org.jetbrains.kotlin.resolve.calls.checkers.ResultTypeWithNullableOperatorsChecker.kt Maven / Gradle / Ivy
/*
* Copyright 2010-2018 JetBrains s.r.o. and Kotlin Programming Language contributors.
* Use of this source code is governed by the Apache 2.0 license that can be found in the license/LICENSE.txt file.
*/
package org.jetbrains.kotlin.resolve.calls.checkers
import com.intellij.psi.PsiElement
import org.jetbrains.kotlin.config.LanguageFeature
import org.jetbrains.kotlin.diagnostics.Errors
import org.jetbrains.kotlin.diagnostics.reportDiagnosticOnce
import org.jetbrains.kotlin.lexer.KtTokens
import org.jetbrains.kotlin.psi.KtBinaryExpression
import org.jetbrains.kotlin.resolve.calls.model.ResolvedCall
import org.jetbrains.kotlin.resolve.checkers.isResultType
import org.jetbrains.kotlin.types.expressions.ControlStructureTypingUtils
class ResultTypeWithNullableOperatorsChecker : CallChecker {
override fun check(resolvedCall: ResolvedCall<*>, reportOn: PsiElement, context: CallCheckerContext) {
if (context.languageVersionSettings.supportsFeature(LanguageFeature.AllowNullOperatorsForResult)) return
val name = resolvedCall.resultingDescriptor.name
val operationNode = resolvedCall.call.callOperationNode
when {
operationNode?.elementType == KtTokens.SAFE_ACCESS -> {
val resultingDescriptor = resolvedCall.resultingDescriptor
val receiver = resultingDescriptor.extensionReceiverParameter ?: resultingDescriptor.dispatchReceiverParameter ?: return
if (receiver.type.isResultType()) {
context.trace.report(Errors.RESULT_CLASS_WITH_NULLABLE_OPERATOR.on(operationNode!!.psi, "?."))
}
}
name == ControlStructureTypingUtils.ResolveConstruct.EXCL_EXCL.specialFunctionName -> {
if (resolvedCall.resultingDescriptor.returnType?.isResultType() == true) {
context.trace.report(Errors.RESULT_CLASS_WITH_NULLABLE_OPERATOR.on(reportOn, "!!"))
}
}
name == ControlStructureTypingUtils.ResolveConstruct.ELVIS.specialFunctionName -> {
val elvisBinaryExpression = resolvedCall.call.callElement as? KtBinaryExpression ?: return
val left = elvisBinaryExpression.left ?: return
val leftType = context.trace.getType(left) ?: return
if (leftType.isResultType()) {
context.trace.reportDiagnosticOnce(Errors.RESULT_CLASS_WITH_NULLABLE_OPERATOR.on(reportOn, "?:"))
}
// Additional check for case `a ?: b ?: c`, where `b` is Result
// This is needed because inference will give common supertype for `a ?: b` which might not be Result
if (left is KtBinaryExpression) {
val lastExpression = left.right ?: return
val lastExpressionType = context.trace.getType(lastExpression) ?: return
if (lastExpressionType.isResultType()) {
context.trace.reportDiagnosticOnce(Errors.RESULT_CLASS_WITH_NULLABLE_OPERATOR.on(reportOn, "?:"))
}
}
}
}
}
}