[FIR] Add FirDelegateUsesExtensionPropertyTypeParameterChecker

compiler/fir/checkers/checkers-component-generator/src/org/jetbrains/kotlin/fir/checkers/generator/diagnostics/FirDiagnosticsList.kt

@@ -891,6 +891,8 @@ object DIAGNOSTICS_LIST : DiagnosticList("FirErrors") {
             parameter<ConeKotlinType>("expectedType")
             parameter<ConeKotlinType>("actualType")
         }
+        val DELEGATE_USES_EXTENSION_PROPERTY_TYPE_PARAMETER by error<KtProperty>(PositioningStrategy.PROPERTY_DELEGATE)
+        val DELEGATE_USES_EXTENSION_PROPERTY_TYPE_PARAMETER_WARNING by warning<KtProperty>(PositioningStrategy.PROPERTY_DELEGATE)
         val INITIALIZER_TYPE_MISMATCH by error<KtProperty>(PositioningStrategy.PROPERTY_INITIALIZER) {
             parameter<ConeKotlinType>("expectedType")
             parameter<ConeKotlinType>("actualType")

compiler/fir/checkers/gen/org/jetbrains/kotlin/fir/analysis/diagnostics/FirErrors.kt

@@ -487,6 +487,8 @@ object FirErrors {
     val CONST_VAL_WITHOUT_INITIALIZER by error0<KtProperty>(SourceElementPositioningStrategies.CONST_MODIFIER)
     val CONST_VAL_WITH_NON_CONST_INITIALIZER by error0<KtExpression>()
     val WRONG_SETTER_PARAMETER_TYPE by error2<KtTypeReference, ConeKotlinType, ConeKotlinType>()
+    val DELEGATE_USES_EXTENSION_PROPERTY_TYPE_PARAMETER by error0<KtProperty>(SourceElementPositioningStrategies.PROPERTY_DELEGATE)
+    val DELEGATE_USES_EXTENSION_PROPERTY_TYPE_PARAMETER_WARNING by warning0<KtProperty>(SourceElementPositioningStrategies.PROPERTY_DELEGATE)
     val INITIALIZER_TYPE_MISMATCH by error3<KtProperty, ConeKotlinType, ConeKotlinType, Boolean>(SourceElementPositioningStrategies.PROPERTY_INITIALIZER)
     val GETTER_VISIBILITY_DIFFERS_FROM_PROPERTY_VISIBILITY by error0<KtModifierListOwner>(SourceElementPositioningStrategies.VISIBILITY_MODIFIER)
     val SETTER_VISIBILITY_INCONSISTENT_WITH_PROPERTY_VISIBILITY by error0<KtModifierListOwner>(SourceElementPositioningStrategies.VISIBILITY_MODIFIER)

compiler/fir/checkers/src/org/jetbrains/kotlin/fir/analysis/checkers/CommonDeclarationCheckers.kt

@@ -60,6 +60,7 @@ object CommonDeclarationCheckers : DeclarationCheckers() {
             FirInlinePropertyChecker,
             FirPropertyFromParameterChecker,
             FirLocalVariableTypeParametersSyntaxChecker,
+            FirDelegateUsesExtensionPropertyTypeParameterChecker,
         )
 
     override val backingFieldCheckers: Set<FirBackingFieldChecker>

compiler/fir/checkers/src/org/jetbrains/kotlin/fir/analysis/checkers/declaration/FirDelegateUsesExtensionPropertyTypeParameterChecker.kt

@@ -0,0 +1,66 @@
+/*
+ * Copyright 2010-2020 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.fir.analysis.checkers.declaration
+
+import org.jetbrains.kotlin.config.LanguageFeature
+import org.jetbrains.kotlin.fir.analysis.checkers.context.CheckerContext
+import org.jetbrains.kotlin.fir.analysis.diagnostics.DiagnosticReporter
+import org.jetbrains.kotlin.fir.analysis.diagnostics.FirDiagnosticFactory0
+import org.jetbrains.kotlin.fir.analysis.diagnostics.FirErrors
+import org.jetbrains.kotlin.fir.analysis.diagnostics.reportOn
+import org.jetbrains.kotlin.fir.declarations.FirProperty
+import org.jetbrains.kotlin.fir.expressions.FirFunctionCall
+import org.jetbrains.kotlin.fir.languageVersionSettings
+import org.jetbrains.kotlin.fir.symbols.impl.FirTypeParameterSymbol
+import org.jetbrains.kotlin.fir.types.*
+import org.jetbrains.kotlin.utils.addToStdlib.safeAs
+
+object FirDelegateUsesExtensionPropertyTypeParameterChecker : FirPropertyChecker() {
+    override fun check(declaration: FirProperty, context: CheckerContext, reporter: DiagnosticReporter) {
+        val delegate = declaration.delegate.safeAs<FirFunctionCall>() ?: return
+        val parameters = declaration.typeParameters.mapTo(hashSetOf()) { it.symbol }
+
+        val shouldReportError = delegate.typeRef.coneType.containsTypeParameterFrom(parameters, delegate, context, reporter)
+
+        if (shouldReportError) {
+            val diagnostic = getProperDiagnostic(context)
+            reporter.reportOn(declaration.source, diagnostic, context)
+        }
+    }
+
+    private fun getProperDiagnostic(context: CheckerContext): FirDiagnosticFactory0 {
+        val reportAsError = context.session.languageVersionSettings.supportsFeature(
+            LanguageFeature.ForbidUsingExtensionPropertyTypeParameterInDelegate
+        )
+
+        return if (reportAsError) {
+            FirErrors.DELEGATE_USES_EXTENSION_PROPERTY_TYPE_PARAMETER
+        } else {
+            FirErrors.DELEGATE_USES_EXTENSION_PROPERTY_TYPE_PARAMETER_WARNING
+        }
+    }
+
+    private fun ConeKotlinType.containsTypeParameterFrom(
+        parameters: HashSet<FirTypeParameterSymbol>,
+        delegate: FirFunctionCall,
+        context: CheckerContext,
+        reporter: DiagnosticReporter,
+    ): Boolean {
+        for (it in typeArguments) {
+            val theType = it.type ?: continue
+            val symbol = theType.toSymbol(context.session)
+
+            if (
+                symbol in parameters ||
+                theType.containsTypeParameterFrom(parameters, delegate, context, reporter)
+            ) {
+                return true
+            }
+        }
+
+        return false
+    }
+}