IrTypes: IrFunction.returnType can depend on type parameters

Function return type can depend on function type parameters and should
be initialized with type parameters in scope.

compiler/ir/ir.psi2ir/src/org/jetbrains/kotlin/psi2ir/generators/ClassGenerator.kt

@@ -207,10 +207,13 @@ class ClassGenerator(
         context.symbolTable.declareSimpleFunctionWithOverrides(
             irDelegate.startOffset, irDelegate.endOffset,
             IrDeclarationOrigin.DELEGATED_MEMBER,
-            delegated,
-            delegated.returnType!!.toIrType()
+            delegated
         ).buildWithScope { irFunction ->
             FunctionGenerator(declarationGenerator).generateSyntheticFunctionParameterDeclarations(irFunction)
+
+            // TODO could possibly refer to scoped type parameters for property accessors
+            irFunction.returnType = delegated.returnType!!.toIrType()
+
             irFunction.body = generateDelegateFunctionBody(irDelegate, delegated, overridden, irFunction)
         }
 

compiler/ir/ir.psi2ir/src/org/jetbrains/kotlin/psi2ir/generators/DataClassMembersGenerator.kt

@@ -55,8 +55,10 @@ class DataClassMembersGenerator(
     private fun declareSimpleFunction(startOffset: Int, endOffset: Int, origin: IrDeclarationOrigin, function: FunctionDescriptor) =
         context.symbolTable.declareSimpleFunctionWithOverrides(
             startOffset, endOffset, origin,
-            function, function.returnType!!.toIrType()
-        )
+            function
+        ).apply {
+            returnType = function.returnType!!.toIrType()
+        }
 
     private inner class MemberFunctionBuilder(
         val irClass: IrClass,

compiler/ir/ir.psi2ir/src/org/jetbrains/kotlin/psi2ir/generators/DelegatedPropertyGenerator.kt

@@ -100,9 +100,9 @@ class DelegatedPropertyGenerator(declarationGenerator: DeclarationGenerator) : D
         context.symbolTable.declareSimpleFunctionWithOverrides(
             ktDelegate.startOffset, ktDelegate.endOffset,
             IrDeclarationOrigin.DELEGATED_PROPERTY_ACCESSOR,
-            accessorDescriptor, accessorDescriptor.returnType!!.toIrType()
+            accessorDescriptor
         ).buildWithScope { irAccessor ->
-            FunctionGenerator(declarationGenerator).generateFunctionParameterDeclarations(irAccessor, ktProperty, null)
+            FunctionGenerator(declarationGenerator).generateFunctionParameterDeclarationsAndReturnType(irAccessor, ktProperty, null)
             irAccessor.body = generateBody(irAccessor)
         }
 
@@ -338,9 +338,9 @@ class DelegatedPropertyGenerator(declarationGenerator: DeclarationGenerator) : D
         context.symbolTable.declareSimpleFunctionWithOverrides(
             ktDelegate.startOffset, ktDelegate.endOffset,
             IrDeclarationOrigin.DELEGATED_PROPERTY_ACCESSOR,
-            getterDescriptor, getterDescriptor.returnType!!.toIrType()
+            getterDescriptor
         ).buildWithScope { irAccessor ->
-            FunctionGenerator(declarationGenerator).generateFunctionParameterDeclarations(irAccessor, ktDelegate, null)
+            FunctionGenerator(declarationGenerator).generateFunctionParameterDeclarationsAndReturnType(irAccessor, ktDelegate, null)
             irAccessor.body = generateBody(irAccessor)
         }
 

compiler/ir/ir.psi2ir/src/org/jetbrains/kotlin/psi2ir/generators/EnumClassMembersGenerator.kt

@@ -42,9 +42,9 @@ class EnumClassMembersGenerator(declarationGenerator: DeclarationGenerator) : De
             context.symbolTable.declareSimpleFunctionWithOverrides(
                 irClass.startOffset, irClass.endOffset,
                 IrDeclarationOrigin.ENUM_CLASS_SPECIAL_MEMBER,
-                valuesFunction, valuesFunction.returnType!!.toIrType()
+                valuesFunction
             ).also { irFunction ->
-                FunctionGenerator(declarationGenerator).generateFunctionParameterDeclarations(irFunction, null, null)
+                FunctionGenerator(declarationGenerator).generateFunctionParameterDeclarationsAndReturnType(irFunction, null, null)
                 irFunction.body = IrSyntheticBodyImpl(irClass.startOffset, irClass.endOffset, IrSyntheticBodyKind.ENUM_VALUES)
             }
         )
@@ -61,9 +61,9 @@ class EnumClassMembersGenerator(declarationGenerator: DeclarationGenerator) : De
             context.symbolTable.declareSimpleFunctionWithOverrides(
                 UNDEFINED_OFFSET, UNDEFINED_OFFSET,
                 IrDeclarationOrigin.ENUM_CLASS_SPECIAL_MEMBER,
-                valueOfFunction, valueOfFunction.returnType!!.toIrType()
+                valueOfFunction
             ).also { irFunction ->
-                FunctionGenerator(declarationGenerator).generateFunctionParameterDeclarations(irFunction, null, null)
+                FunctionGenerator(declarationGenerator).generateFunctionParameterDeclarationsAndReturnType(irFunction, null, null)
                 irFunction.body = IrSyntheticBodyImpl(irClass.startOffset, irClass.endOffset, IrSyntheticBodyKind.ENUM_VALUEOF)
             }
         )

compiler/ir/ir.psi2ir/src/org/jetbrains/kotlin/psi2ir/generators/FunctionGenerator.kt

@@ -59,7 +59,7 @@ class FunctionGenerator(declarationGenerator: DeclarationGenerator) : Declaratio
 
     fun generateFakeOverrideFunction(functionDescriptor: FunctionDescriptor, ktElement: KtElement): IrSimpleFunction =
         declareSimpleFunctionInner(functionDescriptor, ktElement, IrDeclarationOrigin.FAKE_OVERRIDE).buildWithScope { irFunction ->
-            generateFunctionParameterDeclarations(irFunction, ktElement, null)
+            generateFunctionParameterDeclarationsAndReturnType(irFunction, ktElement, null)
         }
 
     private inline fun declareSimpleFunction(
@@ -70,7 +70,7 @@ class FunctionGenerator(declarationGenerator: DeclarationGenerator) : Declaratio
         generateBody: BodyGenerator.() -> IrBody?
     ): IrSimpleFunction =
         declareSimpleFunctionInner(descriptor, ktFunction, origin).buildWithScope { irFunction ->
-            generateFunctionParameterDeclarations(irFunction, ktFunction, ktReceiver)
+            generateFunctionParameterDeclarationsAndReturnType(irFunction, ktFunction, ktReceiver)
             irFunction.body = createBodyGenerator(irFunction.symbol).generateBody()
         }
 
@@ -81,15 +81,16 @@ class FunctionGenerator(declarationGenerator: DeclarationGenerator) : Declaratio
     ): IrSimpleFunction =
         context.symbolTable.declareSimpleFunctionWithOverrides(
             ktElement.startOffset, ktElement.endOffset, origin,
-            descriptor, descriptor.returnType!!.toIrType()
+            descriptor
         )
 
-    fun generateFunctionParameterDeclarations(
+    fun generateFunctionParameterDeclarationsAndReturnType(
         irFunction: IrFunction,
         ktParameterOwner: KtElement?,
         ktReceiverParameterElement: KtElement?
     ) {
         declarationGenerator.generateScopedTypeParameterDeclarations(irFunction, irFunction.descriptor.typeParameters)
+        irFunction.returnType = irFunction.descriptor.returnType!!.toIrType()
         generateValueParameterDeclarations(irFunction, ktParameterOwner, ktReceiverParameterElement)
     }
 
@@ -104,7 +105,7 @@ class FunctionGenerator(declarationGenerator: DeclarationGenerator) : Declaratio
             if (ktAccessor != null) IrDeclarationOrigin.DEFINED else IrDeclarationOrigin.DEFAULT_PROPERTY_ACCESSOR
         ).buildWithScope { irAccessor ->
             declarationGenerator.generateScopedTypeParameterDeclarations(irAccessor, descriptor.correspondingProperty.typeParameters)
-            generateFunctionParameterDeclarations(irAccessor, ktAccessor ?: ktProperty, ktProperty.receiverTypeReference)
+            generateFunctionParameterDeclarationsAndReturnType(irAccessor, ktAccessor ?: ktProperty, ktProperty.receiverTypeReference)
             val ktBodyExpression = ktAccessor?.bodyExpression
             irAccessor.body =
                     if (ktBodyExpression != null)
@@ -236,10 +237,11 @@ class FunctionGenerator(declarationGenerator: DeclarationGenerator) : Declaratio
     ): IrConstructor =
         context.symbolTable.declareConstructor(
             ktConstructorElement.startOffset, ktConstructorElement.endOffset, IrDeclarationOrigin.DEFINED,
-            constructorDescriptor, constructorDescriptor.returnType.toIrType()
+            constructorDescriptor
         ).buildWithScope { irConstructor ->
             generateValueParameterDeclarations(irConstructor, ktParametersElement, null)
             irConstructor.body = createBodyGenerator(irConstructor.symbol).generateBody()
+            irConstructor.returnType = constructorDescriptor.returnType.toIrType()
         }
 
     fun generateSyntheticFunctionParameterDeclarations(irFunction: IrFunction) {