[FIR] Don't report DEPRECATION on self-access in delegated property

#KT-60682

compiler/fir/checkers/src/org/jetbrains/kotlin/fir/analysis/checkers/expression/FirDeprecationChecker.kt

@@ -6,7 +6,6 @@
 package org.jetbrains.kotlin.fir.analysis.checkers.expression
 
 import org.jetbrains.kotlin.KtFakeSourceElementKind
-import org.jetbrains.kotlin.KtRealSourceElementKind
 import org.jetbrains.kotlin.KtSourceElement
 import org.jetbrains.kotlin.config.KotlinCompilerVersion
 import org.jetbrains.kotlin.diagnostics.DiagnosticReporter
@@ -29,6 +28,7 @@ import org.jetbrains.kotlin.fir.references.resolved
 import org.jetbrains.kotlin.fir.resolve.firClassLike
 import org.jetbrains.kotlin.fir.resolve.typeAliasForConstructor
 import org.jetbrains.kotlin.fir.symbols.FirBasedSymbol
+import org.jetbrains.kotlin.fir.symbols.SymbolInternals
 import org.jetbrains.kotlin.fir.symbols.impl.FirClassLikeSymbol
 import org.jetbrains.kotlin.fir.symbols.impl.FirConstructorSymbol
 import org.jetbrains.kotlin.fir.symbols.impl.FirTypeAliasSymbol
@@ -51,6 +51,9 @@ object FirDeprecationChecker : FirBasicExpressionChecker() {
         val calleeReference = expression.calleeReference ?: return
         val resolvedReference = calleeReference.resolved ?: return
         val referencedSymbol = resolvedReference.resolvedSymbol
+
+        if (expression.isDelegatedPropertySelfAccess(context, referencedSymbol)) return
+
         val source = resolvedReference.source ?: expression.source
 
         if (expression is FirDelegatedConstructorCall) {
@@ -67,6 +70,19 @@ object FirDeprecationChecker : FirBasicExpressionChecker() {
         }
     }
 
+    /** Checks if this is an access to a delegated property inside the delegated property itself.
+     *  Deprecations shouldn't be reported here. */
+    @OptIn(SymbolInternals::class)
+    private fun FirStatement.isDelegatedPropertySelfAccess(context: CheckerContext, referencedSymbol: FirBasedSymbol<*>): Boolean {
+        if (source?.kind != KtFakeSourceElementKind.DelegatedPropertyAccessor) return false
+        val containers = context.containingDeclarations
+        val size = containers.size
+        val fir = referencedSymbol.fir
+
+        return containers.getOrNull(size - 1) == fir // For `provideDelegate`, the call will be in the initializer
+                || containers.getOrNull(size - 2) == fir // For `getValue`, the call will be in the accessor
+    }
+
     internal fun reportApiStatusIfNeeded(
         source: KtSourceElement?,
         referencedSymbol: FirBasedSymbol<*>,

compiler/testData/diagnostics/tests/deprecated/propertyUsage.fir.kt

@@ -13,6 +13,15 @@ class Delegate() {
     operator fun setValue(instance: Any, property: KProperty<*>, value: Int) {}
 }
 
+class Delegate2() {
+    operator fun getValue(instance: Any, property: KProperty<*>) : Int = 1
+    operator fun setValue(instance: Any, property: KProperty<*>, value: Int) {}
+}
+
+class DelegateProvider() {
+    operator fun provideDelegate(instance: Any, property: KProperty<*>) = Delegate2()
+}
+
 class PropertyHolder {
     @Deprecated("text")
     val x = 1
@@ -23,6 +32,14 @@ class PropertyHolder {
     val valDelegate by <!DEPRECATION!>Delegate<!>()
     var varDelegate by <!DEPRECATION, DEPRECATION!>Delegate<!>()
 
+    // no deprecation caused by access to itself
+    @Deprecated("text")
+    var deprecatedDelegated by Delegate2()
+
+    // no deprecation caused by access to itself
+    @Deprecated("text")
+    val deprecatedDelegated2 by DelegateProvider()
+
     public val test1: String = ""
         @Deprecated("val-getter") get
 

compiler/testData/diagnostics/tests/deprecated/propertyUsage.kt

@@ -13,6 +13,15 @@ class Delegate() {
     operator fun setValue(instance: Any, property: KProperty<*>, value: Int) {}
 }
 
+class Delegate2() {
+    operator fun getValue(instance: Any, property: KProperty<*>) : Int = 1
+    operator fun setValue(instance: Any, property: KProperty<*>, value: Int) {}
+}
+
+class DelegateProvider() {
+    operator fun provideDelegate(instance: Any, property: KProperty<*>) = Delegate2()
+}
+
 class PropertyHolder {
     @Deprecated("text")
     val x = 1
@@ -23,6 +32,14 @@ class PropertyHolder {
     val valDelegate by <!DEPRECATION!>Delegate()<!>
     var varDelegate by <!DEPRECATION, DEPRECATION!>Delegate()<!>
 
+    // no deprecation caused by access to itself
+    @Deprecated("text")
+    var deprecatedDelegated by Delegate2()
+
+    // no deprecation caused by access to itself
+    @Deprecated("text")
+    val deprecatedDelegated2 by DelegateProvider()
+
     public val test1: String = ""
         @Deprecated("val-getter") get
 

compiler/testData/diagnostics/tests/deprecated/propertyUsage.txt

@@ -13,8 +13,27 @@ public final class Delegate {
     public open override /*1*/ /*fake_override*/ fun toString(): kotlin.String
 }
 
+public final class Delegate2 {
+    public constructor Delegate2()
+    public open override /*1*/ /*fake_override*/ fun equals(/*0*/ other: kotlin.Any?): kotlin.Boolean
+    public final operator fun getValue(/*0*/ instance: kotlin.Any, /*1*/ property: kotlin.reflect.KProperty<*>): kotlin.Int
+    public open override /*1*/ /*fake_override*/ fun hashCode(): kotlin.Int
+    public final operator fun setValue(/*0*/ instance: kotlin.Any, /*1*/ property: kotlin.reflect.KProperty<*>, /*2*/ value: kotlin.Int): kotlin.Unit
+    public open override /*1*/ /*fake_override*/ fun toString(): kotlin.String
+}
+
+public final class DelegateProvider {
+    public constructor DelegateProvider()
+    public open override /*1*/ /*fake_override*/ fun equals(/*0*/ other: kotlin.Any?): kotlin.Boolean
+    public open override /*1*/ /*fake_override*/ fun hashCode(): kotlin.Int
+    public final operator fun provideDelegate(/*0*/ instance: kotlin.Any, /*1*/ property: kotlin.reflect.KProperty<*>): Delegate2
+    public open override /*1*/ /*fake_override*/ fun toString(): kotlin.String
+}
+
 public final class PropertyHolder {
     public constructor PropertyHolder()
+    @kotlin.Deprecated(message = "text") public final var deprecatedDelegated: kotlin.Int
+    @kotlin.Deprecated(message = "text") public final val deprecatedDelegated2: kotlin.Int
     @kotlin.Deprecated(message = "text") public final var name: kotlin.String
     @get:kotlin.Deprecated(message = "val-getter") public final val test1: kotlin.String = ""
     @get:kotlin.Deprecated(message = "var-getter") @set:kotlin.Deprecated(message = "var-setter") public final var test2: kotlin.String