@NotNull
private KotlinTypeInfo getTypeInfoWhenOnlyOneBranchIsPresent(
@NotNull KtExpression presentBranch,
@NotNull LexicalWritableScope presentScope,
@NotNull DataFlowInfo presentInfo,
@NotNull DataFlowInfo otherInfo,
@NotNull ExpressionTypingContext context,
@NotNull KtIfExpression ifExpression,
boolean isStatement) {
ExpressionTypingContext newContext =
context
.replaceDataFlowInfo(presentInfo)
.replaceExpectedType(NO_EXPECTED_TYPE)
.replaceContextDependency(INDEPENDENT);
KotlinTypeInfo typeInfo =
components.expressionTypingServices.getBlockReturnedTypeWithWritableScope(
presentScope,
Collections.singletonList(presentBranch),
CoercionStrategy.NO_COERCION,
newContext);
KotlinType type = typeInfo.getType();
DataFlowInfo dataFlowInfo;
if (type != null && KotlinBuiltIns.isNothing(type)) {
dataFlowInfo = otherInfo;
} else {
dataFlowInfo = typeInfo.getDataFlowInfo().or(otherInfo);
}
return components
.dataFlowAnalyzer
.checkImplicitCast(
components.dataFlowAnalyzer.checkType(
typeInfo.replaceType(components.builtIns.getUnitType()), ifExpression, context),
ifExpression,
context,
isStatement)
.replaceDataFlowInfo(dataFlowInfo);
}
/**
* Visits block statements propagating data flow information from the first to the last.
* Determines block returned type and data flow information at the end of the block AND at the
* nearest jump point from the block beginning.
*/
/*package*/ KotlinTypeInfo getBlockReturnedTypeWithWritableScope(
@NotNull LexicalWritableScope scope,
@NotNull List<? extends KtElement> block,
@NotNull CoercionStrategy coercionStrategyForLastExpression,
@NotNull ExpressionTypingContext context) {
if (block.isEmpty()) {
return TypeInfoFactoryKt.createTypeInfo(
expressionTypingComponents.builtIns.getUnitType(), context);
}
ExpressionTypingInternals blockLevelVisitor =
new ExpressionTypingVisitorDispatcher.ForBlock(
expressionTypingComponents, annotationChecker, scope);
ExpressionTypingContext newContext =
context.replaceScope(scope).replaceExpectedType(NO_EXPECTED_TYPE);
KotlinTypeInfo result = TypeInfoFactoryKt.noTypeInfo(context);
// Jump point data flow info
DataFlowInfo beforeJumpInfo = newContext.dataFlowInfo;
boolean jumpOutPossible = false;
for (Iterator<? extends KtElement> iterator = block.iterator(); iterator.hasNext(); ) {
KtElement statement = iterator.next();
if (!(statement instanceof KtExpression)) {
continue;
}
KtExpression statementExpression = (KtExpression) statement;
if (!iterator.hasNext()) {
result =
getTypeOfLastExpressionInBlock(
statementExpression,
newContext.replaceExpectedType(context.expectedType),
coercionStrategyForLastExpression,
blockLevelVisitor);
if (result.getType() != null
&& statementExpression.getParent() instanceof KtBlockExpression) {
DataFlowValue lastExpressionValue =
DataFlowValueFactory.createDataFlowValue(
statementExpression, result.getType(), context);
DataFlowValue blockExpressionValue =
DataFlowValueFactory.createDataFlowValue(
(KtBlockExpression) statementExpression.getParent(), result.getType(), context);
result =
result.replaceDataFlowInfo(
result.getDataFlowInfo().assign(blockExpressionValue, lastExpressionValue));
}
} else {
result =
blockLevelVisitor.getTypeInfo(
statementExpression,
newContext.replaceContextDependency(ContextDependency.INDEPENDENT),
true);
}
DataFlowInfo newDataFlowInfo = result.getDataFlowInfo();
// If jump is not possible, we take new data flow info before jump
if (!jumpOutPossible) {
beforeJumpInfo = result.getJumpFlowInfo();
jumpOutPossible = result.getJumpOutPossible();
}
if (newDataFlowInfo != context.dataFlowInfo) {
newContext = newContext.replaceDataFlowInfo(newDataFlowInfo);
// We take current data flow info if jump there is not possible
}
blockLevelVisitor =
new ExpressionTypingVisitorDispatcher.ForBlock(
expressionTypingComponents, annotationChecker, scope);
}
return result.replaceJumpOutPossible(jumpOutPossible).replaceJumpFlowInfo(beforeJumpInfo);
}
public KotlinTypeInfo visitForExpression(
KtForExpression expression,
ExpressionTypingContext contextWithExpectedType,
boolean isStatement) {
if (!isStatement)
return components.dataFlowAnalyzer.illegalStatementType(
expression, contextWithExpectedType, facade);
ExpressionTypingContext context =
contextWithExpectedType
.replaceExpectedType(NO_EXPECTED_TYPE)
.replaceContextDependency(INDEPENDENT);
// Preliminary analysis
PreliminaryLoopVisitor loopVisitor = PreliminaryLoopVisitor.visitLoop(expression);
context =
context.replaceDataFlowInfo(
loopVisitor.clearDataFlowInfoForAssignedLocalVariables(context.dataFlowInfo));
KtExpression loopRange = expression.getLoopRange();
KotlinType expectedParameterType = null;
KotlinTypeInfo loopRangeInfo;
if (loopRange != null) {
ExpressionReceiver loopRangeReceiver =
getExpressionReceiver(facade, loopRange, context.replaceScope(context.scope));
loopRangeInfo = facade.getTypeInfo(loopRange, context);
if (loopRangeReceiver != null) {
expectedParameterType =
components.forLoopConventionsChecker.checkIterableConvention(
loopRangeReceiver, context);
}
} else {
loopRangeInfo = TypeInfoFactoryKt.noTypeInfo(context);
}
LexicalWritableScope loopScope = newWritableScopeImpl(context, "Scope with for-loop index");
KtParameter loopParameter = expression.getLoopParameter();
if (loopParameter != null) {
VariableDescriptor variableDescriptor =
createLoopParameterDescriptor(loopParameter, expectedParameterType, context);
components
.modifiersChecker
.withTrace(context.trace)
.checkModifiersForLocalDeclaration(loopParameter, variableDescriptor);
components.identifierChecker.checkDeclaration(loopParameter, context.trace);
loopScope.addVariableDescriptor(variableDescriptor);
} else {
KtMultiDeclaration multiParameter = expression.getMultiParameter();
if (multiParameter != null && loopRange != null) {
KotlinType elementType =
expectedParameterType == null
? ErrorUtils.createErrorType("Loop range has no type")
: expectedParameterType;
TransientReceiver iteratorNextAsReceiver = new TransientReceiver(elementType);
components.annotationResolver.resolveAnnotationsWithArguments(
loopScope, multiParameter.getModifierList(), context.trace);
components.multiDeclarationResolver.defineLocalVariablesFromMultiDeclaration(
loopScope, multiParameter, iteratorNextAsReceiver, loopRange, context);
components
.modifiersChecker
.withTrace(context.trace)
.checkModifiersForMultiDeclaration(multiParameter);
components
.modifiersChecker
.withTrace(context.trace)
.checkParameterHasNoValOrVar(multiParameter, VAL_OR_VAR_ON_LOOP_MULTI_PARAMETER);
components.identifierChecker.checkDeclaration(multiParameter, context.trace);
}
}
KtExpression body = expression.getBody();
KotlinTypeInfo bodyTypeInfo;
if (body != null) {
bodyTypeInfo =
components.expressionTypingServices.getBlockReturnedTypeWithWritableScope(
loopScope,
Collections.singletonList(body),
CoercionStrategy.NO_COERCION,
context.replaceDataFlowInfo(loopRangeInfo.getDataFlowInfo()));
} else {
bodyTypeInfo = loopRangeInfo;
}
return components
.dataFlowAnalyzer
.checkType(
bodyTypeInfo.replaceType(components.builtIns.getUnitType()),
expression,
contextWithExpectedType)
.replaceDataFlowInfo(loopRangeInfo.getDataFlowInfo());
}
public KotlinTypeInfo visitDoWhileExpression(
KtDoWhileExpression expression,
ExpressionTypingContext contextWithExpectedType,
boolean isStatement) {
if (!isStatement)
return components.dataFlowAnalyzer.illegalStatementType(
expression, contextWithExpectedType, facade);
ExpressionTypingContext context =
contextWithExpectedType
.replaceExpectedType(NO_EXPECTED_TYPE)
.replaceContextDependency(INDEPENDENT);
KtExpression body = expression.getBody();
LexicalScope conditionScope = context.scope;
// Preliminary analysis
PreliminaryLoopVisitor loopVisitor = PreliminaryLoopVisitor.visitLoop(expression);
context =
context.replaceDataFlowInfo(
loopVisitor.clearDataFlowInfoForAssignedLocalVariables(context.dataFlowInfo));
// Here we must record data flow information at the end of the body (or at the first jump, to be
// precise) and
// .and it with entrance data flow information, because do-while body is executed at least once
// See KT-6283
KotlinTypeInfo bodyTypeInfo;
if (body instanceof KtFunctionLiteralExpression) {
// As a matter of fact, function literal is always unused at this point
bodyTypeInfo = facade.getTypeInfo(body, context.replaceScope(context.scope));
} else if (body != null) {
LexicalWritableScope writableScope = newWritableScopeImpl(context, "do..while body scope");
conditionScope = writableScope;
List<KtExpression> block;
if (body instanceof KtBlockExpression) {
block = ((KtBlockExpression) body).getStatements();
} else {
block = Collections.singletonList(body);
}
bodyTypeInfo =
components.expressionTypingServices.getBlockReturnedTypeWithWritableScope(
writableScope, block, CoercionStrategy.NO_COERCION, context);
} else {
bodyTypeInfo = TypeInfoFactoryKt.noTypeInfo(context);
}
KtExpression condition = expression.getCondition();
DataFlowInfo conditionDataFlowInfo = checkCondition(conditionScope, condition, context);
DataFlowInfo dataFlowInfo;
// Without jumps out, condition is entered and false, with jumps out, we know nothing about it
if (!containsJumpOutOfLoop(expression, context)) {
dataFlowInfo =
components
.dataFlowAnalyzer
.extractDataFlowInfoFromCondition(condition, false, context)
.and(conditionDataFlowInfo);
} else {
dataFlowInfo = context.dataFlowInfo;
}
// Here we must record data flow information at the end of the body (or at the first jump, to be
// precise) and
// .and it with entrance data flow information, because do-while body is executed at least once
// See KT-6283
// NB: it's really important to do it for non-empty body which is not a function literal
// If it's a function literal, it appears always unused so it's no matter what we do at this
// point
if (body != null) {
// We should take data flow info from the first jump point,
// but without affecting changing variables
dataFlowInfo =
dataFlowInfo.and(
loopVisitor.clearDataFlowInfoForAssignedLocalVariables(
bodyTypeInfo.getJumpFlowInfo()));
}
return components
.dataFlowAnalyzer
.checkType(
bodyTypeInfo.replaceType(components.builtIns.getUnitType()),
expression,
contextWithExpectedType)
.replaceDataFlowInfo(dataFlowInfo);
}
public KotlinTypeInfo visitWhileExpression(
KtWhileExpression expression,
ExpressionTypingContext contextWithExpectedType,
boolean isStatement) {
if (!isStatement)
return components.dataFlowAnalyzer.illegalStatementType(
expression, contextWithExpectedType, facade);
ExpressionTypingContext context =
contextWithExpectedType
.replaceExpectedType(NO_EXPECTED_TYPE)
.replaceContextDependency(INDEPENDENT);
// Preliminary analysis
PreliminaryLoopVisitor loopVisitor = PreliminaryLoopVisitor.visitLoop(expression);
context =
context.replaceDataFlowInfo(
loopVisitor.clearDataFlowInfoForAssignedLocalVariables(context.dataFlowInfo));
KtExpression condition = expression.getCondition();
// Extract data flow info from condition itself without taking value into account
DataFlowInfo dataFlowInfo = checkCondition(context.scope, condition, context);
KtExpression body = expression.getBody();
KotlinTypeInfo bodyTypeInfo;
DataFlowInfo conditionInfo =
components
.dataFlowAnalyzer
.extractDataFlowInfoFromCondition(condition, true, context)
.and(dataFlowInfo);
if (body != null) {
LexicalWritableScope scopeToExtend =
newWritableScopeImpl(context, "Scope extended in while's condition");
bodyTypeInfo =
components.expressionTypingServices.getBlockReturnedTypeWithWritableScope(
scopeToExtend,
Collections.singletonList(body),
CoercionStrategy.NO_COERCION,
context.replaceDataFlowInfo(conditionInfo));
} else {
bodyTypeInfo = TypeInfoFactoryKt.noTypeInfo(conditionInfo);
}
// Condition is false at this point only if there is no jumps outside
if (!containsJumpOutOfLoop(expression, context)) {
dataFlowInfo =
components
.dataFlowAnalyzer
.extractDataFlowInfoFromCondition(condition, false, context)
.and(dataFlowInfo);
}
// Special case: while (true)
// In this case we must record data flow information at the nearest break / continue and
// .and it with entrance data flow information, because while body until break is executed at
// least once in this case
// See KT-6284
if (body != null && KtPsiUtil.isTrueConstant(condition)) {
// We should take data flow info from the first jump point,
// but without affecting changing variables
dataFlowInfo =
dataFlowInfo.and(
loopVisitor.clearDataFlowInfoForAssignedLocalVariables(
bodyTypeInfo.getJumpFlowInfo()));
}
return components
.dataFlowAnalyzer
.checkType(
bodyTypeInfo.replaceType(components.builtIns.getUnitType()),
expression,
contextWithExpectedType)
.replaceDataFlowInfo(dataFlowInfo);
}