[KAPT] Fix field type correction for delegates (#4107)

#KT-37586 Fixes

plugins/kapt3/kapt3-compiler/src/org/jetbrains/kotlin/kapt3/stubs/ClassFileToSourceStubConverter.kt

@@ -56,6 +56,7 @@ import org.jetbrains.kotlin.psi.*
 import org.jetbrains.kotlin.resolve.BindingContext
 import org.jetbrains.kotlin.resolve.DelegatingBindingTrace
 import org.jetbrains.kotlin.resolve.calls.callUtil.getResolvedCall
+import org.jetbrains.kotlin.resolve.calls.callUtil.getType
 import org.jetbrains.kotlin.resolve.calls.model.DefaultValueArgument
 import org.jetbrains.kotlin.resolve.calls.model.ResolvedValueArgument
 import org.jetbrains.kotlin.resolve.constants.*
@@ -704,20 +705,31 @@ class ClassFileToSourceStubConverter(val kaptContext: KaptContextForStubGenerati
             return null
         }
 
+        fun typeFromAsm() = signatureParser.parseFieldSignature(field.signature, treeMaker.Type(type))
+
         // Enum type must be an identifier (Javac requirement)
-        val typeExpression = if (isEnum(field.access))
+        val typeExpression = if (isEnum(field.access)) {
             treeMaker.SimpleName(treeMaker.getQualifiedName(type).substringAfterLast('.'))
-        else
+        } else if (descriptor is PropertyDescriptor && descriptor.isDelegated) {
             getNonErrorType(
-                (descriptor as? CallableDescriptor)?.returnType, RETURN_TYPE,
+                (origin.element as? KtProperty)?.delegateExpression?.getType(kaptContext.bindingContext),
+                RETURN_TYPE,
+                ktTypeProvider = { null },
+                ifNonError = ::typeFromAsm
+            )
+        } else {
+            getNonErrorType(
+                (descriptor as? CallableDescriptor)?.returnType,
+                RETURN_TYPE,
                 ktTypeProvider = {
                     val fieldOrigin = (kaptContext.origins[field]?.element as? KtCallableDeclaration)
                         ?.takeIf { it !is KtFunction }
 
                     fieldOrigin?.typeReference
                 },
-                ifNonError = { signatureParser.parseFieldSignature(field.signature, treeMaker.Type(type)) }
+                ifNonError = ::typeFromAsm
             )
+        }
 
         lineMappings.registerField(containingClass, field)
 

plugins/kapt3/kapt3-compiler/test/org/jetbrains/kotlin/kapt3/test/ClassFileToSourceStubConverterTestGenerated.java

@@ -119,6 +119,11 @@ public class ClassFileToSourceStubConverterTestGenerated extends AbstractClassFi
         runTest("plugins/kapt3/kapt3-compiler/testData/converter/defaultParameterValueOn.kt");
     }
 
+    @TestMetadata("delegateCorrectErrorTypes.kt")
+    public void testDelegateCorrectErrorTypes() throws Exception {
+        runTest("plugins/kapt3/kapt3-compiler/testData/converter/delegateCorrectErrorTypes.kt");
+    }
+
     @TestMetadata("deprecated.kt")
     public void testDeprecated() throws Exception {
         runTest("plugins/kapt3/kapt3-compiler/testData/converter/deprecated.kt");

plugins/kapt3/kapt3-compiler/test/org/jetbrains/kotlin/kapt3/test/IrClassFileToSourceStubConverterTestGenerated.java

@@ -120,6 +120,11 @@ public class IrClassFileToSourceStubConverterTestGenerated extends AbstractIrCla
         runTest("plugins/kapt3/kapt3-compiler/testData/converter/defaultParameterValueOn.kt");
     }
 
+    @TestMetadata("delegateCorrectErrorTypes.kt")
+    public void testDelegateCorrectErrorTypes() throws Exception {
+        runTest("plugins/kapt3/kapt3-compiler/testData/converter/delegateCorrectErrorTypes.kt");
+    }
+
     @TestMetadata("deprecated.kt")
     public void testDeprecated() throws Exception {
         runTest("plugins/kapt3/kapt3-compiler/testData/converter/deprecated.kt");

plugins/kapt3/kapt3-compiler/testData/converter/delegateCorrectErrorTypes.kt

@@ -0,0 +1,13 @@
+// CORRECT_ERROR_TYPES
+
+@file:Suppress("UNRESOLVED_REFERENCE")
+
+package test
+
+class Delegate {
+    operator fun getValue(thisRef: Any, property: KProperty<*>): Any {return Any()}
+}
+
+class Bar(delegate: Delegate) {
+    private val unknown: Unknown by delegate
+}

plugins/kapt3/kapt3-compiler/testData/converter/delegateCorrectErrorTypes.txt

@@ -0,0 +1,38 @@
+package test;
+
+import java.lang.System;
+
+@kotlin.Metadata()
+public final class Bar {
+    private final test.Delegate unknown$delegate = null;
+
+    public Bar(@org.jetbrains.annotations.NotNull()
+    test.Delegate delegate) {
+        super();
+    }
+
+    private final Unknown getUnknown() {
+        return null;
+    }
+}
+
+////////////////////
+
+package test;
+
+import java.lang.System;
+
+@kotlin.Metadata()
+public final class Delegate {
+
+    public Delegate() {
+        super();
+    }
+
+    @org.jetbrains.annotations.NotNull()
+    public final java.lang.Object getValue(@org.jetbrains.annotations.NotNull()
+    java.lang.Object thisRef, @org.jetbrains.annotations.NotNull()
+    KProperty<?> property) {
+        return null;
+    }
+}