basicverifier.java

asm的源码包 并且包含英文的文档

                expected2 = BasicValue.INT_VALUE;
                break;
            case FALOAD:
                expected1 = newValue(Type.getType("[F"));
                expected2 = BasicValue.INT_VALUE;
                break;
            case DALOAD:
                expected1 = newValue(Type.getType("[D"));
                expected2 = BasicValue.INT_VALUE;
                break;
            case AALOAD:
                expected1 = newValue(Type.getType("[Ljava/lang/Object;"));
                expected2 = BasicValue.INT_VALUE;
                break;
            case IADD:
            case ISUB:
            case IMUL:
            case IDIV:
            case IREM:
            case ISHL:
            case ISHR:
            case IUSHR:
            case IAND:
            case IOR:
            case IXOR:
            case IF_ICMPEQ:
            case IF_ICMPNE:
            case IF_ICMPLT:
            case IF_ICMPGE:
            case IF_ICMPGT:
            case IF_ICMPLE:
                expected1 = BasicValue.INT_VALUE;
                expected2 = BasicValue.INT_VALUE;
                break;
            case FADD:
            case FSUB:
            case FMUL:
            case FDIV:
            case FREM:
            case FCMPL:
            case FCMPG:
                expected1 = BasicValue.FLOAT_VALUE;
                expected2 = BasicValue.FLOAT_VALUE;
                break;
            case LADD:
            case LSUB:
            case LMUL:
            case LDIV:
            case LREM:
            case LAND:
            case LOR:
            case LXOR:
            case LCMP:
                expected1 = BasicValue.LONG_VALUE;
                expected2 = BasicValue.LONG_VALUE;
                break;
            case LSHL:
            case LSHR:
            case LUSHR:
                expected1 = BasicValue.LONG_VALUE;
                expected2 = BasicValue.INT_VALUE;
                break;
            case DADD:
            case DSUB:
            case DMUL:
            case DDIV:
            case DREM:
            case DCMPL:
            case DCMPG:
                expected1 = BasicValue.DOUBLE_VALUE;
                expected2 = BasicValue.DOUBLE_VALUE;
                break;
            case IF_ACMPEQ:
            case IF_ACMPNE:
                expected1 = BasicValue.REFERENCE_VALUE;
                expected2 = BasicValue.REFERENCE_VALUE;
                break;
            case PUTFIELD:
                FieldInsnNode fin = (FieldInsnNode) insn;
                expected1 = newValue(Type.getObjectType(fin.owner));
                expected2 = newValue(Type.getType(fin.desc));
                break;
            default:
                throw new Error("Internal error.");
        }
        if (!isSubTypeOf(value1, expected1)) {
            throw new AnalyzerException("First argument", expected1, value1);
        } else if (!isSubTypeOf(value2, expected2)) {
            throw new AnalyzerException("Second argument", expected2, value2);
        }
        if (insn.getOpcode() == AALOAD) {
            return getElementValue(value1);
        } else {
            return super.binaryOperation(insn, value1, value2);
        }
    }

    public Value ternaryOperation(
        final AbstractInsnNode insn,
        final Value value1,
        final Value value2,
        final Value value3) throws AnalyzerException
    {
        Value expected1;
        Value expected3;
        switch (insn.getOpcode()) {
            case IASTORE:
                expected1 = newValue(Type.getType("[I"));
                expected3 = BasicValue.INT_VALUE;
                break;
            case BASTORE:
                if (!isSubTypeOf(value1, newValue(Type.getType("[Z")))) {
                    expected1 = newValue(Type.getType("[B"));
                } else {
                    expected1 = newValue(Type.getType("[Z"));
                }
                expected3 = BasicValue.INT_VALUE;
                break;
            case CASTORE:
                expected1 = newValue(Type.getType("[C"));
                expected3 = BasicValue.INT_VALUE;
                break;
            case SASTORE:
                expected1 = newValue(Type.getType("[S"));
                expected3 = BasicValue.INT_VALUE;
                break;
            case LASTORE:
                expected1 = newValue(Type.getType("[J"));
                expected3 = BasicValue.LONG_VALUE;
                break;
            case FASTORE:
                expected1 = newValue(Type.getType("[F"));
                expected3 = BasicValue.FLOAT_VALUE;
                break;
            case DASTORE:
                expected1 = newValue(Type.getType("[D"));
                expected3 = BasicValue.DOUBLE_VALUE;
                break;
            case AASTORE:
                expected1 = value1;
                expected3 = BasicValue.REFERENCE_VALUE;
                break;
            default:
                throw new Error("Internal error.");
        }
        if (!isSubTypeOf(value1, expected1)) {
            throw new AnalyzerException("First argument", "a " + expected1
                    + " array reference", value1);
        } else if (value2 != BasicValue.INT_VALUE) {
            throw new AnalyzerException("Second argument",
                    BasicValue.INT_VALUE,
                    value2);
        } else if (!isSubTypeOf(value3, expected3)) {
            throw new AnalyzerException("Third argument", expected3, value3);
        }
        return null;
    }

    public Value naryOperation(final AbstractInsnNode insn, final List values)
            throws AnalyzerException
    {
        int opcode = insn.getOpcode();
        if (opcode == MULTIANEWARRAY) {
            for (int i = 0; i < values.size(); ++i) {
                if (values.get(i) != BasicValue.INT_VALUE) {
                    throw new AnalyzerException(null,
                            BasicValue.INT_VALUE,
                            (Value) values.get(i));
                }
            }
        } else {
            int i = 0;
            int j = 0;
            if (opcode != INVOKESTATIC) {
                String own = ((MethodInsnNode) insn).owner;
                if (own.charAt(0) != '[') { // can happen with JDK1.5 clone()
                    own = "L" + own + ";";
                }
                Type owner = Type.getType(own);
                if (!isSubTypeOf((Value) values.get(i++), newValue(owner))) {
                    throw new AnalyzerException("Method owner",
                            newValue(owner),
                            (Value) values.get(0));
                }
            }
            Type[] args = Type.getArgumentTypes(((MethodInsnNode) insn).desc);
            while (i < values.size()) {
                Value expected = newValue(args[j++]);
                Value encountered = (Value) values.get(i++);
                if (!isSubTypeOf(encountered, expected)) {
                    throw new AnalyzerException("Argument " + j,
                            expected,
                            encountered);
                }
            }
        }
        return super.naryOperation(insn, values);
    }

    protected boolean isArrayValue(final Value value) {
        return ((BasicValue) value).isReference();
    }

    protected Value getElementValue(final Value objectArrayValue)
            throws AnalyzerException
    {
        return BasicValue.REFERENCE_VALUE;
    }

    protected boolean isSubTypeOf(final Value value, final Value expected) {
        return value == expected;
    }
}