FIR: add a resolution mode for property delegates

Like function arguments, they are context-dependent, but unlike function
arguments, callable references should be resolved eagerly as if they are
explicit receivers.

compiler/fir/fir2ir/src/org/jetbrains/kotlin/fir/backend/generators/CallAndReferenceGenerator.kt

@@ -6,12 +6,12 @@
 package org.jetbrains.kotlin.fir.backend.generators
 
 import org.jetbrains.kotlin.descriptors.Visibilities
+import org.jetbrains.kotlin.fir.FirFakeSourceElementKind
 import org.jetbrains.kotlin.fir.backend.*
 import org.jetbrains.kotlin.fir.declarations.*
 import org.jetbrains.kotlin.fir.dispatchReceiverClassOrNull
 import org.jetbrains.kotlin.fir.expressions.*
 import org.jetbrains.kotlin.fir.expressions.impl.FirNoReceiverExpression
-import org.jetbrains.kotlin.fir.psi
 import org.jetbrains.kotlin.fir.references.FirDelegateFieldReference
 import org.jetbrains.kotlin.fir.references.FirReference
 import org.jetbrains.kotlin.fir.references.FirResolvedNamedReference
@@ -35,7 +35,6 @@ import org.jetbrains.kotlin.ir.expressions.impl.*
 import org.jetbrains.kotlin.ir.symbols.*
 import org.jetbrains.kotlin.ir.types.*
 import org.jetbrains.kotlin.ir.util.*
-import org.jetbrains.kotlin.psi.KtPropertyDelegate
 import org.jetbrains.kotlin.psi2ir.generators.hasNoSideEffects
 import org.jetbrains.kotlin.types.AbstractTypeApproximator
 
@@ -59,11 +58,12 @@ class CallAndReferenceGenerator(
         val symbol =
             callableReferenceAccess.calleeReference.toSymbolForCall(session, classifierStorage, declarationStorage, conversionScope)
         val type = callableReferenceAccess.typeRef.toIrType()
-        fun propertyOrigin(): IrStatementOrigin? =
+        // val x by y ->
-            when (callableReferenceAccess.source?.psi?.parent) {
+        //   val `x$delegate` = y
-                is KtPropertyDelegate -> IrStatementOrigin.PROPERTY_REFERENCE_FOR_DELEGATE
+        //   val x get() = `x$delegate`.getValue(this, ::x)
-                else -> null
+        // The reference here (like the rest of the accessor) has DefaultAccessor source kind.
-            }
+        val isForDelegate = callableReferenceAccess.source?.kind == FirFakeSourceElementKind.DefaultAccessor
+        val origin = if (isForDelegate) IrStatementOrigin.PROPERTY_REFERENCE_FOR_DELEGATE else null
         return callableReferenceAccess.convertWithOffsets { startOffset, endOffset ->
             when (symbol) {
                 is IrPropertySymbol -> {
@@ -82,7 +82,7 @@ class CallAndReferenceGenerator(
                         field = backingFieldSymbol,
                         getter = referencedPropertyGetter?.symbol,
                         setter = referencedPropertySetterSymbol,
-                        propertyOrigin()
+                        origin = origin
                     )
                 }
                 is IrLocalDelegatedPropertySymbol -> {
@@ -91,7 +91,7 @@ class CallAndReferenceGenerator(
                         delegate = symbol.owner.delegate.symbol,
                         getter = symbol.owner.getter.symbol,
                         setter = symbol.owner.setter?.symbol,
-                        IrStatementOrigin.PROPERTY_REFERENCE_FOR_DELEGATE
+                        origin = origin
                     )
                 }
                 is IrFieldSymbol -> {
@@ -111,7 +111,7 @@ class CallAndReferenceGenerator(
                         field = symbol,
                         getter = if (referencedField.isStatic) null else propertySymbol.owner.getter?.symbol,
                         setter = if (referencedField.isStatic) null else propertySymbol.owner.setter?.symbol,
-                        propertyOrigin()
+                        origin
                     )
                 }
                 is IrConstructorSymbol -> {

compiler/fir/fir2ir/tests/org/jetbrains/kotlin/codegen/ir/FirBlackBoxCodegenTestGenerated.java

@@ -10028,6 +10028,11 @@ public class FirBlackBoxCodegenTestGenerated extends AbstractFirBlackBoxCodegenT
             runTest("compiler/testData/codegen/box/delegatedProperty/delegateForExtPropertyInClass.kt");
         }
 
+        @TestMetadata("delegateToAnother.kt")
+        public void testDelegateToAnother() throws Exception {
+            runTest("compiler/testData/codegen/box/delegatedProperty/delegateToAnother.kt");
+        }
+
         @TestMetadata("delegateWithPrivateSet.kt")
         public void testDelegateWithPrivateSet() throws Exception {
             runTest("compiler/testData/codegen/box/delegatedProperty/delegateWithPrivateSet.kt");

compiler/fir/raw-fir/raw-fir.common/src/org/jetbrains/kotlin/fir/builder/ConversionUtils.kt

@@ -292,6 +292,7 @@ fun FirPropertyBuilder.generateAccessorsByDelegate(
         else -> null
     }
     val isMember = ownerSymbol != null
+    val fakeSource = delegateBuilder.source?.fakeElement(FirFakeSourceElementKind.DefaultAccessor)
 
     /*
      * If we have delegation with provide delegate then we generate call like
@@ -310,7 +311,7 @@ fun FirPropertyBuilder.generateAccessorsByDelegate(
     fun thisRef(isForDelegateProviderCall: Boolean = false): FirExpression =
         when {
             ownerSymbol != null -> buildThisReceiverExpression {
-                source = delegateBuilder.source
+                source = fakeSource
                 calleeReference = buildImplicitThisReference {
                     boundSymbol = ownerSymbol
                 }
@@ -320,7 +321,7 @@ fun FirPropertyBuilder.generateAccessorsByDelegate(
                 }
             }
             isExtension && !isForDelegateProviderCall -> buildThisReceiverExpression {
-                source = delegateBuilder.source
+                source = fakeSource
                 calleeReference = buildImplicitThisReference {
                     boundSymbol = this@generateAccessorsByDelegate.symbol
                 }
@@ -329,7 +330,7 @@ fun FirPropertyBuilder.generateAccessorsByDelegate(
         }
 
     fun delegateAccess() = buildQualifiedAccessExpression {
-        source = delegateBuilder.source
+        source = fakeSource
         calleeReference = buildDelegateFieldReference {
             resolvedSymbol = delegateFieldSymbol
         }
@@ -340,9 +341,9 @@ fun FirPropertyBuilder.generateAccessorsByDelegate(
 
     val isVar = this@generateAccessorsByDelegate.isVar
     fun propertyRef() = buildCallableReferenceAccess {
-        source = delegateBuilder.source
+        source = fakeSource
         calleeReference = buildResolvedNamedReference {
-            source = delegateBuilder.source
+            source = fakeSource
             name = this@generateAccessorsByDelegate.name
             resolvedSymbol = this@generateAccessorsByDelegate.symbol
         }
@@ -368,7 +369,7 @@ fun FirPropertyBuilder.generateAccessorsByDelegate(
     delegateBuilder.delegateProvider = if (stubMode) buildExpressionStub() else buildFunctionCall {
         explicitReceiver = receiver
         calleeReference = buildSimpleNamedReference {
-            source = delegateBuilder.source
+            source = fakeSource
             name = PROVIDE_DELEGATE
         }
         argumentList = buildBinaryArgumentList(thisRef(isForDelegateProviderCall = true), propertyRef())
@@ -379,7 +380,7 @@ fun FirPropertyBuilder.generateAccessorsByDelegate(
         val annotations = getter?.annotations
         val returnTarget = FirFunctionTarget(null, isLambda = false)
         getter = buildPropertyAccessor {
-            this.source = delegateBuilder.source
+            this.source = fakeSource
             this.session = session
             origin = FirDeclarationOrigin.Source
             returnTypeRef = buildImplicitTypeRef()
@@ -390,10 +391,10 @@ fun FirPropertyBuilder.generateAccessorsByDelegate(
             body = FirSingleExpressionBlock(
                 buildReturnExpression {
                     result = buildFunctionCall {
-                        source = delegateBuilder.source
+                        source = fakeSource
                         explicitReceiver = delegateAccess()
                         calleeReference = buildSimpleNamedReference {
-                            source = delegateBuilder.source
+                            source = fakeSource
                             name = GET_VALUE
                         }
                         argumentList = buildBinaryArgumentList(thisRef(), propertyRef())
@@ -411,14 +412,14 @@ fun FirPropertyBuilder.generateAccessorsByDelegate(
     if (isVar && (setter == null || setter is FirDefaultPropertyAccessor)) {
         val annotations = setter?.annotations
         setter = buildPropertyAccessor {
-            this.source = delegateBuilder.source
+            this.source = fakeSource
             this.session = session
             origin = FirDeclarationOrigin.Source
             returnTypeRef = session.builtinTypes.unitType
             isGetter = false
             status = FirDeclarationStatusImpl(Visibilities.Unknown, Modality.FINAL)
             val parameter = buildValueParameter {
-                source = delegateBuilder.source
+                source = fakeSource
                 this.session = session
                 origin = FirDeclarationOrigin.Source
                 returnTypeRef = buildImplicitTypeRef()
@@ -432,7 +433,7 @@ fun FirPropertyBuilder.generateAccessorsByDelegate(
             symbol = FirPropertyAccessorSymbol()
             body = FirSingleExpressionBlock(
                 buildFunctionCall {
-                    source = delegateBuilder.source
+                    source = fakeSource
                     explicitReceiver = delegateAccess()
                     calleeReference = buildSimpleNamedReference {
                         name = SET_VALUE
@@ -442,7 +443,7 @@ fun FirPropertyBuilder.generateAccessorsByDelegate(
                         arguments += propertyRef()
                         arguments += buildQualifiedAccessExpression {
                             calleeReference = buildResolvedNamedReference {
-                                source = delegateBuilder.source
+                                source = fakeSource
                                 name = DELEGATED_SETTER_PARAM
                                 resolvedSymbol = parameter.symbol
                             }

compiler/fir/resolve/src/org/jetbrains/kotlin/fir/resolve/ResolutionMode.kt

@@ -13,6 +13,7 @@ import org.jetbrains.kotlin.fir.types.builder.buildResolvedTypeRef
 
 sealed class ResolutionMode {
     object ContextDependent : ResolutionMode()
+    object ContextDependentDelegate : ResolutionMode()
     object ContextIndependent : ResolutionMode()
     // TODO: it's better not to use WithExpectedType(FirImplicitTypeRef)
     class WithExpectedType(val expectedTypeRef: FirTypeRef) : ResolutionMode()

compiler/fir/resolve/src/org/jetbrains/kotlin/fir/resolve/transformers/body/resolve/FirDeclarationsResolveTransformer.kt

@@ -192,7 +192,7 @@ open class FirDeclarationsResolveTransformer(transformer: FirBodyResolveTransfor
     }
 
     private fun transformPropertyWithDelegate(property: FirProperty) {
-        property.transformDelegate(transformer, ResolutionMode.ContextDependent)
+        property.transformDelegate(transformer, ResolutionMode.ContextDependentDelegate)
 
         val delegateExpression = property.delegate!!
 
@@ -230,7 +230,7 @@ open class FirDeclarationsResolveTransformer(transformer: FirBodyResolveTransfor
     ): CompositeTransformResult<FirStatement> {
         dataFlowAnalyzer.enterDelegateExpression()
         try {
-            val delegateProvider = wrappedDelegateExpression.delegateProvider.transformSingle(transformer, ResolutionMode.ContextDependent)
+            val delegateProvider = wrappedDelegateExpression.delegateProvider.transformSingle(transformer, data)
             when (val calleeReference = (delegateProvider as FirResolvable).calleeReference) {
                 is FirResolvedNamedReference -> return delegateProvider.compose()
                 is FirNamedReferenceWithCandidate -> {
@@ -243,7 +243,7 @@ open class FirDeclarationsResolveTransformer(transformer: FirBodyResolveTransfor
 
             (delegateProvider as? FirFunctionCall)?.let { dataFlowAnalyzer.dropSubgraphFromCall(it) }
             return wrappedDelegateExpression.expression
-                .transformSingle(transformer, ResolutionMode.ContextDependent)
+                .transformSingle(transformer, data)
                 .approximateIfIsIntegerConst()
                 .compose()
         } finally {
@@ -669,7 +669,7 @@ open class FirDeclarationsResolveTransformer(transformer: FirBodyResolveTransfor
             context.saveContextForAnonymousFunction(anonymousFunction)
         }
         return when (data) {
-            ResolutionMode.ContextDependent -> {
+            is ResolutionMode.ContextDependent, is ResolutionMode.ContextDependentDelegate -> {
                 dataFlowAnalyzer.visitPostponedAnonymousFunction(anonymousFunction)
                 anonymousFunction.addReturn().compose()
             }

compiler/fir/resolve/src/org/jetbrains/kotlin/fir/resolve/transformers/body/resolve/FirExpressionsResolveTransformer.kt

@@ -33,7 +33,6 @@ import org.jetbrains.kotlin.fir.symbols.impl.FirVariableSymbol
 import org.jetbrains.kotlin.fir.types.*
 import org.jetbrains.kotlin.fir.types.builder.*
 import org.jetbrains.kotlin.fir.visitors.*
-import org.jetbrains.kotlin.name.ClassId
 import org.jetbrains.kotlin.name.Name
 import org.jetbrains.kotlin.resolve.calls.tower.CandidateApplicability
 import org.jetbrains.kotlin.types.TypeApproximatorConfiguration
@@ -612,7 +611,7 @@ open class FirExpressionsResolveTransformer(transformer: FirBodyResolveTransform
             else
                 callableReferenceAccess
 
-        if (data !is ResolutionMode.ContextDependent) {
+        if (data !is ResolutionMode.ContextDependent /* ContextDependentDelegate is Ok here */) {
             val resolvedReference =
                 components.syntheticCallGenerator.resolveCallableReferenceWithSyntheticOuterCall(
                     callableReferenceAccess, data.expectedType, resolutionContext,

compiler/testData/codegen/box/delegatedProperty/delegateToAnother.kt

@@ -0,0 +1,9 @@
+// WITH_REFLECT
+// WITH_RUNTIME
+class C(val x: String)
+
+val x = "O"
+val y by ::x
+val z by C("K")::x
+
+fun box(): String = y + z

compiler/testData/diagnostics/tests/delegatedProperty/provideDelegate/provideDelegateOnFunctionalTypeWithThis.fir.fail

@@ -1,2 +0,0 @@
-Failures detected in FirBodyResolveTransformerAdapter, file: /provideDelegateOnFunctionalTypeWithThis.fir.kt
-Cause: java.lang.ClassCastException: org.jetbrains.kotlin.fir.types.impl.FirImplicitTypeRefImpl cannot be cast to org.jetbrains.kotlin.fir.types.FirResolvedTypeRef

compiler/testData/diagnostics/tests/delegatedProperty/provideDelegate/provideDelegateOnFunctionalTypeWithThis.fir.kt

@@ -13,7 +13,7 @@ fun wrong(arg: Wrong) {}
 class Wrong
 
 class Right {
-    val prop: () -> Unit by <!DELEGATE_SPECIAL_FUNCTION_MISSING, DELEGATE_SPECIAL_FUNCTION_NONE_APPLICABLE!>::wrong<!>
+    val prop: () -> Unit by <!UNRESOLVED_REFERENCE!>::wrong<!>
 }
 
 fun box(): String {

compiler/tests/org/jetbrains/kotlin/codegen/BlackBoxCodegenTestGenerated.java

@@ -11428,6 +11428,11 @@ public class BlackBoxCodegenTestGenerated extends AbstractBlackBoxCodegenTest {
             runTest("compiler/testData/codegen/box/delegatedProperty/delegateForExtPropertyInClass.kt");
         }
 
+        @TestMetadata("delegateToAnother.kt")
+        public void testDelegateToAnother() throws Exception {
+            runTest("compiler/testData/codegen/box/delegatedProperty/delegateToAnother.kt");
+        }
+
         @TestMetadata("delegateWithPrivateSet.kt")
         public void testDelegateWithPrivateSet() throws Exception {
             runTest("compiler/testData/codegen/box/delegatedProperty/delegateWithPrivateSet.kt");

compiler/tests/org/jetbrains/kotlin/codegen/LightAnalysisModeTestGenerated.java

@@ -11433,6 +11433,11 @@ public class LightAnalysisModeTestGenerated extends AbstractLightAnalysisModeTes
             runTest("compiler/testData/codegen/box/delegatedProperty/delegateForExtPropertyInClass.kt");
         }
 
+        @TestMetadata("delegateToAnother.kt")
+        public void testDelegateToAnother() throws Exception {
+            runTest("compiler/testData/codegen/box/delegatedProperty/delegateToAnother.kt");
+        }
+
         @TestMetadata("delegateWithPrivateSet.kt")
         public void testDelegateWithPrivateSet() throws Exception {
             runTest("compiler/testData/codegen/box/delegatedProperty/delegateWithPrivateSet.kt");

compiler/tests/org/jetbrains/kotlin/codegen/ir/IrBlackBoxCodegenTestGenerated.java

@@ -10028,6 +10028,11 @@ public class IrBlackBoxCodegenTestGenerated extends AbstractIrBlackBoxCodegenTes
             runTest("compiler/testData/codegen/box/delegatedProperty/delegateForExtPropertyInClass.kt");
         }
 
+        @TestMetadata("delegateToAnother.kt")
+        public void testDelegateToAnother() throws Exception {
+            runTest("compiler/testData/codegen/box/delegatedProperty/delegateToAnother.kt");
+        }
+
         @TestMetadata("delegateWithPrivateSet.kt")
         public void testDelegateWithPrivateSet() throws Exception {
             runTest("compiler/testData/codegen/box/delegatedProperty/delegateWithPrivateSet.kt");

js/js.tests/test/org/jetbrains/kotlin/js/test/es6/semantics/IrJsCodegenBoxES6TestGenerated.java

@@ -8543,6 +8543,11 @@ public class IrJsCodegenBoxES6TestGenerated extends AbstractIrJsCodegenBoxES6Tes
             runTest("compiler/testData/codegen/box/delegatedProperty/delegateForExtPropertyInClass.kt");
         }
 
+        @TestMetadata("delegateToAnother.kt")
+        public void testDelegateToAnother() throws Exception {
+            runTest("compiler/testData/codegen/box/delegatedProperty/delegateToAnother.kt");
+        }
+
         @TestMetadata("delegateWithPrivateSet.kt")
         public void testDelegateWithPrivateSet() throws Exception {
             runTest("compiler/testData/codegen/box/delegatedProperty/delegateWithPrivateSet.kt");

js/js.tests/test/org/jetbrains/kotlin/js/test/ir/semantics/IrJsCodegenBoxTestGenerated.java

@@ -8543,6 +8543,11 @@ public class IrJsCodegenBoxTestGenerated extends AbstractIrJsCodegenBoxTest {
             runTest("compiler/testData/codegen/box/delegatedProperty/delegateForExtPropertyInClass.kt");
         }
 
+        @TestMetadata("delegateToAnother.kt")
+        public void testDelegateToAnother() throws Exception {
+            runTest("compiler/testData/codegen/box/delegatedProperty/delegateToAnother.kt");
+        }
+
         @TestMetadata("delegateWithPrivateSet.kt")
         public void testDelegateWithPrivateSet() throws Exception {
             runTest("compiler/testData/codegen/box/delegatedProperty/delegateWithPrivateSet.kt");

js/js.tests/test/org/jetbrains/kotlin/js/test/semantics/JsCodegenBoxTestGenerated.java

@@ -8543,6 +8543,11 @@ public class JsCodegenBoxTestGenerated extends AbstractJsCodegenBoxTest {
             runTest("compiler/testData/codegen/box/delegatedProperty/delegateForExtPropertyInClass.kt");
         }
 
+        @TestMetadata("delegateToAnother.kt")
+        public void testDelegateToAnother() throws Exception {
+            runTest("compiler/testData/codegen/box/delegatedProperty/delegateToAnother.kt");
+        }
+
         @TestMetadata("delegateWithPrivateSet.kt")
         public void testDelegateWithPrivateSet() throws Exception {
             runTest("compiler/testData/codegen/box/delegatedProperty/delegateWithPrivateSet.kt");