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;
}
private static void forceNotNull(DataFlowRunner runner, DfaMemoryState memState, DfaValue arg) {
if (arg instanceof DfaVariableValue) {
DfaVariableValue var = (DfaVariableValue) arg;
memState.setVarValue(
var, runner.getFactory().createTypeValue(var.getVariableType(), Nullness.NOT_NULL));
}
}
@Override
public DfaInstructionState[] visitCheckReturnValue(
CheckReturnValueInstruction instruction, DataFlowRunner runner, DfaMemoryState memState) {
final DfaValue retValue = memState.pop();
checkNotNullable(
memState, retValue, NullabilityProblem.nullableReturn, instruction.getReturn());
return nextInstruction(instruction, runner, memState);
}
@Override
public DfaInstructionState[] visitFieldReference(
FieldReferenceInstruction instruction, DataFlowRunner runner, DfaMemoryState memState) {
final DfaValue qualifier = memState.pop();
if (!checkNotNullable(
memState, qualifier, NullabilityProblem.fieldAccessNPE, instruction.getElementToAssert())) {
forceNotNull(runner, memState, qualifier);
}
return nextInstruction(instruction, runner, memState);
}
private DfaValue popQualifier(
MethodCallInstruction instruction, DataFlowRunner runner, DfaMemoryState memState) {
@NotNull final DfaValue qualifier = memState.pop();
boolean unboxing = instruction.getMethodType() == MethodCallInstruction.MethodType.UNBOXING;
NullabilityProblem problem =
unboxing ? NullabilityProblem.unboxingNullable : NullabilityProblem.callNPE;
PsiExpression anchor = unboxing ? instruction.getContext() : instruction.getCallExpression();
if (!checkNotNullable(memState, qualifier, problem, anchor)) {
forceNotNull(runner, memState, qualifier);
}
return qualifier;
}
@Override
public DfaInstructionState[] visitTypeCast(
TypeCastInstruction instruction, DataFlowRunner runner, DfaMemoryState memState) {
final DfaValueFactory factory = runner.getFactory();
DfaValue dfaExpr = factory.createValue(instruction.getCasted());
if (dfaExpr != null) {
DfaTypeValue dfaType =
(DfaTypeValue) factory.createTypeValue(instruction.getCastTo(), Nullness.UNKNOWN);
DfaRelationValue dfaInstanceof =
factory.getRelationFactory().createRelation(dfaExpr, dfaType, INSTANCEOF_KEYWORD, false);
if (dfaInstanceof != null && !memState.applyInstanceofOrNull(dfaInstanceof)) {
onInstructionProducesCCE(instruction);
}
}
if (instruction.getCastTo() instanceof PsiPrimitiveType) {
memState.push(runner.getFactory().getBoxedFactory().createUnboxed(memState.pop()));
}
return nextInstruction(instruction, runner, memState);
}
@Override
public DfaInstructionState[] visitAssign(
AssignInstruction instruction, DataFlowRunner runner, DfaMemoryState memState) {
DfaValue dfaSource = memState.pop();
DfaValue dfaDest = memState.pop();
if (dfaDest instanceof DfaVariableValue) {
DfaVariableValue var = (DfaVariableValue) dfaDest;
DfaValueFactory factory = runner.getFactory();
if (dfaSource instanceof DfaVariableValue
&& factory.getVarFactory().getAllQualifiedBy(var).contains(dfaSource)) {
Nullness nullability =
memState.isNotNull(dfaSource)
? Nullness.NOT_NULL
: ((DfaVariableValue) dfaSource).getInherentNullability();
dfaSource =
factory.createTypeValue(((DfaVariableValue) dfaSource).getVariableType(), nullability);
}
if (var.getInherentNullability() == Nullness.NOT_NULL) {
checkNotNullable(
memState,
dfaSource,
NullabilityProblem.assigningToNotNull,
instruction.getRExpression());
}
final PsiModifierListOwner psi = var.getPsiVariable();
if (!(psi instanceof PsiField) || !psi.hasModifierProperty(PsiModifier.VOLATILE)) {
memState.setVarValue(var, dfaSource);
}
} else if (dfaDest instanceof DfaTypeValue && ((DfaTypeValue) dfaDest).isNotNull()) {
checkNotNullable(
memState, dfaSource, NullabilityProblem.assigningToNotNull, instruction.getRExpression());
}
memState.push(dfaDest);
return nextInstruction(instruction, runner, memState);
}
@Override
public DfaInstructionState[] visitBinop(
BinopInstruction instruction, DataFlowRunner runner, DfaMemoryState memState) {
myReachable.add(instruction);
DfaValue dfaRight = memState.pop();
DfaValue dfaLeft = memState.pop();
final IElementType opSign = instruction.getOperationSign();
if (opSign != null) {
DfaInstructionState[] states =
handleConstantComparison(instruction, runner, memState, dfaRight, dfaLeft, opSign);
if (states == null) {
states = handleRelationBinop(instruction, runner, memState, dfaRight, dfaLeft);
}
if (states != null) {
return states;
}
if (PLUS == opSign) {
memState.push(instruction.getNonNullStringValue(runner.getFactory()));
} else {
if (instruction instanceof InstanceofInstruction) {
handleInstanceof((InstanceofInstruction) instruction, dfaRight, dfaLeft);
}
memState.push(DfaUnknownValue.getInstance());
}
} else {
memState.push(DfaUnknownValue.getInstance());
}
instruction.setTrueReachable(); // Not a branching instruction actually.
instruction.setFalseReachable();
return nextInstruction(instruction, runner, memState);
}
@Override
public DfaInstructionState[] visitMethodCall(
final MethodCallInstruction instruction,
final DataFlowRunner runner,
final DfaMemoryState memState) {
DfaValue[] argValues = popCallArguments(instruction, runner, memState);
final DfaValue qualifier = popQualifier(instruction, runner, memState);
List<DfaMemoryState> currentStates = ContainerUtil.newArrayList(memState);
Set<DfaMemoryState> finalStates = ContainerUtil.newLinkedHashSet();
if (argValues != null) {
for (MethodContract contract : instruction.getContracts()) {
currentStates =
addContractResults(
argValues, contract, currentStates, instruction, runner.getFactory(), finalStates);
}
}
for (DfaMemoryState state : currentStates) {
state.push(getMethodResultValue(instruction, qualifier, runner.getFactory()));
finalStates.add(state);
}
return ContainerUtil.map2Array(
finalStates,
DfaInstructionState.class,
new Function<DfaMemoryState, DfaInstructionState>() {
@Override
public DfaInstructionState fun(DfaMemoryState state) {
if (instruction.shouldFlushFields()) {
state.flushFields();
}
return new DfaInstructionState(
runner.getInstruction(instruction.getIndex() + 1), state);
}
});
}
@Override
public DfaInstructionState[] visitPush(
PushInstruction instruction, DataFlowRunner runner, DfaMemoryState memState) {
if (instruction.isReferenceRead()) {
DfaValue dfaValue = instruction.getValue();
if (dfaValue instanceof DfaVariableValue) {
DfaConstValue constValue = memState.getConstantValue((DfaVariableValue) dfaValue);
myPossibleVariableValues.putValue(
instruction,
constValue != null
&& (constValue.getValue() == null || constValue.getValue() instanceof Boolean)
? constValue
: ANY_VALUE);
}
}
return super.visitPush(instruction, runner, memState);
}
@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()]);
}
@Nullable
private DfaValue[] popCallArguments(
MethodCallInstruction instruction, DataFlowRunner runner, DfaMemoryState memState) {
final PsiExpression[] args = instruction.getArgs();
PsiMethod method = instruction.getTargetMethod();
boolean varargCall = instruction.isVarArgCall();
DfaValue[] argValues;
if (method == null || instruction.getContracts().isEmpty()) {
argValues = null;
} else {
int paramCount = method.getParameterList().getParametersCount();
if (paramCount == args.length || method.isVarArgs() && args.length >= paramCount - 1) {
argValues = new DfaValue[paramCount];
if (varargCall) {
argValues[paramCount - 1] = DfaUnknownValue.getInstance();
}
} else {
argValues = null;
}
}
for (int i = 0; i < args.length; i++) {
final DfaValue arg = memState.pop();
int paramIndex = args.length - i - 1;
if (argValues != null && (paramIndex < argValues.length - 1 || !varargCall)) {
argValues[paramIndex] = arg;
}
PsiExpression expr = args[paramIndex];
Nullness requiredNullability = instruction.getArgRequiredNullability(expr);
if (requiredNullability == Nullness.NOT_NULL) {
if (!checkNotNullable(
memState, arg, NullabilityProblem.passingNullableToNotNullParameter, expr)) {
forceNotNull(runner, memState, arg);
}
} else if (requiredNullability == Nullness.UNKNOWN) {
checkNotNullable(
memState, arg, NullabilityProblem.passingNullableArgumentToNonAnnotatedParameter, expr);
}
}
return argValues;
}
@Nullable
private static DfaInstructionState[] checkComparingWithConstant(
BinopInstruction instruction,
DataFlowRunner runner,
DfaMemoryState memState,
DfaVariableValue var,
IElementType opSign,
double comparedWith) {
DfaConstValue knownConstantValue = memState.getConstantValue(var);
Object knownValue = knownConstantValue == null ? null : knownConstantValue.getValue();
if (knownValue instanceof Number) {
double knownDouble = ((Number) knownValue).doubleValue();
return checkComparisonWithKnownRange(
instruction, runner, memState, opSign, comparedWith, knownDouble, knownDouble);
}
PsiType varType = var.getVariableType();
if (!(varType instanceof PsiPrimitiveType)) return null;
if (varType == PsiType.FLOAT || varType == PsiType.DOUBLE) return null;
double minValue =
varType == PsiType.BYTE
? Byte.MIN_VALUE
: varType == PsiType.SHORT
? Short.MIN_VALUE
: varType == PsiType.INT
? Integer.MIN_VALUE
: varType == PsiType.CHAR ? Character.MIN_VALUE : Long.MIN_VALUE;
double maxValue =
varType == PsiType.BYTE
? Byte.MAX_VALUE
: varType == PsiType.SHORT
? Short.MAX_VALUE
: varType == PsiType.INT
? Integer.MAX_VALUE
: varType == PsiType.CHAR ? Character.MAX_VALUE : Long.MAX_VALUE;
return checkComparisonWithKnownRange(
instruction, runner, memState, opSign, comparedWith, minValue, maxValue);
}
private static DfaInstructionState[] alwaysTrue(
BinopInstruction instruction, DataFlowRunner runner, DfaMemoryState memState) {
memState.push(runner.getFactory().getConstFactory().getTrue());
instruction.setTrueReachable();
return nextInstruction(instruction, runner, memState);
}
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;
}