the actual type. E.g., {@code aload} becomes {@code iload}, but {@code type} is passed as {@code Type.OBJECT} in that case.
  • Numeric conversion ops ({@code i2l}, etc.) are left alone to avoid too much confustion, but their {@code type} is the pushed type. E.g., {@code i2b} gets type {@code Type.INT}, and {@code f2d} gets type {@code Type.DOUBLE}. Other unaltered opcodes also get their pushed type. E.g., {@code arraylength} gets type {@code Type.INT}.

param
offset {@code >= 0, < bytes.size();} offset to the start of the instruction
param
visitor {@code null-ok;} visitor to call back to
return
the length of the instruction, in bytes

        if (visitor == null) {
            visitor = EMPTY_VISITOR;
        }

        try {
            int opcode = bytes.getUnsignedByte(offset);
            int info = ByteOps.opInfo(opcode);
            int fmt = info & ByteOps.FMT_MASK;

            switch (opcode) {
                case ByteOps.NOP: {
                    visitor.visitNoArgs(opcode, offset, 1, Type.VOID);
                    return 1;
                }
                case ByteOps.ACONST_NULL: {
                    visitor.visitConstant(ByteOps.LDC, offset, 1,
                                          CstKnownNull.THE_ONE, 0);
                    return 1;
                }
                case ByteOps.ICONST_M1: {
                    visitor.visitConstant(ByteOps.LDC, offset, 1,
                                          CstInteger.VALUE_M1, -1);
                    return 1;
                }
                case ByteOps.ICONST_0: {
                    visitor.visitConstant(ByteOps.LDC, offset, 1,
                                          CstInteger.VALUE_0, 0);
                    return 1;
                }
                case ByteOps.ICONST_1: {
                    visitor.visitConstant(ByteOps.LDC, offset, 1,
                                          CstInteger.VALUE_1, 1);
                    return 1;
                }
                case ByteOps.ICONST_2: {
                    visitor.visitConstant(ByteOps.LDC, offset, 1,
                                          CstInteger.VALUE_2, 2);
                    return 1;
                }
                case ByteOps.ICONST_3: {
                    visitor.visitConstant(ByteOps.LDC, offset, 1,
                                          CstInteger.VALUE_3, 3);
                    return 1;
                }
                case ByteOps.ICONST_4: {
                    visitor.visitConstant(ByteOps.LDC, offset, 1,
                                          CstInteger.VALUE_4, 4);
                    return 1;
                }
                case ByteOps.ICONST_5:  {
                    visitor.visitConstant(ByteOps.LDC, offset, 1,
                                          CstInteger.VALUE_5, 5);
                    return 1;
                }
                case ByteOps.LCONST_0: {
                    visitor.visitConstant(ByteOps.LDC, offset, 1,
                                          CstLong.VALUE_0, 0);
                    return 1;
                }
                case ByteOps.LCONST_1: {
                    visitor.visitConstant(ByteOps.LDC, offset, 1,
                                          CstLong.VALUE_1, 0);
                    return 1;
                }
                case ByteOps.FCONST_0: {
                    visitor.visitConstant(ByteOps.LDC, offset, 1,
                                          CstFloat.VALUE_0, 0);
                    return 1;
                }
                case ByteOps.FCONST_1: {
                    visitor.visitConstant(ByteOps.LDC, offset, 1,
                                          CstFloat.VALUE_1, 0);
                    return 1;
                }
                case ByteOps.FCONST_2:  {
                    visitor.visitConstant(ByteOps.LDC, offset, 1,
                                          CstFloat.VALUE_2, 0);
                    return 1;
                }
                case ByteOps.DCONST_0: {
                    visitor.visitConstant(ByteOps.LDC, offset, 1,
                                          CstDouble.VALUE_0, 0);
                    return 1;
                }
                case ByteOps.DCONST_1: {
                    visitor.visitConstant(ByteOps.LDC, offset, 1,
                                          CstDouble.VALUE_1, 0);
                    return 1;
                }
                case ByteOps.BIPUSH: {
                    int value = bytes.getByte(offset + 1);
                    visitor.visitConstant(ByteOps.LDC, offset, 2,
                                          CstInteger.make(value), value);
                    return 2;
                }
                case ByteOps.SIPUSH: {
                    int value = bytes.getShort(offset + 1);
                    visitor.visitConstant(ByteOps.LDC, offset, 3,
                                          CstInteger.make(value), value);
                    return 3;
                }
                case ByteOps.LDC: {
                    int idx = bytes.getUnsignedByte(offset + 1);
                    Constant cst = pool.get(idx);
                    int value = (cst instanceof CstInteger) ?
                        ((CstInteger) cst).getValue() : 0;
                    visitor.visitConstant(ByteOps.LDC, offset, 2, cst, value);
                    return 2;
                }
                case ByteOps.LDC_W: {
                    int idx = bytes.getUnsignedShort(offset + 1);
                    Constant cst = pool.get(idx);
                    int value = (cst instanceof CstInteger) ?
                        ((CstInteger) cst).getValue() : 0;
                    visitor.visitConstant(ByteOps.LDC, offset, 3, cst, value);
                    return 3;
                }
                case ByteOps.LDC2_W: {
                    int idx = bytes.getUnsignedShort(offset + 1);
                    Constant cst = pool.get(idx);
                    visitor.visitConstant(ByteOps.LDC2_W, offset, 3, cst, 0);
                    return 3;
                }
                case ByteOps.ILOAD: {
                    int idx = bytes.getUnsignedByte(offset + 1);
                    visitor.visitLocal(ByteOps.ILOAD, offset, 2, idx,
                                       Type.INT, 0);
                    return 2;
                }
                case ByteOps.LLOAD: {
                    int idx = bytes.getUnsignedByte(offset + 1);
                    visitor.visitLocal(ByteOps.ILOAD, offset, 2, idx,
                                       Type.LONG, 0);
                    return 2;
                }
                case ByteOps.FLOAD: {
                    int idx = bytes.getUnsignedByte(offset + 1);
                    visitor.visitLocal(ByteOps.ILOAD, offset, 2, idx,
                                       Type.FLOAT, 0);
                    return 2;
                }
                case ByteOps.DLOAD: {
                    int idx = bytes.getUnsignedByte(offset + 1);
                    visitor.visitLocal(ByteOps.ILOAD, offset, 2, idx,
                                       Type.DOUBLE, 0);
                    return 2;
                }
                case ByteOps.ALOAD: {
                    int idx = bytes.getUnsignedByte(offset + 1);
                    visitor.visitLocal(ByteOps.ILOAD, offset, 2, idx,
                                       Type.OBJECT, 0);
                    return 2;
                }
                case ByteOps.ILOAD_0:
                case ByteOps.ILOAD_1:
                case ByteOps.ILOAD_2:
                case ByteOps.ILOAD_3: {
                    int idx = opcode - ByteOps.ILOAD_0;
                    visitor.visitLocal(ByteOps.ILOAD, offset, 1, idx,
                                       Type.INT, 0);
                    return 1;
                }
                case ByteOps.LLOAD_0:
                case ByteOps.LLOAD_1:
                case ByteOps.LLOAD_2:
                case ByteOps.LLOAD_3: {
                    int idx = opcode - ByteOps.LLOAD_0;
                    visitor.visitLocal(ByteOps.ILOAD, offset, 1, idx,
                                       Type.LONG, 0);
                    return 1;
                }
                case ByteOps.FLOAD_0:
                case ByteOps.FLOAD_1:
                case ByteOps.FLOAD_2:
                case ByteOps.FLOAD_3: {
                    int idx = opcode - ByteOps.FLOAD_0;
                    visitor.visitLocal(ByteOps.ILOAD, offset, 1, idx,
                                       Type.FLOAT, 0);
                    return 1;
                }
                case ByteOps.DLOAD_0:
                case ByteOps.DLOAD_1:
                case ByteOps.DLOAD_2:
                case ByteOps.DLOAD_3: {
                    int idx = opcode - ByteOps.DLOAD_0;
                    visitor.visitLocal(ByteOps.ILOAD, offset, 1, idx,
                                       Type.DOUBLE, 0);
                    return 1;
                }
                case ByteOps.ALOAD_0:
                case ByteOps.ALOAD_1:
                case ByteOps.ALOAD_2:
                case ByteOps.ALOAD_3: {
                    int idx = opcode - ByteOps.ALOAD_0;
                    visitor.visitLocal(ByteOps.ILOAD, offset, 1, idx,
                                       Type.OBJECT, 0);
                    return 1;
                }
                case ByteOps.IALOAD: {
                    visitor.visitNoArgs(ByteOps.IALOAD, offset, 1, Type.INT);
                    return 1;
                }
                case ByteOps.LALOAD: {
                    visitor.visitNoArgs(ByteOps.IALOAD, offset, 1, Type.LONG);
                    return 1;
                }
                case ByteOps.FALOAD: {
                    visitor.visitNoArgs(ByteOps.IALOAD, offset, 1,
                                        Type.FLOAT);
                    return 1;
                }
                case ByteOps.DALOAD: {
                    visitor.visitNoArgs(ByteOps.IALOAD, offset, 1,
                                        Type.DOUBLE);
                    return 1;
                }
                case ByteOps.AALOAD: {
                    visitor.visitNoArgs(ByteOps.IALOAD, offset, 1,
                                        Type.OBJECT);
                    return 1;
                }
                case ByteOps.BALOAD: {
                    /*
                     * Note: This is a load from either a byte[] or a
                     * boolean[].
                     */
                    visitor.visitNoArgs(ByteOps.IALOAD, offset, 1, Type.BYTE);
                    return 1;
                }
                case ByteOps.CALOAD: {
                    visitor.visitNoArgs(ByteOps.IALOAD, offset, 1, Type.CHAR);
                    return 1;
                }
                case ByteOps.SALOAD: {
                    visitor.visitNoArgs(ByteOps.IALOAD, offset, 1,
                                        Type.SHORT);
                    return 1;
                }
                case ByteOps.ISTORE: {
                    int idx = bytes.getUnsignedByte(offset + 1);
                    visitor.visitLocal(ByteOps.ISTORE, offset, 2, idx,
                                       Type.INT, 0);
                    return 2;
                }
                case ByteOps.LSTORE: {
                    int idx = bytes.getUnsignedByte(offset + 1);
                    visitor.visitLocal(ByteOps.ISTORE, offset, 2, idx,
                                       Type.LONG, 0);
                    return 2;
                }
                case ByteOps.FSTORE: {
                    int idx = bytes.getUnsignedByte(offset + 1);
                    visitor.visitLocal(ByteOps.ISTORE, offset, 2, idx,
                                       Type.FLOAT, 0);
                    return 2;
                }
                case ByteOps.DSTORE: {
                    int idx = bytes.getUnsignedByte(offset + 1);
                    visitor.visitLocal(ByteOps.ISTORE, offset, 2, idx,
                                       Type.DOUBLE, 0);
                    return 2;
                }
                case ByteOps.ASTORE: {
                    int idx = bytes.getUnsignedByte(offset + 1);
                    visitor.visitLocal(ByteOps.ISTORE, offset, 2, idx,
                                       Type.OBJECT, 0);
                    return 2;
                }
                case ByteOps.ISTORE_0:
                case ByteOps.ISTORE_1:
                case ByteOps.ISTORE_2:
                case ByteOps.ISTORE_3: {
                    int idx = opcode - ByteOps.ISTORE_0;
                    visitor.visitLocal(ByteOps.ISTORE, offset, 1, idx,
                                       Type.INT, 0);
                    return 1;
                }
                case ByteOps.LSTORE_0:
                case ByteOps.LSTORE_1:
                case ByteOps.LSTORE_2:
                case ByteOps.LSTORE_3: {
                    int idx = opcode - ByteOps.LSTORE_0;
                    visitor.visitLocal(ByteOps.ISTORE, offset, 1, idx,
                                       Type.LONG, 0);
                    return 1;
                }
                case ByteOps.FSTORE_0:
                case ByteOps.FSTORE_1:
                case ByteOps.FSTORE_2:
                case ByteOps.FSTORE_3: {
                    int idx = opcode - ByteOps.FSTORE_0;
                    visitor.visitLocal(ByteOps.ISTORE, offset, 1, idx,
                                       Type.FLOAT, 0);
                    return 1;
                }
                case ByteOps.DSTORE_0:
                case ByteOps.DSTORE_1:
                case ByteOps.DSTORE_2:
                case ByteOps.DSTORE_3: {
                    int idx = opcode - ByteOps.DSTORE_0;
                    visitor.visitLocal(ByteOps.ISTORE, offset, 1, idx,
                                       Type.DOUBLE, 0);
                    return 1;
                }
                case ByteOps.ASTORE_0:
                case ByteOps.ASTORE_1:
                case ByteOps.ASTORE_2:
                case ByteOps.ASTORE_3: {
                    int idx = opcode - ByteOps.ASTORE_0;
                    visitor.visitLocal(ByteOps.ISTORE, offset, 1, idx,
                                       Type.OBJECT, 0);
                    return 1;
                }
                case ByteOps.IASTORE: {
                    visitor.visitNoArgs(ByteOps.IASTORE, offset, 1, Type.INT);
                    return 1;
                }
                case ByteOps.LASTORE: {
                    visitor.visitNoArgs(ByteOps.IASTORE, offset, 1,
                                        Type.LONG);
                    return 1;
                }
                case ByteOps.FASTORE: {
                    visitor.visitNoArgs(ByteOps.IASTORE, offset, 1,
                                        Type.FLOAT);
                    return 1;
                }
                case ByteOps.DASTORE: {
                    visitor.visitNoArgs(ByteOps.IASTORE, offset, 1,
                                        Type.DOUBLE);
                    return 1;
                }
                case ByteOps.AASTORE: {
                    visitor.visitNoArgs(ByteOps.IASTORE, offset, 1,
                                        Type.OBJECT);
                    return 1;
                }
                case ByteOps.BASTORE: {
                    /*
                     * Note: This is a load from either a byte[] or a
                     * boolean[].
                     */
                    visitor.visitNoArgs(ByteOps.IASTORE, offset, 1,
                                        Type.BYTE);
                    return 1;
                }
                case ByteOps.CASTORE: {
                    visitor.visitNoArgs(ByteOps.IASTORE, offset, 1,
                                        Type.CHAR);
                    return 1;
                }
                case ByteOps.SASTORE: {
                    visitor.visitNoArgs(ByteOps.IASTORE, offset, 1,
                                        Type.SHORT);
                    return 1;
                }
                case ByteOps.POP:
                case ByteOps.POP2:
                case ByteOps.DUP:
                case ByteOps.DUP_X1:
                case ByteOps.DUP_X2:
                case ByteOps.DUP2:
                case ByteOps.DUP2_X1:
                case ByteOps.DUP2_X2:
                case ByteOps.SWAP: {
                    visitor.visitNoArgs(opcode, offset, 1, Type.VOID);
                    return 1;
                }
                case ByteOps.IADD:
                case ByteOps.ISUB:
                case ByteOps.IMUL:
                case ByteOps.IDIV:
                case ByteOps.IREM:
                case ByteOps.INEG:
                case ByteOps.ISHL:
                case ByteOps.ISHR:
                case ByteOps.IUSHR:
                case ByteOps.IAND:
                case ByteOps.IOR:
                case ByteOps.IXOR: {
                    visitor.visitNoArgs(opcode, offset, 1, Type.INT);
                    return 1;
                }
                case ByteOps.LADD:
                case ByteOps.LSUB:
                case ByteOps.LMUL:
                case ByteOps.LDIV:
                case ByteOps.LREM:
                case ByteOps.LNEG:
                case ByteOps.LSHL:
                case ByteOps.LSHR:
                case ByteOps.LUSHR:
                case ByteOps.LAND:
                case ByteOps.LOR:
                case ByteOps.LXOR: {
                    /*
                     * It's "opcode - 1" because, conveniently enough, all
                     * these long ops are one past the int variants.
                     */
                    visitor.visitNoArgs(opcode - 1, offset, 1, Type.LONG);
                    return 1;
                }
                case ByteOps.FADD:
                case ByteOps.FSUB:
                case ByteOps.FMUL:
                case ByteOps.FDIV:
                case ByteOps.FREM:
                case ByteOps.FNEG: {
                    /*
                     * It's "opcode - 2" because, conveniently enough, all
                     * these float ops are two past the int variants.
                     */
                    visitor.visitNoArgs(opcode - 2, offset, 1, Type.FLOAT);
                    return 1;
                }
                case ByteOps.DADD:
                case ByteOps.DSUB:
                case ByteOps.DMUL:
                case ByteOps.DDIV:
                case ByteOps.DREM:
                case ByteOps.DNEG: {
                    /*
                     * It's "opcode - 3" because, conveniently enough, all
                     * these double ops are three past the int variants.
                     */
                    visitor.visitNoArgs(opcode - 3, offset, 1, Type.DOUBLE);
                    return 1;
                }
                case ByteOps.IINC: {
                    int idx = bytes.getUnsignedByte(offset + 1);
                    int value = bytes.getByte(offset + 2);
                    visitor.visitLocal(opcode, offset, 3, idx,
                                       Type.INT, value);
                    return 3;
                }
                case ByteOps.I2L:
                case ByteOps.F2L:
                case ByteOps.D2L: {
                    visitor.visitNoArgs(opcode, offset, 1, Type.LONG);
                    return 1;
                }
                case ByteOps.I2F:
                case ByteOps.L2F:
                case ByteOps.D2F: {
                    visitor.visitNoArgs(opcode, offset, 1, Type.FLOAT);
                    return 1;
                }
                case ByteOps.I2D:
                case ByteOps.L2D:
                case ByteOps.F2D: {
                    visitor.visitNoArgs(opcode, offset, 1, Type.DOUBLE);
                    return 1;
                }
                case ByteOps.L2I:
                case ByteOps.F2I:
                case ByteOps.D2I:
                case ByteOps.I2B:
                case ByteOps.I2C:
                case ByteOps.I2S:
                case ByteOps.LCMP:
                case ByteOps.FCMPL:
                case ByteOps.FCMPG:
                case ByteOps.DCMPL:
                case ByteOps.DCMPG:
                case ByteOps.ARRAYLENGTH: {
                    visitor.visitNoArgs(opcode, offset, 1, Type.INT);
                    return 1;
                }
                case ByteOps.IFEQ:
                case ByteOps.IFNE:
                case ByteOps.IFLT:
                case ByteOps.IFGE:
                case ByteOps.IFGT:
                case ByteOps.IFLE:
                case ByteOps.IF_ICMPEQ:
                case ByteOps.IF_ICMPNE:
                case ByteOps.IF_ICMPLT:
                case ByteOps.IF_ICMPGE:
                case ByteOps.IF_ICMPGT:
                case ByteOps.IF_ICMPLE:
                case ByteOps.IF_ACMPEQ:
                case ByteOps.IF_ACMPNE:
                case ByteOps.GOTO:
                case ByteOps.JSR:
                case ByteOps.IFNULL:
                case ByteOps.IFNONNULL: {
                    int target = offset + bytes.getShort(offset + 1);
                    visitor.visitBranch(opcode, offset, 3, target);
                    return 3;
                }
                case ByteOps.RET: {
                    int idx = bytes.getUnsignedByte(offset + 1);
                    visitor.visitLocal(opcode, offset, 2, idx,
                                       Type.RETURN_ADDRESS, 0);
                    return 2;
                }
                case ByteOps.TABLESWITCH: {
                    return parseTableswitch(offset, visitor);
                }
                case ByteOps.LOOKUPSWITCH: {
                    return parseLookupswitch(offset, visitor);
                }
                case ByteOps.IRETURN: {
                    visitor.visitNoArgs(ByteOps.IRETURN, offset, 1, Type.INT);
                    return 1;
                }
                case ByteOps.LRETURN: {
                    visitor.visitNoArgs(ByteOps.IRETURN, offset, 1,
                                        Type.LONG);
                    return 1;
                }
                case ByteOps.FRETURN: {
                    visitor.visitNoArgs(ByteOps.IRETURN, offset, 1,
                                        Type.FLOAT);
                    return 1;
                }
                case ByteOps.DRETURN: {
                    visitor.visitNoArgs(ByteOps.IRETURN, offset, 1,
                                        Type.DOUBLE);
                    return 1;
                }
                case ByteOps.ARETURN: {
                    visitor.visitNoArgs(ByteOps.IRETURN, offset, 1,
                                        Type.OBJECT);
                    return 1;
                }
                case ByteOps.RETURN:
                case ByteOps.ATHROW:
                case ByteOps.MONITORENTER:
                case ByteOps.MONITOREXIT: {
                    visitor.visitNoArgs(opcode, offset, 1, Type.VOID);
                    return 1;
                }
                case ByteOps.GETSTATIC:
                case ByteOps.PUTSTATIC:
                case ByteOps.GETFIELD:
                case ByteOps.PUTFIELD:
                case ByteOps.INVOKEVIRTUAL:
                case ByteOps.INVOKESPECIAL:
                case ByteOps.INVOKESTATIC:
                case ByteOps.NEW:
                case ByteOps.ANEWARRAY:
                case ByteOps.CHECKCAST:
                case ByteOps.INSTANCEOF: {
                    int idx = bytes.getUnsignedShort(offset + 1);
                    Constant cst = pool.get(idx);
                    visitor.visitConstant(opcode, offset, 3, cst, 0);
                    return 3;
                }
                case ByteOps.INVOKEINTERFACE: {
                    int idx = bytes.getUnsignedShort(offset + 1);
                    int count = bytes.getUnsignedByte(offset + 3);
                    int expectZero = bytes.getUnsignedByte(offset + 4);
                    Constant cst = pool.get(idx);
                    visitor.visitConstant(opcode, offset, 5, cst,
                                          count | (expectZero << 8));
                    return 5;
                }
                case ByteOps.INVOKEDYNAMIC: {
                  throw new ParseException("invokedynamic not supported");
                }
                case ByteOps.NEWARRAY: {
                    return parseNewarray(offset, visitor);
                }
                case ByteOps.WIDE: {
                    return parseWide(offset, visitor);
                }
                case ByteOps.MULTIANEWARRAY: {
                    int idx = bytes.getUnsignedShort(offset + 1);
                    int dimensions = bytes.getUnsignedByte(offset + 3);
                    Constant cst = pool.get(idx);
                    visitor.visitConstant(opcode, offset, 4, cst, dimensions);
                    return 4;
                }
                case ByteOps.GOTO_W:
                case ByteOps.JSR_W: {
                    int target = offset + bytes.getInt(offset + 1);
                    int newop =
                        (opcode == ByteOps.GOTO_W) ? ByteOps.GOTO :
                        ByteOps.JSR;
                    visitor.visitBranch(newop, offset, 5, target);
                    return 5;
                }
                default: {
                    visitor.visitInvalid(opcode, offset, 1);
                    return 1;
                }
            }
        } catch (SimException ex) {
            ex.addContext("...at bytecode offset " + Hex.u4(offset));
            throw ex;
        } catch (RuntimeException ex) {
            SimException se = new SimException(ex);
            se.addContext("...at bytecode offset " + Hex.u4(offset));
            throw se;
        }
private intparseLookupswitch(int offset, com.android.dx.cf.code.BytecodeArray$Visitor visitor)
Helper to deal with {@code lookupswitch}.

param
offset the offset to the {@code lookupswitch} opcode itself
param
visitor {@code non-null;} visitor to use
return
instruction length, in bytes

        int at = (offset + 4) & ~3; // "at" skips the padding.

        // Collect the padding.
        int padding = 0;
        for (int i = offset + 1; i < at; i++) {
            padding = (padding << 8) | bytes.getUnsignedByte(i);
        }

        int defaultTarget = offset + bytes.getInt(at);
        int npairs = bytes.getInt(at + 4);
        at += 8;

        SwitchList cases = new SwitchList(npairs);
        for (int i = 0; i < npairs; i++) {
            int match = bytes.getInt(at);
            int target = offset + bytes.getInt(at + 4);
            at += 8;
            cases.add(match, target);
        }
        cases.setDefaultTarget(defaultTarget);
        cases.removeSuperfluousDefaults();
        cases.setImmutable();

        int length = at - offset;
        visitor.visitSwitch(ByteOps.LOOKUPSWITCH, offset, length, cases,
                            padding);

        return length;
private intparseNewarray(int offset, com.android.dx.cf.code.BytecodeArray$Visitor visitor)
Helper to deal with {@code newarray}.

param
offset the offset to the {@code newarray} opcode itself
param
visitor {@code non-null;} visitor to use
return
instruction length, in bytes

        int value = bytes.getUnsignedByte(offset + 1);
        CstType type;
        switch (value) {
            case ByteOps.NEWARRAY_BOOLEAN: {
                type = CstType.BOOLEAN_ARRAY;
                break;
            }
            case ByteOps.NEWARRAY_CHAR: {
                type = CstType.CHAR_ARRAY;
                break;
            }
            case ByteOps.NEWARRAY_DOUBLE: {
                type = CstType.DOUBLE_ARRAY;
                break;
            }
            case ByteOps.NEWARRAY_FLOAT: {
                type = CstType.FLOAT_ARRAY;
                break;
            }
            case ByteOps.NEWARRAY_BYTE: {
                type = CstType.BYTE_ARRAY;
                break;
            }
            case ByteOps.NEWARRAY_SHORT: {
                type = CstType.SHORT_ARRAY;
                break;
            }
            case ByteOps.NEWARRAY_INT: {
                type = CstType.INT_ARRAY;
                break;
            }
            case ByteOps.NEWARRAY_LONG: {
                type = CstType.LONG_ARRAY;
                break;
            }
            default: {
                throw new SimException("bad newarray code " +
                        Hex.u1(value));
            }
        }

        // Revisit the previous bytecode to find out the length of the array
        int previousOffset = visitor.getPreviousOffset();
        ConstantParserVisitor constantVisitor = new ConstantParserVisitor();
        int arrayLength = 0;

        /*
         * For visitors that don't record the previous offset, -1 will be
         * seen here
         */
        if (previousOffset >= 0) {
            parseInstruction(previousOffset, constantVisitor);
            if (constantVisitor.cst instanceof CstInteger &&
                    constantVisitor.length + previousOffset == offset) {
                arrayLength = constantVisitor.value;

            }
        }

        /*
         * Try to match the array initialization idiom. For example, if the
         * subsequent code is initializing an int array, we are expecting the
         * following pattern repeatedly:
         *  dup
         *  push index
         *  push value
         *  *astore
         *
         * where the index value will be incrimented sequentially from 0 up.
         */
        int nInit = 0;
        int curOffset = offset+2;
        int lastOffset = curOffset;
        ArrayList<Constant> initVals = new ArrayList<Constant>();

        if (arrayLength != 0) {
            while (true) {
                boolean punt = false;

                // First, check if the next bytecode is dup.
                int nextByte = bytes.getUnsignedByte(curOffset++);
                if (nextByte != ByteOps.DUP)
                    break;

                /*
                 * Next, check if the expected array index is pushed to
                 * the stack.
                 */
                parseInstruction(curOffset, constantVisitor);
                if (constantVisitor.length == 0 ||
                        !(constantVisitor.cst instanceof CstInteger) ||
                        constantVisitor.value != nInit)
                    break;

                // Next, fetch the init value and record it.
                curOffset += constantVisitor.length;

                /*
                 * Next, find out what kind of constant is pushed onto
                 * the stack.
                 */
                parseInstruction(curOffset, constantVisitor);
                if (constantVisitor.length == 0 ||
                        !(constantVisitor.cst instanceof CstLiteralBits))
                    break;

                curOffset += constantVisitor.length;
                initVals.add(constantVisitor.cst);

                nextByte = bytes.getUnsignedByte(curOffset++);
                // Now, check if the value is stored to the array properly.
                switch (value) {
                    case ByteOps.NEWARRAY_BYTE:
                    case ByteOps.NEWARRAY_BOOLEAN: {
                        if (nextByte != ByteOps.BASTORE) {
                            punt = true;
                        }
                        break;
                    }
                    case ByteOps.NEWARRAY_CHAR: {
                        if (nextByte != ByteOps.CASTORE) {
                            punt = true;
                        }
                        break;
                    }
                    case ByteOps.NEWARRAY_DOUBLE: {
                        if (nextByte != ByteOps.DASTORE) {
                            punt = true;
                        }
                        break;
                    }
                    case ByteOps.NEWARRAY_FLOAT: {
                        if (nextByte != ByteOps.FASTORE) {
                            punt = true;
                        }
                        break;
                    }
                    case ByteOps.NEWARRAY_SHORT: {
                        if (nextByte != ByteOps.SASTORE) {
                            punt = true;
                        }
                        break;
                    }
                    case ByteOps.NEWARRAY_INT: {
                        if (nextByte != ByteOps.IASTORE) {
                            punt = true;
                        }
                        break;
                    }
                    case ByteOps.NEWARRAY_LONG: {
                        if (nextByte != ByteOps.LASTORE) {
                            punt = true;
                        }
                        break;
                    }
                    default:
                        punt = true;
                        break;
                }
                if (punt) {
                    break;
                }
                lastOffset = curOffset;
                nInit++;
            }
        }

        /*
         * For singleton arrays it is still more economical to
         * generate the aput.
         */
        if (nInit < 2 || nInit != arrayLength) {
            visitor.visitNewarray(offset, 2, type, null);
            return 2;
        } else {
            visitor.visitNewarray(offset, lastOffset - offset, type, initVals);
            return lastOffset - offset;
        }
private intparseTableswitch(int offset, com.android.dx.cf.code.BytecodeArray$Visitor visitor)
Helper to deal with {@code tableswitch}.

param
offset the offset to the {@code tableswitch} opcode itself
param
visitor {@code non-null;} visitor to use
return
instruction length, in bytes

        int at = (offset + 4) & ~3; // "at" skips the padding.

        // Collect the padding.
        int padding = 0;
        for (int i = offset + 1; i < at; i++) {
            padding = (padding << 8) | bytes.getUnsignedByte(i);
        }

        int defaultTarget = offset + bytes.getInt(at);
        int low = bytes.getInt(at + 4);
        int high = bytes.getInt(at + 8);
        int count = high - low + 1;
        at += 12;

        if (low > high) {
            throw new SimException("low / high inversion");
        }

        SwitchList cases = new SwitchList(count);
        for (int i = 0; i < count; i++) {
            int target = offset + bytes.getInt(at);
            at += 4;
            cases.add(low + i, target);
        }
        cases.setDefaultTarget(defaultTarget);
        cases.removeSuperfluousDefaults();
        cases.setImmutable();

        int length = at - offset;
        visitor.visitSwitch(ByteOps.LOOKUPSWITCH, offset, length, cases,
                            padding);

        return length;
private intparseWide(int offset, com.android.dx.cf.code.BytecodeArray$Visitor visitor)
Helper to deal with {@code wide}.

param
offset the offset to the {@code wide} opcode itself
param
visitor {@code non-null;} visitor to use
return
instruction length, in bytes

        int opcode = bytes.getUnsignedByte(offset + 1);
        int idx = bytes.getUnsignedShort(offset + 2);
        switch (opcode) {
            case ByteOps.ILOAD: {
                visitor.visitLocal(ByteOps.ILOAD, offset, 4, idx,
                                   Type.INT, 0);
                return 4;
            }
            case ByteOps.LLOAD: {
                visitor.visitLocal(ByteOps.ILOAD, offset, 4, idx,
                                   Type.LONG, 0);
                return 4;
            }
            case ByteOps.FLOAD: {
                visitor.visitLocal(ByteOps.ILOAD, offset, 4, idx,
                                   Type.FLOAT, 0);
                return 4;
            }
            case ByteOps.DLOAD: {
                visitor.visitLocal(ByteOps.ILOAD, offset, 4, idx,
                                   Type.DOUBLE, 0);
                return 4;
            }
            case ByteOps.ALOAD: {
                visitor.visitLocal(ByteOps.ILOAD, offset, 4, idx,
                                   Type.OBJECT, 0);
                return 4;
            }
            case ByteOps.ISTORE: {
                visitor.visitLocal(ByteOps.ISTORE, offset, 4, idx,
                                   Type.INT, 0);
                return 4;
            }
            case ByteOps.LSTORE: {
                visitor.visitLocal(ByteOps.ISTORE, offset, 4, idx,
                                   Type.LONG, 0);
                return 4;
            }
            case ByteOps.FSTORE: {
                visitor.visitLocal(ByteOps.ISTORE, offset, 4, idx,
                                   Type.FLOAT, 0);
                return 4;
            }
            case ByteOps.DSTORE: {
                visitor.visitLocal(ByteOps.ISTORE, offset, 4, idx,
                                   Type.DOUBLE, 0);
                return 4;
            }
            case ByteOps.ASTORE: {
                visitor.visitLocal(ByteOps.ISTORE, offset, 4, idx,
                                   Type.OBJECT, 0);
                return 4;
            }
            case ByteOps.RET: {
                visitor.visitLocal(opcode, offset, 4, idx,
                                   Type.RETURN_ADDRESS, 0);
                return 4;
            }
            case ByteOps.IINC: {
                int value = bytes.getShort(offset + 4);
                visitor.visitLocal(opcode, offset, 6, idx,
                                   Type.INT, value);
                return 6;
            }
            default: {
                visitor.visitInvalid(ByteOps.WIDE, offset, 1);
                return 1;
            }
        }
public voidprocessWorkSet(int[] workSet, com.android.dx.cf.code.BytecodeArray$Visitor visitor)
Processes the given "work set" by repeatedly finding the lowest bit in the set, clearing it, and parsing and visiting the instruction at the indicated offset (that is, the bit index), repeating until the work set is empty. It is expected that the visitor will regularly set new bits in the work set during the process.

param
workSet {@code non-null;} the work set to process
param
visitor {@code non-null;} visitor to call back to for each instruction

        if (visitor == null) {
            throw new NullPointerException("visitor == null");
        }

        for (;;) {
            int offset = Bits.findFirst(workSet, 0);
            if (offset < 0) {
                break;
            }
            Bits.clear(workSet, offset);
            parseInstruction(offset, visitor);
            visitor.setPreviousOffset(offset);
        }
public intsize()
Gets the size of the bytecode array, per se.

return
{@code >= 0;} the length of the bytecode array

        return bytes.size();