private DfaValue getDfaContractReturnValue(
MethodContract contract, MethodCallInstruction instruction, DfaValueFactory factory) {
switch (contract.returnValue) {
case NULL_VALUE:
return factory.getConstFactory().getNull();
case NOT_NULL_VALUE:
return factory.createTypeValue(instruction.getResultType(), Nullness.NOT_NULL);
case TRUE_VALUE:
return factory.getConstFactory().getTrue();
case FALSE_VALUE:
return factory.getConstFactory().getFalse();
case THROW_EXCEPTION:
return factory.getConstFactory().getContractFail();
default:
return getMethodResultValue(instruction, null, factory);
}
}
@Nullable
private DfaInstructionState[] handleRelationBinop(
BinopInstruction instruction,
DataFlowRunner runner,
DfaMemoryState memState,
DfaValue dfaRight,
DfaValue dfaLeft) {
DfaValueFactory factory = runner.getFactory();
final Instruction next = runner.getInstruction(instruction.getIndex() + 1);
DfaRelationValue dfaRelation =
factory
.getRelationFactory()
.createRelation(dfaLeft, dfaRight, instruction.getOperationSign(), false);
if (dfaRelation == null) {
return null;
}
myCanBeNullInInstanceof.add(instruction);
ArrayList<DfaInstructionState> states = new ArrayList<DfaInstructionState>();
final DfaMemoryState trueCopy = memState.createCopy();
if (trueCopy.applyCondition(dfaRelation)) {
trueCopy.push(factory.getConstFactory().getTrue());
instruction.setTrueReachable();
states.add(new DfaInstructionState(next, trueCopy));
}
//noinspection UnnecessaryLocalVariable
DfaMemoryState falseCopy = memState;
if (falseCopy.applyCondition(dfaRelation.createNegated())) {
falseCopy.push(factory.getConstFactory().getFalse());
instruction.setFalseReachable();
states.add(new DfaInstructionState(next, falseCopy));
if (instruction instanceof InstanceofInstruction && !falseCopy.isNull(dfaLeft)) {
myUsefulInstanceofs.add((InstanceofInstruction) instruction);
}
}
return states.toArray(new DfaInstructionState[states.size()]);
}
protected boolean checkNotNullable(
DfaMemoryState state, DfaValue value, NullabilityProblem problem, PsiElement anchor) {
boolean notNullable = state.checkNotNullable(value);
if (notNullable
&& problem != NullabilityProblem.passingNullableArgumentToNonAnnotatedParameter) {
DfaValueFactory factory = ((DfaMemoryStateImpl) state).getFactory();
state.applyCondition(
factory
.getRelationFactory()
.createRelation(value, factory.getConstFactory().getNull(), NE, false));
}
return notNullable;
}
@NotNull
private DfaValue getMethodResultValue(
MethodCallInstruction instruction,
@Nullable DfaValue qualifierValue,
DfaValueFactory factory) {
DfaValue precalculated = instruction.getPrecalculatedReturnValue();
if (precalculated != null) {
return precalculated;
}
final PsiType type = instruction.getResultType();
final MethodCallInstruction.MethodType methodType = instruction.getMethodType();
if (methodType == MethodCallInstruction.MethodType.UNBOXING) {
return factory.getBoxedFactory().createUnboxed(qualifierValue);
}
if (methodType == MethodCallInstruction.MethodType.BOXING) {
DfaValue boxed = factory.getBoxedFactory().createBoxed(qualifierValue);
return boxed == null ? factory.createTypeValue(type, Nullness.NOT_NULL) : boxed;
}
if (methodType == MethodCallInstruction.MethodType.CAST) {
assert qualifierValue != null;
if (qualifierValue instanceof DfaConstValue) {
Object casted =
TypeConversionUtil.computeCastTo(((DfaConstValue) qualifierValue).getValue(), type);
return factory
.getConstFactory()
.createFromValue(casted, type, ((DfaConstValue) qualifierValue).getConstant());
}
return qualifierValue;
}
if (type != null && (type instanceof PsiClassType || type.getArrayDimensions() > 0)) {
Nullness nullability = myReturnTypeNullability.get(instruction);
if (nullability == Nullness.UNKNOWN && factory.isUnknownMembersAreNullable()) {
nullability = Nullness.NULLABLE;
}
return factory.createTypeValue(type, nullability);
}
return DfaUnknownValue.getInstance();
}
private List<DfaMemoryState> addContractResults(
DfaValue[] argValues,
MethodContract contract,
List<DfaMemoryState> states,
MethodCallInstruction instruction,
DfaValueFactory factory,
Set<DfaMemoryState> finalStates) {
DfaConstValue.Factory constFactory = factory.getConstFactory();
List<DfaMemoryState> falseStates = ContainerUtil.newArrayList();
for (int i = 0; i < argValues.length; i++) {
DfaValue argValue = argValues[i];
MethodContract.ValueConstraint constraint = contract.arguments[i];
DfaConstValue expectedValue = constraint.getComparisonValue(factory);
if (expectedValue == null) continue;
boolean invertCondition = constraint.shouldUseNonEqComparison();
DfaValue condition =
factory
.getRelationFactory()
.createRelation(argValue, expectedValue, EQEQ, invertCondition);
if (condition == null) {
if (!(argValue instanceof DfaConstValue)) {
for (DfaMemoryState state : states) {
falseStates.add(state.createCopy());
}
continue;
}
condition =
constFactory.createFromValue(
(argValue == expectedValue) != invertCondition, PsiType.BOOLEAN, null);
}
List<DfaMemoryState> nextStates = ContainerUtil.newArrayList();
for (DfaMemoryState state : states) {
boolean unknownVsNull =
expectedValue == constFactory.getNull()
&& argValue instanceof DfaVariableValue
&& ((DfaMemoryStateImpl) state)
.getVariableState((DfaVariableValue) argValue)
.getNullability()
== Nullness.UNKNOWN;
DfaMemoryState falseCopy = state.createCopy();
if (state.applyCondition(condition)) {
if (unknownVsNull && !invertCondition) {
state.markEphemeral();
}
nextStates.add(state);
}
if (falseCopy.applyCondition(condition.createNegated())) {
if (unknownVsNull && invertCondition) {
falseCopy.markEphemeral();
}
falseStates.add(falseCopy);
}
}
states = nextStates;
}
for (DfaMemoryState state : states) {
state.push(getDfaContractReturnValue(contract, instruction, factory));
finalStates.add(state);
}
return falseStates;
}