@NotNull
@Override
public BasicValue merge(@NotNull BasicValue v, @NotNull BasicValue w) {
if (v.equals(w)) return v;
if (tolerantToUninitializedValues) {
if (v == StrictBasicValue.UNINITIALIZED_VALUE) return w;
if (w == StrictBasicValue.UNINITIALIZED_VALUE) return v;
} else if (v == StrictBasicValue.UNINITIALIZED_VALUE
|| w == StrictBasicValue.UNINITIALIZED_VALUE) {
return StrictBasicValue.UNINITIALIZED_VALUE;
}
// if merge of two references then `lub` is java/lang/Object
// arrays also are BasicValues with reference type's
if (isReference(v) && isReference(w)) {
return StrictBasicValue.REFERENCE_VALUE;
}
// if merge of something can be stored in int var (int, char, boolean, byte, character)
if (v.getType().getOpcode(Opcodes.ISTORE) == Opcodes.ISTORE
&& w.getType().getOpcode(Opcodes.ISTORE) == Opcodes.ISTORE) {
return StrictBasicValue.INT_VALUE;
}
return StrictBasicValue.UNINITIALIZED_VALUE;
}
private static boolean isReference(@NotNull BasicValue v) {
return v.getType().getSort() == Type.OBJECT || v.getType().getSort() == Type.ARRAY;
}
@Override
public BasicValue binaryOperation(
@NotNull AbstractInsnNode insn, @NotNull BasicValue value1, @NotNull BasicValue value2)
throws AnalyzerException {
if (insn.getOpcode() == Opcodes.AALOAD) {
Type arrayType = value1.getType();
if (arrayType != null && arrayType.getSort() == Type.ARRAY) {
return new StrictBasicValue(arrayType.getElementType());
}
}
switch (insn.getOpcode()) {
case IALOAD:
case BALOAD:
case CALOAD:
case SALOAD:
case IADD:
case ISUB:
case IMUL:
case IDIV:
case IREM:
case ISHL:
case ISHR:
case IUSHR:
case IAND:
case IOR:
case IXOR:
return StrictBasicValue.INT_VALUE;
case FALOAD:
case FADD:
case FSUB:
case FMUL:
case FDIV:
case FREM:
return StrictBasicValue.FLOAT_VALUE;
case LALOAD:
case LADD:
case LSUB:
case LMUL:
case LDIV:
case LREM:
case LSHL:
case LSHR:
case LUSHR:
case LAND:
case LOR:
case LXOR:
return StrictBasicValue.LONG_VALUE;
case DALOAD:
case DADD:
case DSUB:
case DMUL:
case DDIV:
case DREM:
return StrictBasicValue.DOUBLE_VALUE;
case AALOAD:
return StrictBasicValue.REFERENCE_VALUE;
case LCMP:
case FCMPL:
case FCMPG:
case DCMPL:
case DCMPG:
return StrictBasicValue.INT_VALUE;
case IF_ICMPEQ:
case IF_ICMPNE:
case IF_ICMPLT:
case IF_ICMPGE:
case IF_ICMPGT:
case IF_ICMPLE:
case IF_ACMPEQ:
case IF_ACMPNE:
case PUTFIELD:
return null;
default:
throw new Error("Internal error.");
}
}