@Nullable
private static DfaInstructionState[] handleConstantComparison(
BinopInstruction instruction,
DataFlowRunner runner,
DfaMemoryState memState,
DfaValue dfaRight,
DfaValue dfaLeft,
IElementType opSign) {
if (dfaRight instanceof DfaConstValue && dfaLeft instanceof DfaVariableValue) {
Object value = ((DfaConstValue) dfaRight).getValue();
if (value instanceof Number) {
DfaInstructionState[] result =
checkComparingWithConstant(
instruction,
runner,
memState,
(DfaVariableValue) dfaLeft,
opSign,
((Number) value).doubleValue());
if (result != null) {
return result;
}
}
}
if (dfaRight instanceof DfaVariableValue && dfaLeft instanceof DfaConstValue) {
return handleConstantComparison(
instruction,
runner,
memState,
dfaLeft,
dfaRight,
DfaRelationValue.getSymmetricOperation(opSign));
}
if (EQEQ != opSign && NE != opSign) {
return null;
}
if (dfaLeft instanceof DfaConstValue && dfaRight instanceof DfaConstValue
|| dfaLeft == runner.getFactory().getConstFactory().getContractFail()
|| dfaRight == runner.getFactory().getConstFactory().getContractFail()) {
boolean negated =
(NE == opSign)
^ (DfaMemoryStateImpl.isNaN(dfaLeft) || DfaMemoryStateImpl.isNaN(dfaRight));
if (dfaLeft == dfaRight ^ negated) {
return alwaysTrue(instruction, runner, memState);
}
return alwaysFalse(instruction, runner, memState);
}
return null;
}
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));
}
}
public DfaInstructionState[] visitConditionalGoto(
ConditionalGotoInstruction instruction, DataFlowRunner runner, DfaMemoryState memState) {
DfaValue cond = memState.pop();
DfaValue condTrue;
DfaValue condFalse;
if (instruction.isNegated()) {
condFalse = cond;
condTrue = cond.createNegated();
} else {
condTrue = cond;
condFalse = cond.createNegated();
}
if (condTrue == runner.getFactory().getConstFactory().getTrue()) {
markBranchReachable(instruction, true);
return new DfaInstructionState[] {
new DfaInstructionState(runner.getInstruction(instruction.getOffset()), memState)
};
}
if (condFalse == runner.getFactory().getConstFactory().getTrue()) {
markBranchReachable(instruction, false);
return nextInstruction(instruction, runner, memState);
}
ArrayList<DfaInstructionState> result = new ArrayList<DfaInstructionState>();
DfaMemoryState thenState = memState.createCopy();
DfaMemoryState elseState = memState.createCopy();
if (thenState.applyCondition(condTrue)) {
result.add(
new DfaInstructionState(runner.getInstruction(instruction.getOffset()), thenState));
markBranchReachable(instruction, true);
}
if (elseState.applyCondition(condFalse)) {
result.add(
new DfaInstructionState(runner.getInstruction(instruction.getIndex() + 1), elseState));
markBranchReachable(instruction, false);
}
return result.toArray(new DfaInstructionState[result.size()]);
}
@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()]);
}
@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[] 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[] 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);
}
private static DfaInstructionState[] alwaysTrue(
BinopInstruction instruction, DataFlowRunner runner, DfaMemoryState memState) {
memState.push(runner.getFactory().getConstFactory().getTrue());
instruction.setTrueReachable();
return nextInstruction(instruction, runner, memState);
}
protected static DfaInstructionState[] nextInstruction(
Instruction instruction, DataFlowRunner runner, DfaMemoryState memState) {
return new DfaInstructionState[] {
new DfaInstructionState(runner.getInstruction(instruction.getIndex() + 1), memState)
};
}