FIR: add checker for local extension properties

^KT-56013 Fixed

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

@@ -1035,6 +1035,8 @@ object DIAGNOSTICS_LIST : DiagnosticList("FirErrors") {
         val LATEINIT_INTRINSIC_CALL_ON_NON_ACCESSIBLE_PROPERTY by error<PsiElement>() {
             parameter<Symbol>("declaration")
         }
+
+        val LOCAL_EXTENSION_PROPERTY by error<PsiElement>()
     }
 
     val MPP_PROJECTS by object : DiagnosticGroup("Multi-platform projects") {

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

@@ -565,6 +565,7 @@ object FirErrors {
     val LATEINIT_INTRINSIC_CALL_ON_NON_LATEINIT by error0<PsiElement>()
     val LATEINIT_INTRINSIC_CALL_IN_INLINE_FUNCTION by error0<PsiElement>()
     val LATEINIT_INTRINSIC_CALL_ON_NON_ACCESSIBLE_PROPERTY by error1<PsiElement, FirBasedSymbol<*>>()
+    val LOCAL_EXTENSION_PROPERTY by error0<PsiElement>()
 
     // Multi-platform projects
     val EXPECTED_DECLARATION_WITH_BODY by error0<KtDeclaration>(SourceElementPositioningStrategies.DECLARATION_SIGNATURE)

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

@@ -72,6 +72,7 @@ object CommonDeclarationCheckers : DeclarationCheckers() {
             FirLocalVariableTypeParametersSyntaxChecker,
             FirDelegateUsesExtensionPropertyTypeParameterChecker,
             FirTopLevelPropertiesChecker,
+            FirLocalExtensionPropertyChecker,
         )
 
     override val backingFieldCheckers: Set<FirBackingFieldChecker>

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

@@ -0,0 +1,21 @@
+/*
+ * Copyright 2010-2023 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.diagnostics.DiagnosticReporter
+import org.jetbrains.kotlin.diagnostics.reportOn
+import org.jetbrains.kotlin.fir.analysis.checkers.context.CheckerContext
+import org.jetbrains.kotlin.fir.analysis.diagnostics.FirErrors
+import org.jetbrains.kotlin.fir.declarations.FirProperty
+import org.jetbrains.kotlin.fir.declarations.utils.isExtension
+
+object FirLocalExtensionPropertyChecker : FirPropertyChecker() {
+    override fun check(declaration: FirProperty, context: CheckerContext, reporter: DiagnosticReporter) {
+        if (declaration.isLocal && declaration.isExtension) {
+            reporter.reportOn(declaration.receiverParameter?.source, FirErrors.LOCAL_EXTENSION_PROPERTY, context)
+        }
+    }
+}

compiler/fir/checkers/src/org/jetbrains/kotlin/fir/analysis/diagnostics/FirErrorsDefaultMessages.kt

@@ -300,6 +300,7 @@ import org.jetbrains.kotlin.fir.analysis.diagnostics.FirErrors.LATEINIT_NULLABLE
 import org.jetbrains.kotlin.fir.analysis.diagnostics.FirErrors.LATEINIT_PROPERTY_FIELD_DECLARATION_WITH_INITIALIZER
 import org.jetbrains.kotlin.fir.analysis.diagnostics.FirErrors.LEAKED_IN_PLACE_LAMBDA
 import org.jetbrains.kotlin.fir.analysis.diagnostics.FirErrors.LOCAL_ANNOTATION_CLASS_ERROR
+import org.jetbrains.kotlin.fir.analysis.diagnostics.FirErrors.LOCAL_EXTENSION_PROPERTY
 import org.jetbrains.kotlin.fir.analysis.diagnostics.FirErrors.LOCAL_INTERFACE_NOT_ALLOWED
 import org.jetbrains.kotlin.fir.analysis.diagnostics.FirErrors.LOCAL_OBJECT_NOT_ALLOWED
 import org.jetbrains.kotlin.fir.analysis.diagnostics.FirErrors.LOCAL_VARIABLE_WITH_TYPE_PARAMETERS
@@ -1668,6 +1669,8 @@ object FirErrorsDefaultMessages : BaseDiagnosticRendererFactory() {
         map.put(LATEINIT_INTRINSIC_CALL_IN_INLINE_FUNCTION, "This declaration can not be used inside an inline function")
         map.put(LATEINIT_INTRINSIC_CALL_ON_NON_ACCESSIBLE_PROPERTY, "Backing field of ''{0}'' is not accessible at this point", SYMBOL)
 
+        map.put(LOCAL_EXTENSION_PROPERTY, "Local extension properties are not allowed")
+
         map.put(CONST_VAL_NOT_TOP_LEVEL_OR_OBJECT, "Const 'val' are only allowed on top level, in named objects, or in companion objects")
         map.put(CONST_VAL_WITH_GETTER, "Const 'val' should not have a getter")
         map.put(CONST_VAL_WITH_DELEGATE, "Const 'val' should not have a delegate")