[FIR] Add test data

compiler/fir/analysis-tests/testData/resolveWithStdlib/properties/backingField/backingFieldModifiers.fir.txt

@@ -0,0 +1,28 @@
+FILE: backingFieldModifiers.kt
+    public final class A : R|kotlin/Any| {
+        public constructor(): R|A| {
+            super<R|kotlin/Any|>()
+        }
+
+        public final val a: R|kotlin/Number|
+            public get(): R|kotlin/Number|
+
+        public final val b: R|kotlin/Number|
+            public get(): R|kotlin/Number|
+
+        public final val c: R|kotlin/Number|
+            public get(): R|kotlin/Number|
+
+        public final val d: R|kotlin/Number|
+            public get(): R|kotlin/Number|
+
+        public final val e: R|kotlin/Number|
+            public get(): R|kotlin/Number|
+
+        public final val f: R|kotlin/Number|
+            public get(): R|kotlin/Number|
+
+        public final val g: R|kotlin/Number|
+            public get(): R|kotlin/Number|
+
+    }

compiler/fir/analysis-tests/testData/resolveWithStdlib/properties/backingField/backingFieldModifiers.kt

@@ -0,0 +1,22 @@
+class A {
+    val a: Number
+        <!WRONG_MODIFIER_TARGET!>abstract<!> field = 1
+
+    val b: Number
+        <!WRONG_MODIFIER_TARGET!>open<!> field = 1
+
+    val c: Number
+        <!WRONG_MODIFIER_TARGET!>final<!> field = 1
+
+    val d: Number
+        <!WRONG_MODIFIER_TARGET!>inline<!> field = 1
+
+    val e: Number
+        <!WRONG_MODIFIER_TARGET!>noinline<!> field = 1
+
+    val f: Number
+        <!WRONG_MODIFIER_TARGET!>crossinline<!> field = 1
+
+    val g: Number
+        <!WRONG_MODIFIER_TARGET!>tailrec<!> field = 1
+}

compiler/fir/analysis-tests/testData/resolveWithStdlib/properties/backingField/backingFieldVisibility.fir.txt

@@ -0,0 +1,41 @@
+Module: lib
+FILE: A.kt
+    public final class A : R|kotlin/Any| {
+        public constructor(): R|A| {
+            super<R|kotlin/Any|>()
+        }
+
+        public final val a: R|kotlin/Number|
+            public get(): R|kotlin/Number|
+
+        public final val b: R|kotlin/Number|
+            public get(): R|kotlin/Number|
+
+        public final val c: R|kotlin/Number|
+            public get(): R|kotlin/Number|
+
+        public final val d: R|kotlin/Number|
+            public get(): R|kotlin/Number|
+
+        public final fun rest(): R|kotlin/Unit| {
+            lval aI: R|kotlin/Int| = R|/A.A|().R|/A.a|.R|kotlin/Int.plus|(Int(10))
+            lval bI: R|kotlin/Int| = R|/A.A|().R|/A.b|.R|kotlin/Int.plus|(Int(20))
+            lval cI: <ERROR TYPE REF: Unresolved name: plus> = R|/A.A|().R|/A.c|.<Unresolved name: plus>#(Int(30))
+            lval dI: <ERROR TYPE REF: Unresolved name: plus> = R|/A.A|().R|/A.d|.<Unresolved name: plus>#(Int(40))
+        }
+
+    }
+    public final fun test(): R|kotlin/Unit| {
+        lval aA: <ERROR TYPE REF: Unresolved name: plus> = R|/A.A|().R|/A.a|.<Unresolved name: plus>#(Int(10))
+        lval bA: R|kotlin/Int| = R|/A.A|().R|/A.b|.R|kotlin/Int.plus|(Int(20))
+        lval cA: <ERROR TYPE REF: Unresolved name: plus> = R|/A.A|().R|/A.c|.<Unresolved name: plus>#(Int(30))
+        lval dA: <ERROR TYPE REF: Unresolved name: plus> = R|/A.A|().R|/A.d|.<Unresolved name: plus>#(Int(40))
+    }
+Module: main
+FILE: B.kt
+    public final fun main(): R|kotlin/Unit| {
+        lval aB: <ERROR TYPE REF: Unresolved name: plus> = R|/A.A|().R|/A.a|.<Unresolved name: plus>#(Int(10))
+        lval bB: <ERROR TYPE REF: Unresolved name: plus> = R|/A.A|().R|/A.b|.<Unresolved name: plus>#(Int(20))
+        lval cB: <ERROR TYPE REF: Unresolved name: plus> = R|/A.A|().R|/A.c|.<Unresolved name: plus>#(Int(30))
+        lval dB: <ERROR TYPE REF: Unresolved name: plus> = R|/A.A|().R|/A.d|.<Unresolved name: plus>#(Int(40))
+    }

compiler/fir/analysis-tests/testData/resolveWithStdlib/properties/backingField/backingFieldVisibility.kt

@@ -0,0 +1,40 @@
+// MODULE: lib
+// FILE: A.kt
+
+class A {
+    val a: Number
+        private field = 1
+
+    val b: Number
+        internal field = 2
+
+    val c: Number
+        <!WRONG_MODIFIER_TARGET!>protected<!> field = 3
+
+    val d: Number
+        <!WRONG_MODIFIER_TARGET!>public<!> field = 5
+
+    fun rest() {
+        val aI = A().a + 10
+        val bI = A().b + 20
+        val cI = A().c <!UNRESOLVED_REFERENCE!>+<!> 30
+        val dI = A().d <!UNRESOLVED_REFERENCE!>+<!> 40
+    }
+}
+
+fun test() {
+    val aA = A().a <!UNRESOLVED_REFERENCE!>+<!> 10
+    val bA = A().b + 20
+    val cA = A().c <!UNRESOLVED_REFERENCE!>+<!> 30
+    val dA = A().d <!UNRESOLVED_REFERENCE!>+<!> 40
+}
+
+// MODULE: main(lib)
+// FILE: B.kt
+
+fun main() {
+    val aB = A().a <!UNRESOLVED_REFERENCE!>+<!> 10
+    val bB = A().b <!UNRESOLVED_REFERENCE!>+<!> 20
+    val cB = A().c <!UNRESOLVED_REFERENCE!>+<!> 30
+    val dB = A().d <!UNRESOLVED_REFERENCE!>+<!> 40
+}

compiler/fir/analysis-tests/testData/resolveWithStdlib/properties/backingField/backingFieldWithSmartTypeParameters.fir.txt

@@ -0,0 +1,6 @@
+FILE: backingFieldWithSmartTypeParameters.kt
+    public final val items: R|kotlin/collections/List<kotlin/String>|
+        public get(): R|kotlin/collections/List<kotlin/String>|
+    public final fun test(): R|kotlin/Unit| {
+        R|/items|.R|SubstitutionOverride<kotlin/collections/MutableList.add: R|kotlin/Boolean|>|(String(one more item))
+    }

compiler/fir/analysis-tests/testData/resolveWithStdlib/properties/backingField/backingFieldWithSmartTypeParameters.kt

@@ -0,0 +1,6 @@
+val items: List<String>
+    field = mutableListOf()
+
+fun test() {
+    items.add("one more item")
+}

compiler/fir/analysis-tests/testData/resolveWithStdlib/properties/backingField/explicitBackingFieldInInterface.fir.txt

@@ -0,0 +1,6 @@
+FILE: explicitBackingFieldInInterface.kt
+    public abstract interface I : R|kotlin/Any| {
+        public abstract val it: R|kotlin/Number|
+            public get(): R|kotlin/Number|
+
+    }

compiler/fir/analysis-tests/testData/resolveWithStdlib/properties/backingField/explicitBackingFieldInInterface.kt

@@ -0,0 +1,4 @@
+interface I {
+    val it: Number
+        <!EXPLICIT_BACKING_FIELD_IN_INTERFACE!>field<!> = 10
+}

compiler/fir/analysis-tests/testData/resolveWithStdlib/properties/backingField/explicitBackingFieldType.fir.txt

@@ -0,0 +1,49 @@
+FILE: explicitBackingFieldType.kt
+    public final class A : R|kotlin/Any| {
+        public constructor(): R|A| {
+            super<R|kotlin/Any|>()
+        }
+
+        public final val a: R|kotlin/Int| = Int(20)
+            public get(): R|kotlin/Int|
+
+        public final val it: R|kotlin/Number|
+            public get(): R|kotlin/Number|
+
+        public final val joke: R|kotlin/Number|
+            public get(): R|kotlin/Number|
+
+        public final val incompatible: R|kotlin/Number|
+            public get(): R|kotlin/Number|
+
+        public final val customGetterNeeded: R|kotlin/Int|
+            public get(): R|kotlin/Int|
+
+        public final val invertedTypes: R|kotlin/Int|
+            public get(): R|kotlin/Int| {
+                ^ Int(30)
+            }
+
+        public final val uninitialized: R|kotlin/Number|
+            public get(): R|kotlin/Number|
+
+        public final val uninitializedWithGetter: R|kotlin/Number|
+            public get(): R|kotlin/Number| {
+                ^ Int(2)
+            }
+
+        public final val initiaizedWithExplicitBackingField: R|kotlin/collections/List<kotlin/Int>| = R|kotlin/collections/listOf|<R|kotlin/Int|>(vararg(Int(1), Int(2)))
+            public get(): R|kotlin/collections/List<kotlin/Int>|
+
+        public final val p: R|kotlin/Int| = Int(5)
+            public get(): R|kotlin/Int| {
+                ^ this@R|/A|.F|/A.p|
+            }
+
+        public final var setterNeeded: R|kotlin/Int|
+            public get(): R|kotlin/Int| {
+                ^ this@R|/A|.F|/A.setterNeeded|.R|kotlin/String.length|
+            }
+            public set(value: R|kotlin/Int|): R|kotlin/Unit|
+
+    }

compiler/fir/analysis-tests/testData/resolveWithStdlib/properties/backingField/explicitBackingFieldType.kt

@@ -0,0 +1,36 @@
+class A {
+    val a = 20
+
+    val it: Number
+    field = 4
+
+    <!PROPERTY_MUST_HAVE_GETTER!>val joke: Number
+    field = "Haha"<!>
+
+    <!PROPERTY_MUST_HAVE_GETTER!>val incompatible: Number
+    field: Any? = 42<!>
+
+    <!PROPERTY_MUST_HAVE_GETTER!>val customGetterNeeded: Int
+    field: Number = 42<!>
+
+    val invertedTypes: Int
+    field: Number = 42
+    get() = 30
+
+    val uninitialized: Number
+    <!PROPERTY_FIELD_DECLARATION_MISSING_INITIALIZER!>field: Int<!>
+
+    val uninitializedWithGetter: Number
+    <!PROPERTY_FIELD_DECLARATION_MISSING_INITIALIZER!>field: Int<!>
+    get() = 2
+
+    val initiaizedWithExplicitBackingField = <!PROPERTY_INITIALIZER_WITH_EXPLICIT_FIELD_DECLARATION!>listOf(1, 2)<!>
+    <!PROPERTY_FIELD_DECLARATION_MISSING_INITIALIZER!>field: MutableList<Int><!>
+
+    val p = 5
+        get() = field
+
+    <!PROPERTY_MUST_HAVE_SETTER!>var setterNeeded: Int
+        field = "test"
+        get() = field.length<!>
+}

compiler/fir/analysis-tests/testData/resolveWithStdlib/properties/backingField/explicitBackingFieldsWithDelegates.fir.txt

@@ -0,0 +1,8 @@
+FILE: explicitBackingFieldsWithDelegates.kt
+    public final val thingWithDelefate: R|kotlin/Number|by R|kotlin/lazy|<R|kotlin/Number|>(<L> = lazy@fun <anonymous>(): R|kotlin/Number| <inline=NoInline>  {
+        ^ (Int(2) as R|kotlin/Number|)
+    }
+    )
+        public get(): R|kotlin/Number| {
+            ^ D|/thingWithDelefate|.R|kotlin/getValue|<R|kotlin/Number|>(Null(null), ::R|/thingWithDelefate|)
+        }

compiler/fir/analysis-tests/testData/resolveWithStdlib/properties/backingField/explicitBackingFieldsWithDelegates.kt

@@ -0,0 +1,2 @@
+val thingWithDelefate by lazy { 2 as Number }
+    <!BACKING_FIELD_FOR_DELEGATED_PROPERTY!>field<!> = 10

compiler/fir/analysis-tests/testData/resolveWithStdlib/properties/backingField/filePrivateBackingFieldAccess.fir.txt

@@ -0,0 +1,6 @@
+FILE: filePrivateBackingFieldAccess.kt
+    public final val list: R|kotlin/collections/List<kotlin/String>|
+        public get(): R|kotlin/collections/List<kotlin/String>|
+    public final fun add(s: R|kotlin/String|): R|kotlin/Unit| {
+        R|/list|.R|SubstitutionOverride<kotlin/collections/MutableList.add: R|kotlin/Boolean|>|(R|<local>/s|)
+    }

compiler/fir/analysis-tests/testData/resolveWithStdlib/properties/backingField/filePrivateBackingFieldAccess.kt

@@ -0,0 +1,6 @@
+val list: List<String>
+    field = mutableListOf<String>()
+
+fun add(s: String) {
+    list.add(s)
+}

compiler/fir/analysis-tests/testData/resolveWithStdlib/properties/backingField/lateinitBackingFields.fir.txt

@@ -0,0 +1,31 @@
+FILE: lateinitBackingFields.kt
+    public final var that: R|kotlin/Int|
+        public get(): R|kotlin/Int| {
+            ^ F|/that|.R|kotlin/String.length|
+        }
+        public set(value: R|kotlin/Int|): R|kotlin/Unit| {
+            F|/that| = R|<local>/value|.R|kotlin/Any.toString|()
+        }
+    public final fun test(): R|kotlin/Unit| {
+        R|/that| = Int(1)
+        R|kotlin/io/println|(R|/that|)
+    }
+    public final lateinit var number: R|kotlin/Number|
+        public get(): R|kotlin/Number|
+        public set(value: R|kotlin/Number|): R|kotlin/Unit| {
+            F|/number| = Int(10)
+        }
+    public final val something: R|kotlin/Number|
+        public get(): R|kotlin/Number|
+    public final lateinit var oneMore: R|kotlin/Number|
+        public get(): R|kotlin/Number|
+        public set(value: R|kotlin/Number|): R|kotlin/Unit| {
+            F|/oneMore| = Int(10)
+        }
+    public final var thingWithNullableField: R|kotlin/Number|
+        public get(): R|kotlin/Number| {
+            ^ Int(20)
+        }
+        public set(value: R|kotlin/Number|): R|kotlin/Unit| {
+            F|/thingWithNullableField| = R|<local>/value|.R|kotlin/Any.toString|()
+        }

compiler/fir/analysis-tests/testData/resolveWithStdlib/properties/backingField/lateinitBackingFields.kt

@@ -0,0 +1,35 @@
+var that: Int
+    lateinit field: String
+    get() = field.length
+    set(value) {
+        field = value.toString()
+    }
+
+fun test() {
+    that = 1
+    println(that)
+}
+
+// Not allowed for properties with
+// custom accessors
+<!INAPPLICABLE_LATEINIT_MODIFIER!>lateinit<!> var number: Number
+    field = 4
+    set(value) {
+        field = 10
+    }
+
+val something: Number
+    <!LATEINIT_FIELD_IN_VAL_PROPERTY, LATEINIT_PROPERTY_FIELD_DECLARATION_WITH_INITIALIZER!>lateinit<!> field = 4
+
+<!INAPPLICABLE_LATEINIT_MODIFIER!>lateinit<!> var oneMore: Number
+    <!LATEINIT_PROPERTY_FIELD_DECLARATION_WITH_INITIALIZER!>lateinit<!> field = 4
+    set(value) {
+        field = 10
+    }
+
+var thingWithNullableField: Number
+    <!LATEINIT_NULLABLE_BACKING_FIELD!>lateinit<!> field: String?
+    get() = 20
+    set(value) {
+        field = value.toString()
+    }

compiler/fir/analysis-tests/testData/resolveWithStdlib/properties/backingField/localVariablesWithBackingFields.fir.txt

@@ -0,0 +1,31 @@
+FILE: localVariablesWithBackingFields.kt
+    public final val that: R|kotlin/Number|
+        public get(): R|kotlin/Number|
+    public final fun test(): R|kotlin/Unit| {
+        lval a: R|kotlin/Number|
+        <Unresolved name: field># = Int(1)
+        lval b: R|kotlin/Number|by R|kotlin/lazy|<R|kotlin/Int|>(<L> = lazy@fun <anonymous>(): R|kotlin/Int| <inline=NoInline>  {
+            ^ Int(2)
+        }
+        )
+        <Unresolved name: field># = Int(10)
+    }
+    public final class A : R|kotlin/Any| {
+        public constructor(): R|A| {
+            super<R|kotlin/Any|>()
+        }
+
+        public final val c: R|kotlin/Number|by R|kotlin/lazy|<R|kotlin/Int|>(<L> = lazy@fun <anonymous>(): R|kotlin/Int| <inline=NoInline>  {
+            ^ Int(2)
+        }
+        )
+            public get(): R|kotlin/Number| {
+                ^ this@R|/A|.D|/A.c|.R|kotlin/getValue|<R|kotlin/Int|>(this@R|/A|, ::R|/A.c|)
+            }
+
+    }
+    public final val R|A|.cc: R|kotlin/Number|
+        public get(): R|kotlin/Number|
+    public final fun R|A|.cc(): R|kotlin/Unit| {
+        lval it: <ERROR TYPE REF: Ambiguity: plus, [kotlin/plus, kotlin/collections/plus, kotlin/collections/plus, kotlin/collections/plus, kotlin/collections/plus, kotlin/collections/plus, kotlin/collections/plus, kotlin/collections/plus, kotlin/collections/plus, kotlin/sequences/plus]> = <Unresolved name: a>#.<Ambiguity: plus, [kotlin/plus, kotlin/collections/plus, kotlin/collections/plus, kotlin/collections/plus, kotlin/collections/plus, kotlin/collections/plus, kotlin/collections/plus, kotlin/collections/plus, kotlin/collections/plus, kotlin/sequences/plus]>#(Int(2))
+    }

compiler/fir/analysis-tests/testData/resolveWithStdlib/properties/backingField/localVariablesWithBackingFields.kt

@@ -0,0 +1,22 @@
+val that: Number
+    field = 239
+
+fun test() {
+    val a: Number
+        <!UNRESOLVED_REFERENCE!>field<!> = 1
+
+    val b: Number by lazy { 2 }
+        <!UNRESOLVED_REFERENCE!>field<!> = 10
+}
+
+class A {
+    val c: Number by lazy { 2 }
+        <!BACKING_FIELD_FOR_DELEGATED_PROPERTY!>field<!> = 10
+}
+
+val A.cc: Number
+    <!EXPLICIT_BACKING_FIELD_IN_EXTENSION!>field<!> = 10
+
+fun A.cc() {
+    val it = <!UNRESOLVED_REFERENCE!>a<!> + 2
+}

compiler/fir/analysis-tests/testData/resolveWithStdlib/properties/backingField/overriddenPropertiesWithExplicitBackingFields.fir.txt

@@ -0,0 +1,30 @@
+FILE: overriddenPropertiesWithExplicitBackingFields.kt
+    public open class A : R|kotlin/Any| {
+        public constructor(): R|A| {
+            super<R|kotlin/Any|>()
+        }
+
+        public open var it: R|kotlin/Number|
+            public get(): R|kotlin/Number|
+            public set(value: R|kotlin/Number|): R|kotlin/Unit| {
+                this@R|/A|.F|/A.it| = R|<local>/value|.R|kotlin/Number.toInt|()
+            }
+
+        public final fun test(): R|kotlin/Unit| {
+            <Ambiguity: println, [kotlin/io/println, kotlin/io/println, kotlin/io/println, kotlin/io/println, kotlin/io/println, kotlin/io/println, kotlin/io/println, kotlin/io/println, kotlin/io/println, kotlin/io/println]>#(this@R|/A|.R|/A.it|.<Unresolved name: plus>#(Int(1)))
+        }
+
+    }
+    public open class B : R|A| {
+        public constructor(): R|B| {
+            super<R|A|>()
+        }
+
+        public open override var it: R|kotlin/Number|
+            public get(): R|kotlin/Number| {
+                ^ Double(3.14)
+            }
+            public set(value: R|kotlin/Number|): R|kotlin/Unit| {
+            }
+
+    }

compiler/fir/analysis-tests/testData/resolveWithStdlib/properties/backingField/overriddenPropertiesWithExplicitBackingFields.kt

@@ -0,0 +1,20 @@
+open class A {
+    open var it: Number
+        private field = 3
+        set(value) {
+            field = value.toInt()
+        }
+
+    fun test() {
+        // error, because `it` is not
+        // final, so no smart type narrowing
+        // is provided
+        <!OVERLOAD_RESOLUTION_AMBIGUITY!>println<!>(it <!UNRESOLVED_REFERENCE!>+<!> 1)
+    }
+}
+
+open class B : A() {
+    override var it: Number
+        get() = 3.14
+        set(value) {}
+}

compiler/fir/analysis-tests/testData/resolveWithStdlib/properties/backingField/propertyTypeNarrowing.fir.txt

@@ -0,0 +1,24 @@
+FILE: propertyTypeNarrowing.kt
+    public final class A : R|kotlin/Any| {
+        public constructor(): R|A| {
+            super<R|kotlin/Any|>()
+        }
+
+        public final val it: R|kotlin/Number|
+            public get(): R|kotlin/Number|
+
+        public final fun test(): R|kotlin/Int| {
+            ^test this@R|/A|.R|/A.it|.R|kotlin/Int.plus|(Int(3))
+        }
+
+        public final val p: R|kotlin/Int| = Int(5)
+            public get(): R|kotlin/Int| {
+                ^ this@R|/A|.F|/A.p|
+            }
+
+    }
+    public final fun test(): R|kotlin/Unit| {
+        lval c: <ERROR TYPE REF: Unresolved name: plus> = R|/A.A|().R|/A.it|.<Unresolved name: plus>#(Int(1))
+        lval d: R|kotlin/Unit| = R|/test|()
+        lval b: R|kotlin/Int| = R|/A.A|().R|/A.p|.R|kotlin/Int.plus|(Int(2))
+    }

compiler/fir/analysis-tests/testData/resolveWithStdlib/properties/backingField/propertyTypeNarrowing.kt

@@ -0,0 +1,15 @@
+class A {
+    val it: Number
+        field = 4
+
+    fun test() = it + 3
+
+    val p = 5
+        get() = field
+}
+
+fun test() {
+    val c = A().it <!UNRESOLVED_REFERENCE!>+<!> 1
+    val d = test()
+    val b = A().p + 2
+}

compiler/fir/analysis-tests/testData/resolveWithStdlib/properties/backingField/randomWeirdBackingFields.fir.txt

@@ -0,0 +1,10 @@
+FILE: randomWeirdBackingFields.kt
+    public abstract class Some1 : R|kotlin/Any| {
+        public constructor(): R|Some1| {
+            super<R|kotlin/Any|>()
+        }
+
+        public abstract val foo: R|kotlin/collections/List<kotlin/Int>|
+            public get(): R|kotlin/collections/List<kotlin/Int>|
+
+    }

compiler/fir/analysis-tests/testData/resolveWithStdlib/properties/backingField/randomWeirdBackingFields.kt

@@ -0,0 +1,4 @@
+abstract class Some1 {
+    abstract val foo: List<Int>
+        internal <!EXPLICIT_BACKING_FIELD_IN_ABSTRACT_PROPERTY!>field<!> = mutableListOf<Int>()
+}

compiler/fir/analysis-tests/testData/resolveWithStdlib/properties/backingField/redundantExplicitBackingField.fir.txt

@@ -0,0 +1,3 @@
+FILE: redundantExplicitBackingField.kt
+    public final val it: R|kotlin/Int|
+        public get(): R|kotlin/Int|

compiler/fir/analysis-tests/testData/resolveWithStdlib/properties/backingField/redundantExplicitBackingField.kt

@@ -0,0 +1,2 @@
+val it: Int
+    <!REDUNDANT_EXPLICIT_BACKING_FIELD!>field<!> = 42

compiler/fir/analysis-tests/tests-gen/org/jetbrains/kotlin/test/runners/FirDiagnosticTestGenerated.java

@@ -5532,6 +5532,104 @@ public class FirDiagnosticTestGenerated extends AbstractFirDiagnosticTest {
             }
         }
 
+        @Nested
+        @TestMetadata("compiler/fir/analysis-tests/testData/resolveWithStdlib/properties")
+        @TestDataPath("$PROJECT_ROOT")
+        public class Properties {
+            @Test
+            public void testAllFilesPresentInProperties() throws Exception {
+                KtTestUtil.assertAllTestsPresentByMetadataWithExcluded(this.getClass(), new File("compiler/fir/analysis-tests/testData/resolveWithStdlib/properties"), Pattern.compile("^([^.]+)\\.kt$"), null, true);
+            }
+
+            @Nested
+            @TestMetadata("compiler/fir/analysis-tests/testData/resolveWithStdlib/properties/backingField")
+            @TestDataPath("$PROJECT_ROOT")
+            public class BackingField {
+                @Test
+                public void testAllFilesPresentInBackingField() throws Exception {
+                    KtTestUtil.assertAllTestsPresentByMetadataWithExcluded(this.getClass(), new File("compiler/fir/analysis-tests/testData/resolveWithStdlib/properties/backingField"), Pattern.compile("^([^.]+)\\.kt$"), null, true);
+                }
+
+                @Test
+                @TestMetadata("backingFieldModifiers.kt")
+                public void testBackingFieldModifiers() throws Exception {
+                    runTest("compiler/fir/analysis-tests/testData/resolveWithStdlib/properties/backingField/backingFieldModifiers.kt");
+                }
+
+                @Test
+                @TestMetadata("backingFieldVisibility.kt")
+                public void testBackingFieldVisibility() throws Exception {
+                    runTest("compiler/fir/analysis-tests/testData/resolveWithStdlib/properties/backingField/backingFieldVisibility.kt");
+                }
+
+                @Test
+                @TestMetadata("backingFieldWithSmartTypeParameters.kt")
+                public void testBackingFieldWithSmartTypeParameters() throws Exception {
+                    runTest("compiler/fir/analysis-tests/testData/resolveWithStdlib/properties/backingField/backingFieldWithSmartTypeParameters.kt");
+                }
+
+                @Test
+                @TestMetadata("explicitBackingFieldInInterface.kt")
+                public void testExplicitBackingFieldInInterface() throws Exception {
+                    runTest("compiler/fir/analysis-tests/testData/resolveWithStdlib/properties/backingField/explicitBackingFieldInInterface.kt");
+                }
+
+                @Test
+                @TestMetadata("explicitBackingFieldType.kt")
+                public void testExplicitBackingFieldType() throws Exception {
+                    runTest("compiler/fir/analysis-tests/testData/resolveWithStdlib/properties/backingField/explicitBackingFieldType.kt");
+                }
+
+                @Test
+                @TestMetadata("explicitBackingFieldsWithDelegates.kt")
+                public void testExplicitBackingFieldsWithDelegates() throws Exception {
+                    runTest("compiler/fir/analysis-tests/testData/resolveWithStdlib/properties/backingField/explicitBackingFieldsWithDelegates.kt");
+                }
+
+                @Test
+                @TestMetadata("filePrivateBackingFieldAccess.kt")
+                public void testFilePrivateBackingFieldAccess() throws Exception {
+                    runTest("compiler/fir/analysis-tests/testData/resolveWithStdlib/properties/backingField/filePrivateBackingFieldAccess.kt");
+                }
+
+                @Test
+                @TestMetadata("lateinitBackingFields.kt")
+                public void testLateinitBackingFields() throws Exception {
+                    runTest("compiler/fir/analysis-tests/testData/resolveWithStdlib/properties/backingField/lateinitBackingFields.kt");
+                }
+
+                @Test
+                @TestMetadata("localVariablesWithBackingFields.kt")
+                public void testLocalVariablesWithBackingFields() throws Exception {
+                    runTest("compiler/fir/analysis-tests/testData/resolveWithStdlib/properties/backingField/localVariablesWithBackingFields.kt");
+                }
+
+                @Test
+                @TestMetadata("overriddenPropertiesWithExplicitBackingFields.kt")
+                public void testOverriddenPropertiesWithExplicitBackingFields() throws Exception {
+                    runTest("compiler/fir/analysis-tests/testData/resolveWithStdlib/properties/backingField/overriddenPropertiesWithExplicitBackingFields.kt");
+                }
+
+                @Test
+                @TestMetadata("propertyTypeNarrowing.kt")
+                public void testPropertyTypeNarrowing() throws Exception {
+                    runTest("compiler/fir/analysis-tests/testData/resolveWithStdlib/properties/backingField/propertyTypeNarrowing.kt");
+                }
+
+                @Test
+                @TestMetadata("randomWeirdBackingFields.kt")
+                public void testRandomWeirdBackingFields() throws Exception {
+                    runTest("compiler/fir/analysis-tests/testData/resolveWithStdlib/properties/backingField/randomWeirdBackingFields.kt");
+                }
+
+                @Test
+                @TestMetadata("redundantExplicitBackingField.kt")
+                public void testRedundantExplicitBackingField() throws Exception {
+                    runTest("compiler/fir/analysis-tests/testData/resolveWithStdlib/properties/backingField/redundantExplicitBackingField.kt");
+                }
+            }
+        }
+
         @Nested
         @TestMetadata("compiler/fir/analysis-tests/testData/resolveWithStdlib/reinitializations")
         @TestDataPath("$PROJECT_ROOT")

compiler/fir/analysis-tests/tests-gen/org/jetbrains/kotlin/test/runners/FirDiagnosticsWithLightTreeTestGenerated.java

@@ -5532,6 +5532,104 @@ public class FirDiagnosticsWithLightTreeTestGenerated extends AbstractFirDiagnos
             }
         }
 
+        @Nested
+        @TestMetadata("compiler/fir/analysis-tests/testData/resolveWithStdlib/properties")
+        @TestDataPath("$PROJECT_ROOT")
+        public class Properties {
+            @Test
+            public void testAllFilesPresentInProperties() throws Exception {
+                KtTestUtil.assertAllTestsPresentByMetadataWithExcluded(this.getClass(), new File("compiler/fir/analysis-tests/testData/resolveWithStdlib/properties"), Pattern.compile("^([^.]+)\\.kt$"), null, true);
+            }
+
+            @Nested
+            @TestMetadata("compiler/fir/analysis-tests/testData/resolveWithStdlib/properties/backingField")
+            @TestDataPath("$PROJECT_ROOT")
+            public class BackingField {
+                @Test
+                public void testAllFilesPresentInBackingField() throws Exception {
+                    KtTestUtil.assertAllTestsPresentByMetadataWithExcluded(this.getClass(), new File("compiler/fir/analysis-tests/testData/resolveWithStdlib/properties/backingField"), Pattern.compile("^([^.]+)\\.kt$"), null, true);
+                }
+
+                @Test
+                @TestMetadata("backingFieldModifiers.kt")
+                public void testBackingFieldModifiers() throws Exception {
+                    runTest("compiler/fir/analysis-tests/testData/resolveWithStdlib/properties/backingField/backingFieldModifiers.kt");
+                }
+
+                @Test
+                @TestMetadata("backingFieldVisibility.kt")
+                public void testBackingFieldVisibility() throws Exception {
+                    runTest("compiler/fir/analysis-tests/testData/resolveWithStdlib/properties/backingField/backingFieldVisibility.kt");
+                }
+
+                @Test
+                @TestMetadata("backingFieldWithSmartTypeParameters.kt")
+                public void testBackingFieldWithSmartTypeParameters() throws Exception {
+                    runTest("compiler/fir/analysis-tests/testData/resolveWithStdlib/properties/backingField/backingFieldWithSmartTypeParameters.kt");
+                }
+
+                @Test
+                @TestMetadata("explicitBackingFieldInInterface.kt")
+                public void testExplicitBackingFieldInInterface() throws Exception {
+                    runTest("compiler/fir/analysis-tests/testData/resolveWithStdlib/properties/backingField/explicitBackingFieldInInterface.kt");
+                }
+
+                @Test
+                @TestMetadata("explicitBackingFieldType.kt")
+                public void testExplicitBackingFieldType() throws Exception {
+                    runTest("compiler/fir/analysis-tests/testData/resolveWithStdlib/properties/backingField/explicitBackingFieldType.kt");
+                }
+
+                @Test
+                @TestMetadata("explicitBackingFieldsWithDelegates.kt")
+                public void testExplicitBackingFieldsWithDelegates() throws Exception {
+                    runTest("compiler/fir/analysis-tests/testData/resolveWithStdlib/properties/backingField/explicitBackingFieldsWithDelegates.kt");
+                }
+
+                @Test
+                @TestMetadata("filePrivateBackingFieldAccess.kt")
+                public void testFilePrivateBackingFieldAccess() throws Exception {
+                    runTest("compiler/fir/analysis-tests/testData/resolveWithStdlib/properties/backingField/filePrivateBackingFieldAccess.kt");
+                }
+
+                @Test
+                @TestMetadata("lateinitBackingFields.kt")
+                public void testLateinitBackingFields() throws Exception {
+                    runTest("compiler/fir/analysis-tests/testData/resolveWithStdlib/properties/backingField/lateinitBackingFields.kt");
+                }
+
+                @Test
+                @TestMetadata("localVariablesWithBackingFields.kt")
+                public void testLocalVariablesWithBackingFields() throws Exception {
+                    runTest("compiler/fir/analysis-tests/testData/resolveWithStdlib/properties/backingField/localVariablesWithBackingFields.kt");
+                }
+
+                @Test
+                @TestMetadata("overriddenPropertiesWithExplicitBackingFields.kt")
+                public void testOverriddenPropertiesWithExplicitBackingFields() throws Exception {
+                    runTest("compiler/fir/analysis-tests/testData/resolveWithStdlib/properties/backingField/overriddenPropertiesWithExplicitBackingFields.kt");
+                }
+
+                @Test
+                @TestMetadata("propertyTypeNarrowing.kt")
+                public void testPropertyTypeNarrowing() throws Exception {
+                    runTest("compiler/fir/analysis-tests/testData/resolveWithStdlib/properties/backingField/propertyTypeNarrowing.kt");
+                }
+
+                @Test
+                @TestMetadata("randomWeirdBackingFields.kt")
+                public void testRandomWeirdBackingFields() throws Exception {
+                    runTest("compiler/fir/analysis-tests/testData/resolveWithStdlib/properties/backingField/randomWeirdBackingFields.kt");
+                }
+
+                @Test
+                @TestMetadata("redundantExplicitBackingField.kt")
+                public void testRedundantExplicitBackingField() throws Exception {
+                    runTest("compiler/fir/analysis-tests/testData/resolveWithStdlib/properties/backingField/redundantExplicitBackingField.kt");
+                }
+            }
+        }
+
         @Nested
         @TestMetadata("compiler/fir/analysis-tests/testData/resolveWithStdlib/reinitializations")
         @TestDataPath("$PROJECT_ROOT")

compiler/fir/analysis-tests/tests-gen/org/jetbrains/kotlin/test/runners/FirOldFrontendDiagnosticsTestGenerated.java

@@ -22485,6 +22485,22 @@ public class FirOldFrontendDiagnosticsTestGenerated extends AbstractFirDiagnosti
                 runTest("compiler/testData/diagnostics/tests/properties/lateinitOnTopLevel.kt");
             }
 
+            @Nested
+            @TestMetadata("compiler/testData/diagnostics/tests/properties/backingField")
+            @TestDataPath("$PROJECT_ROOT")
+            public class BackingField {
+                @Test
+                public void testAllFilesPresentInBackingField() throws Exception {
+                    KtTestUtil.assertAllTestsPresentByMetadataWithExcluded(this.getClass(), new File("compiler/testData/diagnostics/tests/properties/backingField"), Pattern.compile("^(.+)\\.kt$"), Pattern.compile("^(.+)\\.fir\\.kts?$"), true);
+                }
+
+                @Test
+                @TestMetadata("trivialExplicitBackingFIeld.kt")
+                public void testTrivialExplicitBackingFIeld() throws Exception {
+                    runTest("compiler/testData/diagnostics/tests/properties/backingField/trivialExplicitBackingFIeld.kt");
+                }
+            }
+
             @Nested
             @TestMetadata("compiler/testData/diagnostics/tests/properties/inferenceFromGetters")
             @TestDataPath("$PROJECT_ROOT")

compiler/fir/analysis-tests/tests-gen/org/jetbrains/kotlin/test/runners/FirOldFrontendDiagnosticsWithLightTreeTestGenerated.java

@@ -22485,6 +22485,22 @@ public class FirOldFrontendDiagnosticsWithLightTreeTestGenerated extends Abstrac
                 runTest("compiler/testData/diagnostics/tests/properties/lateinitOnTopLevel.kt");
             }
 
+            @Nested
+            @TestMetadata("compiler/testData/diagnostics/tests/properties/backingField")
+            @TestDataPath("$PROJECT_ROOT")
+            public class BackingField {
+                @Test
+                public void testAllFilesPresentInBackingField() throws Exception {
+                    KtTestUtil.assertAllTestsPresentByMetadataWithExcluded(this.getClass(), new File("compiler/testData/diagnostics/tests/properties/backingField"), Pattern.compile("^(.+)\\.kt$"), Pattern.compile("^(.+)\\.fir\\.kts?$"), true);
+                }
+
+                @Test
+                @TestMetadata("trivialExplicitBackingFIeld.kt")
+                public void testTrivialExplicitBackingFIeld() throws Exception {
+                    runTest("compiler/testData/diagnostics/tests/properties/backingField/trivialExplicitBackingFIeld.kt");
+                }
+            }
+
             @Nested
             @TestMetadata("compiler/testData/diagnostics/tests/properties/inferenceFromGetters")
             @TestDataPath("$PROJECT_ROOT")

compiler/fir/fir2ir/src/org/jetbrains/kotlin/fir/backend/Fir2IrDeclarationStorage.kt

@@ -610,13 +610,7 @@ class Fir2IrDeclarationStorage(
             signature,
             containerSource
         ) { symbol ->
-            val accessorReturnType = if (isSetter) {
-                irBuiltIns.unitType
-            } else if (property.canNarrowDownGetterType) {
-                property.backingField?.returnTypeRef?.toIrType() ?: propertyType
-            } else {
-                propertyType
-            }
+            val accessorReturnType = if (isSetter) irBuiltIns.unitType else propertyType
             val visibility = propertyAccessor?.visibility?.let {
                 components.visibilityConverter.convertToDescriptorVisibility(it)
             }

compiler/fir/fir2ir/testData/codegen/box/properties/backingField/backingFieldVisibility.kt

@@ -0,0 +1,15 @@
+class A {
+    val a: Number
+        private field = 1
+
+    val b: Number
+        internal field = a + 3
+}
+
+fun box(): String {
+    return if (A().b + 20 == 24) {
+        "OK"
+    } else {
+        "fail: A().b = " + A().b.toString()
+    }
+}

compiler/fir/fir2ir/testData/codegen/box/properties/backingField/charSequenceWithBackingField1.kt

@@ -0,0 +1,8 @@
+class Base {
+    val x: CharSequence
+        internal field: String = "OK"
+}
+
+fun box(): String {
+    return Base().x
+}

compiler/fir/fir2ir/testData/codegen/box/properties/backingField/charSequenceWithBackingField2.kt

@@ -0,0 +1,10 @@
+class Base {
+    val x: CharSequence
+        internal field: String = "OK"
+
+    val s: String get() = x
+}
+
+fun box(): String {
+    return Base().s
+}

compiler/fir/fir2ir/testData/codegen/box/properties/backingField/charSequenceWithBackingField3.kt

@@ -0,0 +1,9 @@
+class Base {
+    val x: CharSequence
+        internal field: String = "OK"
+
+}
+val s: String get() = Base().x
+fun box(): String {
+    return s
+}

compiler/fir/fir2ir/testData/codegen/box/properties/backingField/charSequenceWithBackingField4.kt

@@ -0,0 +1,9 @@
+class Base {
+    val x: CharSequence
+        internal field: String = "OK"
+
+}
+val s: String = Base().x
+fun box(): String {
+    return s
+}

compiler/fir/fir2ir/testData/codegen/box/properties/backingField/charSequenceWithBackingField5.kt

@@ -0,0 +1,13 @@
+open class Base {
+    open val x: CharSequence = "BASE"
+         // field = "BASE"
+}
+
+class Ok : Base() {
+    override val x: CharSequence
+        internal field: String = "OK"
+}
+
+fun box(): String {
+    return Ok().x
+}

compiler/fir/fir2ir/testData/codegen/box/properties/backingField/explicitBackingFieldInAnonymous.kt

@@ -0,0 +1,59 @@
+interface I {
+    val number: Number
+}
+
+fun test1(): String? {
+    val it = object : I {
+        final override val number: Number
+            field = 10
+
+        val next get() = number + 1
+    }
+
+    return if (it.next != 11) {
+        "[1] ${it.number}, ${it.next}"
+    } else {
+        null
+    }
+}
+
+fun test2(): String? {
+    class Local : I {
+        final override val number: Number
+            internal field = 42
+    }
+
+    return if (Local().number + 3 != 45) {
+        "[2] " + Local().number.toString()
+    } else {
+        null
+    }
+}
+
+fun test3(): String? {
+    val it = object : I {
+        override val number: Number
+            field = "100"
+            get() {
+                return field.length
+            }
+    }
+
+    return if (it.number != 3) {
+        "[3] " + it.number.toString()
+    } else {
+        null
+    }
+}
+
+fun box(): String {
+    val problem = test1()
+        ?: test2()
+        ?: test3()
+
+    return if (problem != null) {
+        "fail: " + problem
+    } else {
+        "OK"
+    }
+}

compiler/fir/fir2ir/testData/codegen/box/properties/backingField/getterReturnTypeWithBackingField.kt

@@ -0,0 +1,22 @@
+interface Storage {
+    val s: String
+}
+
+class ImmutableStorage(override val s: String) : Storage
+class MutableStorage(override var s: String) : Storage {
+    fun asImmutable() = ImmutableStorage(s)
+}
+
+class My {
+    val storage: Storage
+        field = MutableStorage("OK")
+        get() = field.asImmutable()
+}
+
+fun box(): String {
+    val my = My()
+    if (my.storage is MutableStorage) {
+        return "MUTABLE"
+    }
+    return my.storage.s
+}

compiler/fir/fir2ir/testData/codegen/box/properties/backingField/independentBackingFieldType.kt

@@ -0,0 +1,40 @@
+fun createString() = "AAA" + "BBB"
+
+class A {
+    var it: Int
+        field = 3.14
+        get() = (field + 10).toInt()
+        set(value) {
+            field = (value - 10).toDouble()
+
+            if (field < -3 || -1 < field) {
+                throw Exception("fail: value = $value, field = $field")
+            }
+        }
+
+    var that: Int
+        field = createString() + "!"
+        get() = field.length
+        set(value) {
+            field = value.toString()
+
+            if (field != "17") {
+                throw Exception("fail: value = $value, field = $field")
+            }
+        }
+}
+
+fun box(): String {
+    try {
+        val a = A()
+
+        val it: Int = A().it and 10
+        a.it = it
+
+        val that: Int = a.that
+        a.that = that + 10
+    } catch (e: Exception) {
+        return e.message ?: "fail"
+    }
+    return "OK"
+}

compiler/fir/fir2ir/testData/codegen/box/properties/backingField/lateinitBackingFields.kt

@@ -0,0 +1,16 @@
+var that: Int
+    lateinit field: String
+    get() = field.length
+    set(value) {
+        field = value.toString()
+    }
+
+fun box(): String {
+    that = 1
+
+    return if (that == 1) {
+        "OK"
+    } else {
+        "fail: $that"
+    }
+}

compiler/fir/fir2ir/testData/codegen/box/properties/backingField/overriddenPropertiesWithExplicitBackingFields.kt

@@ -0,0 +1,30 @@
+open class A {
+    open var it: Number
+        private field = 3
+        set(value) {
+            field = value.toInt()
+        }
+
+    fun test(): String {
+        // Note that `it` is open,
+        // so no smart type narrowing
+        // is possible, and we expect
+        // here a call to the possibly
+        // overridden getter
+        return if (it.toInt() + 1 == 11) {
+            "OK"
+        } else {
+            "fail: $it"
+        }
+    }
+}
+
+open class B : A() {
+    override var it: Number
+        get() = 10.12
+        set(value) {}
+}
+
+fun box(): String {
+    return B().test()
+}

compiler/fir/fir2ir/testData/codegen/boxWithStdLib/properties/backingField/backingFieldWithSmartTypeParameters.kt

@@ -0,0 +1,7 @@
+val items: List<String>
+    field = mutableListOf()
+
+fun box(): String {
+    items.add("OK")
+    return items.last()
+}

compiler/fir/fir2ir/testData/codegen/bytecodeListing/explicitBackingFieldsInJava.kt

@@ -0,0 +1,13 @@
+// MODULE: ModuleA
+// FILE: AI.kt
+
+public interface AI {
+    val number: Number
+}
+
+// FILE: AC.kt
+
+public class AC : AI {
+    final override val number: Number
+        field = 4
+}

compiler/fir/fir2ir/testData/codegen/bytecodeListing/explicitBackingFieldsInJava.txt

@@ -0,0 +1,13 @@
+@kotlin.Metadata
+public final class AC {
+    // source: 'AC.kt'
+    private final field number: int
+    public method <init>(): void
+    public final @org.jetbrains.annotations.NotNull method getNumber(): java.lang.Number
+}
+
+@kotlin.Metadata
+public interface AI {
+    // source: 'AI.kt'
+    public abstract @org.jetbrains.annotations.NotNull method getNumber(): java.lang.Number
+}

compiler/fir/fir2ir/testData/ir/irText/properties/backingField/backingFieldVisibility.kt

@@ -0,0 +1,21 @@
+// FIR_IDENTICAL
+
+class A {
+    val a: Number
+        private field = 1
+
+    val b: Number
+        internal field = a + 2
+
+    val c = 1
+    val d = c + 2
+
+    fun rest() {
+        val aI = A().a + 10
+        val bI = A().b + 20
+    }
+}
+
+fun test() {
+    val bA = A().b + 20
+}

compiler/fir/fir2ir/testData/ir/irText/properties/backingField/backingFieldVisibility.kt.txt

@@ -0,0 +1,34 @@
+class A {
+  constructor() /* primary */ {
+    super/*Any*/()
+    /* <init>() */
+
+  }
+
+  val a: Int
+    field = 1
+    get
+
+  val b: Int
+    field = <this>.<get-a>().plus(other = 2)
+    get
+
+  val c: Int
+    field = 1
+    get
+
+  val d: Int
+    field = <this>.<get-c>().plus(other = 2)
+    get
+
+  fun rest() {
+    val aI: Int = A().<get-a>().plus(other = 10)
+    val bI: Int = A().<get-b>().plus(other = 20)
+  }
+
+}
+
+fun test() {
+  val bA: Int = A().<get-b>().plus(other = 20)
+}
+

compiler/fir/fir2ir/testData/ir/irText/properties/backingField/backingFieldVisibility.txt

@@ -0,0 +1,90 @@
+FILE fqName:<root> fileName:/backingFieldVisibility.kt
+  CLASS CLASS name:A modality:FINAL visibility:public superTypes:[kotlin.Any]
+    $this: VALUE_PARAMETER INSTANCE_RECEIVER name:<this> type:<root>.A
+    CONSTRUCTOR visibility:public <> () returnType:<root>.A [primary]
+      BLOCK_BODY
+        DELEGATING_CONSTRUCTOR_CALL 'public constructor <init> () [primary] declared in kotlin.Any'
+        INSTANCE_INITIALIZER_CALL classDescriptor='CLASS CLASS name:A modality:FINAL visibility:public superTypes:[kotlin.Any]'
+    PROPERTY name:a visibility:public modality:FINAL [val]
+      FIELD PROPERTY_BACKING_FIELD name:a type:kotlin.Int visibility:private [final]
+        EXPRESSION_BODY
+          CONST Int type=kotlin.Int value=1
+      FUN DEFAULT_PROPERTY_ACCESSOR name:<get-a> visibility:public modality:FINAL <> ($this:<root>.A) returnType:kotlin.Number
+        correspondingProperty: PROPERTY name:a visibility:public modality:FINAL [val]
+        $this: VALUE_PARAMETER name:<this> type:<root>.A
+        BLOCK_BODY
+          RETURN type=kotlin.Nothing from='public final fun <get-a> (): kotlin.Number declared in <root>.A'
+            GET_FIELD 'FIELD PROPERTY_BACKING_FIELD name:a type:kotlin.Int visibility:private [final]' type=kotlin.Number origin=null
+              receiver: GET_VAR '<this>: <root>.A declared in <root>.A.<get-a>' type=<root>.A origin=null
+    PROPERTY name:b visibility:public modality:FINAL [val]
+      FIELD PROPERTY_BACKING_FIELD name:b type:kotlin.Int visibility:internal [final]
+        EXPRESSION_BODY
+          CALL 'public final fun plus (other: kotlin.Int): kotlin.Int [operator] declared in kotlin.Int' type=kotlin.Int origin=PLUS
+            $this: CALL 'public final fun <get-a> (): kotlin.Number declared in <root>.A' type=kotlin.Int origin=GET_PROPERTY
+              $this: GET_VAR '<this>: <root>.A declared in <root>.A' type=<root>.A origin=null
+            other: CONST Int type=kotlin.Int value=2
+      FUN DEFAULT_PROPERTY_ACCESSOR name:<get-b> visibility:public modality:FINAL <> ($this:<root>.A) returnType:kotlin.Number
+        correspondingProperty: PROPERTY name:b visibility:public modality:FINAL [val]
+        $this: VALUE_PARAMETER name:<this> type:<root>.A
+        BLOCK_BODY
+          RETURN type=kotlin.Nothing from='public final fun <get-b> (): kotlin.Number declared in <root>.A'
+            GET_FIELD 'FIELD PROPERTY_BACKING_FIELD name:b type:kotlin.Int visibility:internal [final]' type=kotlin.Number origin=null
+              receiver: GET_VAR '<this>: <root>.A declared in <root>.A.<get-b>' type=<root>.A origin=null
+    PROPERTY name:c visibility:public modality:FINAL [val]
+      FIELD PROPERTY_BACKING_FIELD name:c type:kotlin.Int visibility:private [final]
+        EXPRESSION_BODY
+          CONST Int type=kotlin.Int value=1
+      FUN DEFAULT_PROPERTY_ACCESSOR name:<get-c> visibility:public modality:FINAL <> ($this:<root>.A) returnType:kotlin.Int
+        correspondingProperty: PROPERTY name:c visibility:public modality:FINAL [val]
+        $this: VALUE_PARAMETER name:<this> type:<root>.A
+        BLOCK_BODY
+          RETURN type=kotlin.Nothing from='public final fun <get-c> (): kotlin.Int declared in <root>.A'
+            GET_FIELD 'FIELD PROPERTY_BACKING_FIELD name:c type:kotlin.Int visibility:private [final]' type=kotlin.Int origin=null
+              receiver: GET_VAR '<this>: <root>.A declared in <root>.A.<get-c>' type=<root>.A origin=null
+    PROPERTY name:d visibility:public modality:FINAL [val]
+      FIELD PROPERTY_BACKING_FIELD name:d type:kotlin.Int visibility:private [final]
+        EXPRESSION_BODY
+          CALL 'public final fun plus (other: kotlin.Int): kotlin.Int [operator] declared in kotlin.Int' type=kotlin.Int origin=PLUS
+            $this: CALL 'public final fun <get-c> (): kotlin.Int declared in <root>.A' type=kotlin.Int origin=GET_PROPERTY
+              $this: GET_VAR '<this>: <root>.A declared in <root>.A' type=<root>.A origin=null
+            other: CONST Int type=kotlin.Int value=2
+      FUN DEFAULT_PROPERTY_ACCESSOR name:<get-d> visibility:public modality:FINAL <> ($this:<root>.A) returnType:kotlin.Int
+        correspondingProperty: PROPERTY name:d visibility:public modality:FINAL [val]
+        $this: VALUE_PARAMETER name:<this> type:<root>.A
+        BLOCK_BODY
+          RETURN type=kotlin.Nothing from='public final fun <get-d> (): kotlin.Int declared in <root>.A'
+            GET_FIELD 'FIELD PROPERTY_BACKING_FIELD name:d type:kotlin.Int visibility:private [final]' type=kotlin.Int origin=null
+              receiver: GET_VAR '<this>: <root>.A declared in <root>.A.<get-d>' type=<root>.A origin=null
+    FUN name:rest visibility:public modality:FINAL <> ($this:<root>.A) returnType:kotlin.Unit
+      $this: VALUE_PARAMETER name:<this> type:<root>.A
+      BLOCK_BODY
+        VAR name:aI type:kotlin.Int [val]
+          CALL 'public final fun plus (other: kotlin.Int): kotlin.Int [operator] declared in kotlin.Int' type=kotlin.Int origin=PLUS
+            $this: CALL 'public final fun <get-a> (): kotlin.Number declared in <root>.A' type=kotlin.Int origin=GET_PROPERTY
+              $this: CONSTRUCTOR_CALL 'public constructor <init> () [primary] declared in <root>.A' type=<root>.A origin=null
+            other: CONST Int type=kotlin.Int value=10
+        VAR name:bI type:kotlin.Int [val]
+          CALL 'public final fun plus (other: kotlin.Int): kotlin.Int [operator] declared in kotlin.Int' type=kotlin.Int origin=PLUS
+            $this: CALL 'public final fun <get-b> (): kotlin.Number declared in <root>.A' type=kotlin.Int origin=GET_PROPERTY
+              $this: CONSTRUCTOR_CALL 'public constructor <init> () [primary] declared in <root>.A' type=<root>.A origin=null
+            other: CONST Int type=kotlin.Int value=20
+    FUN FAKE_OVERRIDE name:equals visibility:public modality:OPEN <> ($this:kotlin.Any, other:kotlin.Any?) returnType:kotlin.Boolean [fake_override,operator]
+      overridden:
+        public open fun equals (other: kotlin.Any?): kotlin.Boolean [operator] declared in kotlin.Any
+      $this: VALUE_PARAMETER name:<this> type:kotlin.Any
+      VALUE_PARAMETER name:other index:0 type:kotlin.Any?
+    FUN FAKE_OVERRIDE name:hashCode visibility:public modality:OPEN <> ($this:kotlin.Any) returnType:kotlin.Int [fake_override]
+      overridden:
+        public open fun hashCode (): kotlin.Int declared in kotlin.Any
+      $this: VALUE_PARAMETER name:<this> type:kotlin.Any
+    FUN FAKE_OVERRIDE name:toString visibility:public modality:OPEN <> ($this:kotlin.Any) returnType:kotlin.String [fake_override]
+      overridden:
+        public open fun toString (): kotlin.String declared in kotlin.Any
+      $this: VALUE_PARAMETER name:<this> type:kotlin.Any
+  FUN name:test visibility:public modality:FINAL <> () returnType:kotlin.Unit
+    BLOCK_BODY
+      VAR name:bA type:kotlin.Int [val]
+        CALL 'public final fun plus (other: kotlin.Int): kotlin.Int [operator] declared in kotlin.Int' type=kotlin.Int origin=PLUS
+          $this: CALL 'public final fun <get-b> (): kotlin.Number declared in <root>.A' type=kotlin.Int origin=GET_PROPERTY
+            $this: CONSTRUCTOR_CALL 'public constructor <init> () [primary] declared in <root>.A' type=<root>.A origin=null
+          other: CONST Int type=kotlin.Int value=20

compiler/fir/fir2ir/testData/ir/irText/properties/backingField/explicitBackingFieldType.kt

@@ -0,0 +1,14 @@
+// FIR_IDENTICAL
+class A {
+    val a = 20
+
+    val it: Number
+        field = 4
+
+    var invertedTypes: Int
+        field: Number = 42
+        get() = if (field.toInt() > 10) field.toInt() else 10
+
+    val p = 5
+        get() = field
+}

compiler/fir/fir2ir/testData/ir/irText/properties/backingField/explicitBackingFieldType.kt.txt

@@ -0,0 +1,33 @@
+class A {
+  constructor() /* primary */ {
+    super/*Any*/()
+    /* <init>() */
+
+  }
+
+  val a: Int
+    field = 20
+    get
+
+  val it: Int
+    field = 4
+    get
+
+  var invertedTypes: Number
+    field = 42
+    get(): Int {
+      return when {
+        greater(arg0 = <this>.#invertedTypes.toInt(), arg1 = 10) -> <this>.#invertedTypes.toInt()
+        else -> 10
+      }
+    }
+    set
+
+  val p: Int
+    field = 5
+    get(): Int {
+      return <this>.#p
+    }
+
+}
+

compiler/fir/fir2ir/testData/ir/irText/properties/backingField/explicitBackingFieldType.txt

@@ -0,0 +1,83 @@
+FILE fqName:<root> fileName:/explicitBackingFieldType.kt
+  CLASS CLASS name:A modality:FINAL visibility:public superTypes:[kotlin.Any]
+    $this: VALUE_PARAMETER INSTANCE_RECEIVER name:<this> type:<root>.A
+    CONSTRUCTOR visibility:public <> () returnType:<root>.A [primary]
+      BLOCK_BODY
+        DELEGATING_CONSTRUCTOR_CALL 'public constructor <init> () [primary] declared in kotlin.Any'
+        INSTANCE_INITIALIZER_CALL classDescriptor='CLASS CLASS name:A modality:FINAL visibility:public superTypes:[kotlin.Any]'
+    PROPERTY name:a visibility:public modality:FINAL [val]
+      FIELD PROPERTY_BACKING_FIELD name:a type:kotlin.Int visibility:private [final]
+        EXPRESSION_BODY
+          CONST Int type=kotlin.Int value=20
+      FUN DEFAULT_PROPERTY_ACCESSOR name:<get-a> visibility:public modality:FINAL <> ($this:<root>.A) returnType:kotlin.Int
+        correspondingProperty: PROPERTY name:a visibility:public modality:FINAL [val]
+        $this: VALUE_PARAMETER name:<this> type:<root>.A
+        BLOCK_BODY
+          RETURN type=kotlin.Nothing from='public final fun <get-a> (): kotlin.Int declared in <root>.A'
+            GET_FIELD 'FIELD PROPERTY_BACKING_FIELD name:a type:kotlin.Int visibility:private [final]' type=kotlin.Int origin=null
+              receiver: GET_VAR '<this>: <root>.A declared in <root>.A.<get-a>' type=<root>.A origin=null
+    PROPERTY name:it visibility:public modality:FINAL [val]
+      FIELD PROPERTY_BACKING_FIELD name:it type:kotlin.Int visibility:private [final]
+        EXPRESSION_BODY
+          CONST Int type=kotlin.Int value=4
+      FUN DEFAULT_PROPERTY_ACCESSOR name:<get-it> visibility:public modality:FINAL <> ($this:<root>.A) returnType:kotlin.Number
+        correspondingProperty: PROPERTY name:it visibility:public modality:FINAL [val]
+        $this: VALUE_PARAMETER name:<this> type:<root>.A
+        BLOCK_BODY
+          RETURN type=kotlin.Nothing from='public final fun <get-it> (): kotlin.Number declared in <root>.A'
+            GET_FIELD 'FIELD PROPERTY_BACKING_FIELD name:it type:kotlin.Int visibility:private [final]' type=kotlin.Number origin=null
+              receiver: GET_VAR '<this>: <root>.A declared in <root>.A.<get-it>' type=<root>.A origin=null
+    PROPERTY name:invertedTypes visibility:public modality:FINAL [var]
+      FIELD PROPERTY_BACKING_FIELD name:invertedTypes type:kotlin.Number visibility:private
+        EXPRESSION_BODY
+          CONST Int type=kotlin.Int value=42
+      FUN name:<get-invertedTypes> visibility:public modality:FINAL <> ($this:<root>.A) returnType:kotlin.Int
+        correspondingProperty: PROPERTY name:invertedTypes visibility:public modality:FINAL [var]
+        $this: VALUE_PARAMETER name:<this> type:<root>.A
+        BLOCK_BODY
+          RETURN type=kotlin.Nothing from='public final fun <get-invertedTypes> (): kotlin.Int declared in <root>.A'
+            WHEN type=kotlin.Int origin=IF
+              BRANCH
+                if: CALL 'public final fun greater (arg0: kotlin.Int, arg1: kotlin.Int): kotlin.Boolean declared in kotlin.internal.ir' type=kotlin.Boolean origin=GT
+                  arg0: CALL 'public abstract fun toInt (): kotlin.Int declared in kotlin.Number' type=kotlin.Int origin=null
+                    $this: GET_FIELD 'FIELD PROPERTY_BACKING_FIELD name:invertedTypes type:kotlin.Number visibility:private' type=kotlin.Number origin=GET_PROPERTY
+                      receiver: GET_VAR '<this>: <root>.A declared in <root>.A.<get-invertedTypes>' type=<root>.A origin=null
+                  arg1: CONST Int type=kotlin.Int value=10
+                then: CALL 'public abstract fun toInt (): kotlin.Int declared in kotlin.Number' type=kotlin.Int origin=null
+                  $this: GET_FIELD 'FIELD PROPERTY_BACKING_FIELD name:invertedTypes type:kotlin.Number visibility:private' type=kotlin.Number origin=GET_PROPERTY
+                    receiver: GET_VAR '<this>: <root>.A declared in <root>.A.<get-invertedTypes>' type=<root>.A origin=null
+              BRANCH
+                if: CONST Boolean type=kotlin.Boolean value=true
+                then: CONST Int type=kotlin.Int value=10
+      FUN DEFAULT_PROPERTY_ACCESSOR name:<set-invertedTypes> visibility:public modality:FINAL <> ($this:<root>.A, <set-?>:kotlin.Int) returnType:kotlin.Unit
+        correspondingProperty: PROPERTY name:invertedTypes visibility:public modality:FINAL [var]
+        $this: VALUE_PARAMETER name:<this> type:<root>.A
+        VALUE_PARAMETER name:<set-?> index:0 type:kotlin.Int
+        BLOCK_BODY
+          SET_FIELD 'FIELD PROPERTY_BACKING_FIELD name:invertedTypes type:kotlin.Number visibility:private' type=kotlin.Unit origin=null
+            receiver: GET_VAR '<this>: <root>.A declared in <root>.A.<set-invertedTypes>' type=<root>.A origin=null
+            value: GET_VAR '<set-?>: kotlin.Int declared in <root>.A.<set-invertedTypes>' type=kotlin.Int origin=null
+    PROPERTY name:p visibility:public modality:FINAL [val]
+      FIELD PROPERTY_BACKING_FIELD name:p type:kotlin.Int visibility:private [final]
+        EXPRESSION_BODY
+          CONST Int type=kotlin.Int value=5
+      FUN name:<get-p> visibility:public modality:FINAL <> ($this:<root>.A) returnType:kotlin.Int
+        correspondingProperty: PROPERTY name:p visibility:public modality:FINAL [val]
+        $this: VALUE_PARAMETER name:<this> type:<root>.A
+        BLOCK_BODY
+          RETURN type=kotlin.Nothing from='public final fun <get-p> (): kotlin.Int declared in <root>.A'
+            GET_FIELD 'FIELD PROPERTY_BACKING_FIELD name:p type:kotlin.Int visibility:private [final]' type=kotlin.Int origin=GET_PROPERTY
+              receiver: GET_VAR '<this>: <root>.A declared in <root>.A.<get-p>' type=<root>.A origin=null
+    FUN FAKE_OVERRIDE name:equals visibility:public modality:OPEN <> ($this:kotlin.Any, other:kotlin.Any?) returnType:kotlin.Boolean [fake_override,operator]
+      overridden:
+        public open fun equals (other: kotlin.Any?): kotlin.Boolean [operator] declared in kotlin.Any
+      $this: VALUE_PARAMETER name:<this> type:kotlin.Any
+      VALUE_PARAMETER name:other index:0 type:kotlin.Any?
+    FUN FAKE_OVERRIDE name:hashCode visibility:public modality:OPEN <> ($this:kotlin.Any) returnType:kotlin.Int [fake_override]
+      overridden:
+        public open fun hashCode (): kotlin.Int declared in kotlin.Any
+      $this: VALUE_PARAMETER name:<this> type:kotlin.Any
+    FUN FAKE_OVERRIDE name:toString visibility:public modality:OPEN <> ($this:kotlin.Any) returnType:kotlin.String [fake_override]
+      overridden:
+        public open fun toString (): kotlin.String declared in kotlin.Any
+      $this: VALUE_PARAMETER name:<this> type:kotlin.Any

compiler/fir/fir2ir/testData/ir/irText/properties/backingField/independentBackingFieldType.kt

@@ -0,0 +1,15 @@
+// FIR_IDENTICAL
+class A {
+    var it: Int
+        field = 3.14
+        get() = (field + 10).toInt()
+        set(value) {
+            field = (value - 10).toDouble()
+        }
+}
+
+fun test() {
+    val a = A()
+    val it: Int = A().it and 10
+    a.it = it
+}

compiler/fir/fir2ir/testData/ir/irText/properties/backingField/independentBackingFieldType.kt.txt

@@ -0,0 +1,23 @@
+class A {
+  constructor() /* primary */ {
+    super/*Any*/()
+    /* <init>() */
+
+  }
+
+  var it: Double
+    field = 3.14
+    get(): Int {
+      return <this>.#it.plus(other = 10).toInt()
+    }
+    set(value: Int) {
+      <this>.#it = value.minus(other = 10).toDouble()
+    }
+
+}
+
+fun test() {
+  val a: A = A()
+  val it: Int = A().<get-it>().and(other = 10)
+  a.<set-it>(value = it)
+}

compiler/fir/fir2ir/testData/ir/irText/properties/backingField/independentBackingFieldType.txt

@@ -0,0 +1,57 @@
+FILE fqName:<root> fileName:/independentBackingFieldType.kt
+  CLASS CLASS name:A modality:FINAL visibility:public superTypes:[kotlin.Any]
+    $this: VALUE_PARAMETER INSTANCE_RECEIVER name:<this> type:<root>.A
+    CONSTRUCTOR visibility:public <> () returnType:<root>.A [primary]
+      BLOCK_BODY
+        DELEGATING_CONSTRUCTOR_CALL 'public constructor <init> () [primary] declared in kotlin.Any'
+        INSTANCE_INITIALIZER_CALL classDescriptor='CLASS CLASS name:A modality:FINAL visibility:public superTypes:[kotlin.Any]'
+    PROPERTY name:it visibility:public modality:FINAL [var]
+      FIELD PROPERTY_BACKING_FIELD name:it type:kotlin.Double visibility:private
+        EXPRESSION_BODY
+          CONST Double type=kotlin.Double value=3.14
+      FUN name:<get-it> visibility:public modality:FINAL <> ($this:<root>.A) returnType:kotlin.Int
+        correspondingProperty: PROPERTY name:it visibility:public modality:FINAL [var]
+        $this: VALUE_PARAMETER name:<this> type:<root>.A
+        BLOCK_BODY
+          RETURN type=kotlin.Nothing from='public final fun <get-it> (): kotlin.Int declared in <root>.A'
+            CALL 'public open fun toInt (): kotlin.Int declared in kotlin.Double' type=kotlin.Int origin=null
+              $this: CALL 'public final fun plus (other: kotlin.Int): kotlin.Double [operator] declared in kotlin.Double' type=kotlin.Double origin=PLUS
+                $this: GET_FIELD 'FIELD PROPERTY_BACKING_FIELD name:it type:kotlin.Double visibility:private' type=kotlin.Double origin=GET_PROPERTY
+                  receiver: GET_VAR '<this>: <root>.A declared in <root>.A.<get-it>' type=<root>.A origin=null
+                other: CONST Int type=kotlin.Int value=10
+      FUN name:<set-it> visibility:public modality:FINAL <> ($this:<root>.A, value:kotlin.Int) returnType:kotlin.Unit
+        correspondingProperty: PROPERTY name:it visibility:public modality:FINAL [var]
+        $this: VALUE_PARAMETER name:<this> type:<root>.A
+        VALUE_PARAMETER name:value index:0 type:kotlin.Int
+        BLOCK_BODY
+          SET_FIELD 'FIELD PROPERTY_BACKING_FIELD name:it type:kotlin.Double visibility:private' type=kotlin.Unit origin=EQ
+            receiver: GET_VAR '<this>: <root>.A declared in <root>.A.<set-it>' type=<root>.A origin=null
+            value: CALL 'public open fun toDouble (): kotlin.Double declared in kotlin.Int' type=kotlin.Double origin=null
+              $this: CALL 'public final fun minus (other: kotlin.Int): kotlin.Int [operator] declared in kotlin.Int' type=kotlin.Int origin=MINUS
+                $this: GET_VAR 'value: kotlin.Int declared in <root>.A.<set-it>' type=kotlin.Int origin=null
+                other: CONST Int type=kotlin.Int value=10
+    FUN FAKE_OVERRIDE name:equals visibility:public modality:OPEN <> ($this:kotlin.Any, other:kotlin.Any?) returnType:kotlin.Boolean [fake_override,operator]
+      overridden:
+        public open fun equals (other: kotlin.Any?): kotlin.Boolean [operator] declared in kotlin.Any
+      $this: VALUE_PARAMETER name:<this> type:kotlin.Any
+      VALUE_PARAMETER name:other index:0 type:kotlin.Any?
+    FUN FAKE_OVERRIDE name:hashCode visibility:public modality:OPEN <> ($this:kotlin.Any) returnType:kotlin.Int [fake_override]
+      overridden:
+        public open fun hashCode (): kotlin.Int declared in kotlin.Any
+      $this: VALUE_PARAMETER name:<this> type:kotlin.Any
+    FUN FAKE_OVERRIDE name:toString visibility:public modality:OPEN <> ($this:kotlin.Any) returnType:kotlin.String [fake_override]
+      overridden:
+        public open fun toString (): kotlin.String declared in kotlin.Any
+      $this: VALUE_PARAMETER name:<this> type:kotlin.Any
+  FUN name:test visibility:public modality:FINAL <> () returnType:kotlin.Unit
+    BLOCK_BODY
+      VAR name:a type:<root>.A [val]
+        CONSTRUCTOR_CALL 'public constructor <init> () [primary] declared in <root>.A' type=<root>.A origin=null
+      VAR name:it type:kotlin.Int [val]
+        CALL 'public final fun and (other: kotlin.Int): kotlin.Int [operator] declared in kotlin.Int' type=kotlin.Int origin=null
+          $this: CALL 'public final fun <get-it> (): kotlin.Int declared in <root>.A' type=kotlin.Int origin=GET_PROPERTY
+            $this: CONSTRUCTOR_CALL 'public constructor <init> () [primary] declared in <root>.A' type=<root>.A origin=null
+          other: CONST Int type=kotlin.Int value=10
+      CALL 'public final fun <set-it> (value: kotlin.Int): kotlin.Unit declared in <root>.A' type=kotlin.Unit origin=EQ
+        $this: GET_VAR 'val a: <root>.A [val] declared in <root>.test' type=<root>.A origin=null
+        value: GET_VAR 'val it: kotlin.Int [val] declared in <root>.test' type=kotlin.Int origin=null

compiler/fir/fir2ir/testData/ir/irText/properties/backingField/propertyTypeNarrowing.kt

@@ -0,0 +1,15 @@
+// FIR_IDENTICAL
+class A {
+    val it: Number
+        field = 4
+
+    fun test() = it + 3
+
+    val p = 5
+        get() = field
+}
+
+fun test() {
+    val d = test()
+    val b = A().p + 2
+}

compiler/fir/fir2ir/testData/ir/irText/properties/backingField/propertyTypeNarrowing.kt.txt

@@ -0,0 +1,28 @@
+class A {
+  constructor() /* primary */ {
+    super/*Any*/()
+    /* <init>() */
+
+  }
+
+  val it: Int
+    field = 4
+    get
+
+  fun test(): Int {
+    return <this>.<get-it>().plus(other = 3)
+  }
+
+  val p: Int
+    field = 5
+    get(): Int {
+      return <this>.#p
+    }
+
+}
+
+fun test() {
+  val d: Unit = test()
+  val b: Int = A().<get-p>().plus(other = 2)
+}
+

compiler/fir/fir2ir/testData/ir/irText/properties/backingField/propertyTypeNarrowing.txt

@@ -0,0 +1,59 @@
+FILE fqName:<root> fileName:/propertyTypeNarrowing.kt
+  CLASS CLASS name:A modality:FINAL visibility:public superTypes:[kotlin.Any]
+    $this: VALUE_PARAMETER INSTANCE_RECEIVER name:<this> type:<root>.A
+    CONSTRUCTOR visibility:public <> () returnType:<root>.A [primary]
+      BLOCK_BODY
+        DELEGATING_CONSTRUCTOR_CALL 'public constructor <init> () [primary] declared in kotlin.Any'
+        INSTANCE_INITIALIZER_CALL classDescriptor='CLASS CLASS name:A modality:FINAL visibility:public superTypes:[kotlin.Any]'
+    PROPERTY name:it visibility:public modality:FINAL [val]
+      FIELD PROPERTY_BACKING_FIELD name:it type:kotlin.Int visibility:private [final]
+        EXPRESSION_BODY
+          CONST Int type=kotlin.Int value=4
+      FUN DEFAULT_PROPERTY_ACCESSOR name:<get-it> visibility:public modality:FINAL <> ($this:<root>.A) returnType:kotlin.Number
+        correspondingProperty: PROPERTY name:it visibility:public modality:FINAL [val]
+        $this: VALUE_PARAMETER name:<this> type:<root>.A
+        BLOCK_BODY
+          RETURN type=kotlin.Nothing from='public final fun <get-it> (): kotlin.Number declared in <root>.A'
+            GET_FIELD 'FIELD PROPERTY_BACKING_FIELD name:it type:kotlin.Int visibility:private [final]' type=kotlin.Number origin=null
+              receiver: GET_VAR '<this>: <root>.A declared in <root>.A.<get-it>' type=<root>.A origin=null
+    FUN name:test visibility:public modality:FINAL <> ($this:<root>.A) returnType:kotlin.Int
+      $this: VALUE_PARAMETER name:<this> type:<root>.A
+      BLOCK_BODY
+        RETURN type=kotlin.Nothing from='public final fun test (): kotlin.Int declared in <root>.A'
+          CALL 'public final fun plus (other: kotlin.Int): kotlin.Int [operator] declared in kotlin.Int' type=kotlin.Int origin=PLUS
+            $this: CALL 'public final fun <get-it> (): kotlin.Number declared in <root>.A' type=kotlin.Int origin=GET_PROPERTY
+              $this: GET_VAR '<this>: <root>.A declared in <root>.A.test' type=<root>.A origin=null
+            other: CONST Int type=kotlin.Int value=3
+    PROPERTY name:p visibility:public modality:FINAL [val]
+      FIELD PROPERTY_BACKING_FIELD name:p type:kotlin.Int visibility:private [final]
+        EXPRESSION_BODY
+          CONST Int type=kotlin.Int value=5
+      FUN name:<get-p> visibility:public modality:FINAL <> ($this:<root>.A) returnType:kotlin.Int
+        correspondingProperty: PROPERTY name:p visibility:public modality:FINAL [val]
+        $this: VALUE_PARAMETER name:<this> type:<root>.A
+        BLOCK_BODY
+          RETURN type=kotlin.Nothing from='public final fun <get-p> (): kotlin.Int declared in <root>.A'
+            GET_FIELD 'FIELD PROPERTY_BACKING_FIELD name:p type:kotlin.Int visibility:private [final]' type=kotlin.Int origin=GET_PROPERTY
+              receiver: GET_VAR '<this>: <root>.A declared in <root>.A.<get-p>' type=<root>.A origin=null
+    FUN FAKE_OVERRIDE name:equals visibility:public modality:OPEN <> ($this:kotlin.Any, other:kotlin.Any?) returnType:kotlin.Boolean [fake_override,operator]
+      overridden:
+        public open fun equals (other: kotlin.Any?): kotlin.Boolean [operator] declared in kotlin.Any
+      $this: VALUE_PARAMETER name:<this> type:kotlin.Any
+      VALUE_PARAMETER name:other index:0 type:kotlin.Any?
+    FUN FAKE_OVERRIDE name:hashCode visibility:public modality:OPEN <> ($this:kotlin.Any) returnType:kotlin.Int [fake_override]
+      overridden:
+        public open fun hashCode (): kotlin.Int declared in kotlin.Any
+      $this: VALUE_PARAMETER name:<this> type:kotlin.Any
+    FUN FAKE_OVERRIDE name:toString visibility:public modality:OPEN <> ($this:kotlin.Any) returnType:kotlin.String [fake_override]
+      overridden:
+        public open fun toString (): kotlin.String declared in kotlin.Any
+      $this: VALUE_PARAMETER name:<this> type:kotlin.Any
+  FUN name:test visibility:public modality:FINAL <> () returnType:kotlin.Unit
+    BLOCK_BODY
+      VAR name:d type:kotlin.Unit [val]
+        CALL 'public final fun test (): kotlin.Unit declared in <root>' type=kotlin.Unit origin=null
+      VAR name:b type:kotlin.Int [val]
+        CALL 'public final fun plus (other: kotlin.Int): kotlin.Int [operator] declared in kotlin.Int' type=kotlin.Int origin=PLUS
+          $this: CALL 'public final fun <get-p> (): kotlin.Int declared in <root>.A' type=kotlin.Int origin=GET_PROPERTY
+            $this: CONSTRUCTOR_CALL 'public constructor <init> () [primary] declared in <root>.A' type=<root>.A origin=null
+          other: CONST Int type=kotlin.Int value=2

compiler/fir/fir2ir/tests-gen/org/jetbrains/kotlin/test/runners/codegen/Fir2IrSpecificBytecodeListingTestGenerated.java

@@ -0,0 +1,33 @@
+/*
+ * Copyright 2010-2021 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.test.runners.codegen;
+
+import com.intellij.testFramework.TestDataPath;
+import org.jetbrains.kotlin.test.util.KtTestUtil;
+import org.jetbrains.kotlin.test.TargetBackend;
+import org.jetbrains.kotlin.test.TestMetadata;
+import org.junit.jupiter.api.Nested;
+import org.junit.jupiter.api.Test;
+
+import java.io.File;
+import java.util.regex.Pattern;
+
+/** This class is generated by {@link GenerateNewCompilerTests.kt}. DO NOT MODIFY MANUALLY */
+@SuppressWarnings("all")
+@TestMetadata("compiler/fir/fir2ir/testData/codegen/bytecodeListing")
+@TestDataPath("$PROJECT_ROOT")
+public class Fir2IrSpecificBytecodeListingTestGenerated extends AbstractFirBytecodeListingTest {
+    @Test
+    public void testAllFilesPresentInBytecodeListing() throws Exception {
+        KtTestUtil.assertAllTestsPresentByMetadataWithExcluded(this.getClass(), new File("compiler/fir/fir2ir/testData/codegen/bytecodeListing"), Pattern.compile("^(.+)\\.kt$"), null, TargetBackend.JVM_IR, true);
+    }
+
+    @Test
+    @TestMetadata("explicitBackingFieldsInJava.kt")
+    public void testExplicitBackingFieldsInJava() throws Exception {
+        runTest("compiler/fir/fir2ir/testData/codegen/bytecodeListing/explicitBackingFieldsInJava.kt");
+    }
+}

compiler/fir/fir2ir/tests-gen/org/jetbrains/kotlin/test/runners/codegen/FirSpecificBlackBoxCodegenTestGenerated.java

@@ -17,17 +17,142 @@ import java.util.regex.Pattern;
 
 /** This class is generated by {@link GenerateNewCompilerTests.kt}. DO NOT MODIFY MANUALLY */
 @SuppressWarnings("all")
-@TestMetadata("compiler/fir/fir2ir/testData/codegen/box")
-@TestDataPath("$PROJECT_ROOT")
 public class FirSpecificBlackBoxCodegenTestGenerated extends AbstractFirBlackBoxCodegenTest {
-    @Test
-    public void testAllFilesPresentInBox() throws Exception {
-        KtTestUtil.assertAllTestsPresentByMetadataWithExcluded(this.getClass(), new File("compiler/fir/fir2ir/testData/codegen/box"), Pattern.compile("^(.+)\\.kt$"), null, TargetBackend.JVM_IR, true);
+    @Nested
+    @TestMetadata("compiler/fir/fir2ir/testData/codegen/box")
+    @TestDataPath("$PROJECT_ROOT")
+    public class Box {
+        @Test
+        public void testAllFilesPresentInBox() throws Exception {
+            KtTestUtil.assertAllTestsPresentByMetadataWithExcluded(this.getClass(), new File("compiler/fir/fir2ir/testData/codegen/box"), Pattern.compile("^(.+)\\.kt$"), null, TargetBackend.JVM_IR, true);
+        }
+
+        @Test
+        @TestMetadata("sample.kt")
+        public void testSample() throws Exception {
+            runTest("compiler/fir/fir2ir/testData/codegen/box/sample.kt");
+        }
+
+        @Nested
+        @TestMetadata("compiler/fir/fir2ir/testData/codegen/box/properties")
+        @TestDataPath("$PROJECT_ROOT")
+        public class Properties {
+            @Test
+            public void testAllFilesPresentInProperties() throws Exception {
+                KtTestUtil.assertAllTestsPresentByMetadataWithExcluded(this.getClass(), new File("compiler/fir/fir2ir/testData/codegen/box/properties"), Pattern.compile("^(.+)\\.kt$"), null, TargetBackend.JVM_IR, true);
+            }
+
+            @Nested
+            @TestMetadata("compiler/fir/fir2ir/testData/codegen/box/properties/backingField")
+            @TestDataPath("$PROJECT_ROOT")
+            public class BackingField {
+                @Test
+                public void testAllFilesPresentInBackingField() throws Exception {
+                    KtTestUtil.assertAllTestsPresentByMetadataWithExcluded(this.getClass(), new File("compiler/fir/fir2ir/testData/codegen/box/properties/backingField"), Pattern.compile("^(.+)\\.kt$"), null, TargetBackend.JVM_IR, true);
+                }
+
+                @Test
+                @TestMetadata("backingFieldVisibility.kt")
+                public void testBackingFieldVisibility() throws Exception {
+                    runTest("compiler/fir/fir2ir/testData/codegen/box/properties/backingField/backingFieldVisibility.kt");
+                }
+
+                @Test
+                @TestMetadata("charSequenceWithBackingField1.kt")
+                public void testCharSequenceWithBackingField1() throws Exception {
+                    runTest("compiler/fir/fir2ir/testData/codegen/box/properties/backingField/charSequenceWithBackingField1.kt");
+                }
+
+                @Test
+                @TestMetadata("charSequenceWithBackingField2.kt")
+                public void testCharSequenceWithBackingField2() throws Exception {
+                    runTest("compiler/fir/fir2ir/testData/codegen/box/properties/backingField/charSequenceWithBackingField2.kt");
+                }
+
+                @Test
+                @TestMetadata("charSequenceWithBackingField3.kt")
+                public void testCharSequenceWithBackingField3() throws Exception {
+                    runTest("compiler/fir/fir2ir/testData/codegen/box/properties/backingField/charSequenceWithBackingField3.kt");
+                }
+
+                @Test
+                @TestMetadata("charSequenceWithBackingField4.kt")
+                public void testCharSequenceWithBackingField4() throws Exception {
+                    runTest("compiler/fir/fir2ir/testData/codegen/box/properties/backingField/charSequenceWithBackingField4.kt");
+                }
+
+                @Test
+                @TestMetadata("charSequenceWithBackingField5.kt")
+                public void testCharSequenceWithBackingField5() throws Exception {
+                    runTest("compiler/fir/fir2ir/testData/codegen/box/properties/backingField/charSequenceWithBackingField5.kt");
+                }
+
+                @Test
+                @TestMetadata("explicitBackingFieldInAnonymous.kt")
+                public void testExplicitBackingFieldInAnonymous() throws Exception {
+                    runTest("compiler/fir/fir2ir/testData/codegen/box/properties/backingField/explicitBackingFieldInAnonymous.kt");
+                }
+
+                @Test
+                @TestMetadata("getterReturnTypeWithBackingField.kt")
+                public void testGetterReturnTypeWithBackingField() throws Exception {
+                    runTest("compiler/fir/fir2ir/testData/codegen/box/properties/backingField/getterReturnTypeWithBackingField.kt");
+                }
+
+                @Test
+                @TestMetadata("independentBackingFieldType.kt")
+                public void testIndependentBackingFieldType() throws Exception {
+                    runTest("compiler/fir/fir2ir/testData/codegen/box/properties/backingField/independentBackingFieldType.kt");
+                }
+
+                @Test
+                @TestMetadata("lateinitBackingFields.kt")
+                public void testLateinitBackingFields() throws Exception {
+                    runTest("compiler/fir/fir2ir/testData/codegen/box/properties/backingField/lateinitBackingFields.kt");
+                }
+
+                @Test
+                @TestMetadata("overriddenPropertiesWithExplicitBackingFields.kt")
+                public void testOverriddenPropertiesWithExplicitBackingFields() throws Exception {
+                    runTest("compiler/fir/fir2ir/testData/codegen/box/properties/backingField/overriddenPropertiesWithExplicitBackingFields.kt");
+                }
+            }
+        }
     }
 
-    @Test
-    @TestMetadata("sample.kt")
-    public void testSample() throws Exception {
-        runTest("compiler/fir/fir2ir/testData/codegen/box/sample.kt");
+    @Nested
+    @TestMetadata("compiler/fir/fir2ir/testData/codegen/boxWithStdLib")
+    @TestDataPath("$PROJECT_ROOT")
+    public class BoxWithStdLib {
+        @Test
+        public void testAllFilesPresentInBoxWithStdLib() throws Exception {
+            KtTestUtil.assertAllTestsPresentByMetadataWithExcluded(this.getClass(), new File("compiler/fir/fir2ir/testData/codegen/boxWithStdLib"), Pattern.compile("^(.+)\\.kt$"), null, TargetBackend.JVM_IR, true);
+        }
+
+        @Nested
+        @TestMetadata("compiler/fir/fir2ir/testData/codegen/boxWithStdLib/properties")
+        @TestDataPath("$PROJECT_ROOT")
+        public class Properties {
+            @Test
+            public void testAllFilesPresentInProperties() throws Exception {
+                KtTestUtil.assertAllTestsPresentByMetadataWithExcluded(this.getClass(), new File("compiler/fir/fir2ir/testData/codegen/boxWithStdLib/properties"), Pattern.compile("^(.+)\\.kt$"), null, TargetBackend.JVM_IR, true);
+            }
+
+            @Nested
+            @TestMetadata("compiler/fir/fir2ir/testData/codegen/boxWithStdLib/properties/backingField")
+            @TestDataPath("$PROJECT_ROOT")
+            public class BackingField {
+                @Test
+                public void testAllFilesPresentInBackingField() throws Exception {
+                    KtTestUtil.assertAllTestsPresentByMetadataWithExcluded(this.getClass(), new File("compiler/fir/fir2ir/testData/codegen/boxWithStdLib/properties/backingField"), Pattern.compile("^(.+)\\.kt$"), null, TargetBackend.JVM_IR, true);
+                }
+
+                @Test
+                @TestMetadata("backingFieldWithSmartTypeParameters.kt")
+                public void testBackingFieldWithSmartTypeParameters() throws Exception {
+                    runTest("compiler/fir/fir2ir/testData/codegen/boxWithStdLib/properties/backingField/backingFieldWithSmartTypeParameters.kt");
+                }
+            }
+        }
     }
 }

compiler/fir/fir2ir/tests-gen/org/jetbrains/kotlin/test/runners/ir/Fir2IrSpecificTextTestGenerated.java

@@ -30,4 +30,48 @@ public class Fir2IrSpecificTextTestGenerated extends AbstractFir2IrTextTest {
     public void testSample() throws Exception {
         runTest("compiler/fir/fir2ir/testData/ir/irText/sample.kt");
     }
+
+    @Nested
+    @TestMetadata("compiler/fir/fir2ir/testData/ir/irText/properties")
+    @TestDataPath("$PROJECT_ROOT")
+    public class Properties {
+        @Test
+        public void testAllFilesPresentInProperties() throws Exception {
+            KtTestUtil.assertAllTestsPresentByMetadataWithExcluded(this.getClass(), new File("compiler/fir/fir2ir/testData/ir/irText/properties"), Pattern.compile("^(.+)\\.kt$"), null, TargetBackend.JVM_IR, true);
+        }
+
+        @Nested
+        @TestMetadata("compiler/fir/fir2ir/testData/ir/irText/properties/backingField")
+        @TestDataPath("$PROJECT_ROOT")
+        public class BackingField {
+            @Test
+            public void testAllFilesPresentInBackingField() throws Exception {
+                KtTestUtil.assertAllTestsPresentByMetadataWithExcluded(this.getClass(), new File("compiler/fir/fir2ir/testData/ir/irText/properties/backingField"), Pattern.compile("^(.+)\\.kt$"), null, TargetBackend.JVM_IR, true);
+            }
+
+            @Test
+            @TestMetadata("backingFieldVisibility.kt")
+            public void testBackingFieldVisibility() throws Exception {
+                runTest("compiler/fir/fir2ir/testData/ir/irText/properties/backingField/backingFieldVisibility.kt");
+            }
+
+            @Test
+            @TestMetadata("explicitBackingFieldType.kt")
+            public void testExplicitBackingFieldType() throws Exception {
+                runTest("compiler/fir/fir2ir/testData/ir/irText/properties/backingField/explicitBackingFieldType.kt");
+            }
+
+            @Test
+            @TestMetadata("independentBackingFieldType.kt")
+            public void testIndependentBackingFieldType() throws Exception {
+                runTest("compiler/fir/fir2ir/testData/ir/irText/properties/backingField/independentBackingFieldType.kt");
+            }
+
+            @Test
+            @TestMetadata("propertyTypeNarrowing.kt")
+            public void testPropertyTypeNarrowing() throws Exception {
+                runTest("compiler/fir/fir2ir/testData/ir/irText/properties/backingField/propertyTypeNarrowing.kt");
+            }
+        }
+    }
 }

compiler/testData/diagnostics/tests/properties/backingField/trivialExplicitBackingFIeld.fir.kt

@@ -0,0 +1,4 @@
+class A {
+    val number: Number
+        field = 1
+}

compiler/testData/diagnostics/tests/properties/backingField/trivialExplicitBackingFIeld.kt

@@ -0,0 +1,4 @@
+class A {
+    <!MUST_BE_INITIALIZED_OR_BE_ABSTRACT!>val number: Number<!>
+        <!EXPLICIT_BACKING_FIELDS_UNSUPPORTED!>field = 1<!>
+}

compiler/testData/diagnostics/tests/properties/backingField/trivialExplicitBackingFIeld.txt

@@ -0,0 +1,9 @@
+package
+
+public final class A {
+    public constructor A()
+    public final val number: kotlin.Number
+    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 open override /*1*/ /*fake_override*/ fun toString(): kotlin.String
+}

compiler/testData/psi/propertyBackingField/explicitBackingField.txt

@@ -197,17 +197,22 @@ KtFile: explicitBackingField.kt
     PsiWhiteSpace('\n    ')
     BACKING_FIELD
       PsiElement(field)('field')
-      PsiWhiteSpace(' ')
-      BLOCK
-        PsiElement(LBRACE)('{')
-        PsiWhiteSpace('\n        ')
-        RETURN
-          PsiElement(return)('return')
-          PsiWhiteSpace(' ')
-          INTEGER_CONSTANT
-            PsiElement(INTEGER_LITERAL)('10')
-        PsiWhiteSpace('\n    ')
-        PsiElement(RBRACE)('}')
+    PsiErrorElement:Property getter or setter expected
+      <empty list>
+  PsiWhiteSpace(' ')
+  FUN
+    PsiErrorElement:Expecting a top level declaration
+      <empty list>
+    BLOCK
+      PsiElement(LBRACE)('{')
+      PsiWhiteSpace('\n        ')
+      RETURN
+        PsiElement(return)('return')
+        PsiWhiteSpace(' ')
+        INTEGER_CONSTANT
+          PsiElement(INTEGER_LITERAL)('10')
+      PsiWhiteSpace('\n    ')
+      PsiElement(RBRACE)('}')
   PsiWhiteSpace('\n\n')
   PROPERTY
     PsiElement(val)('val')

compiler/tests-common-new/tests-gen/org/jetbrains/kotlin/test/runners/DiagnosticTestGenerated.java

@@ -22491,6 +22491,22 @@ public class DiagnosticTestGenerated extends AbstractDiagnosticTest {
                 runTest("compiler/testData/diagnostics/tests/properties/lateinitOnTopLevel.kt");
             }
 
+            @Nested
+            @TestMetadata("compiler/testData/diagnostics/tests/properties/backingField")
+            @TestDataPath("$PROJECT_ROOT")
+            public class BackingField {
+                @Test
+                public void testAllFilesPresentInBackingField() throws Exception {
+                    KtTestUtil.assertAllTestsPresentByMetadataWithExcluded(this.getClass(), new File("compiler/testData/diagnostics/tests/properties/backingField"), Pattern.compile("^(.*)\\.kts?$"), Pattern.compile("^(.+)\\.fir\\.kts?$"), true);
+                }
+
+                @Test
+                @TestMetadata("trivialExplicitBackingFIeld.kt")
+                public void testTrivialExplicitBackingFIeld() throws Exception {
+                    runTest("compiler/testData/diagnostics/tests/properties/backingField/trivialExplicitBackingFIeld.kt");
+                }
+            }
+
             @Nested
             @TestMetadata("compiler/testData/diagnostics/tests/properties/inferenceFromGetters")
             @TestDataPath("$PROJECT_ROOT")

compiler/tests-common-new/tests/org/jetbrains/kotlin/test/runners/codegen/AbstractFirBlackBoxCodegenTest.kt

@@ -12,6 +12,7 @@ import org.jetbrains.kotlin.test.backend.ir.JvmIrBackendFacade
 import org.jetbrains.kotlin.test.builders.TestConfigurationBuilder
 import org.jetbrains.kotlin.test.builders.configureFirHandlersStep
 import org.jetbrains.kotlin.test.directives.JvmEnvironmentConfigurationDirectives.USE_PSI_CLASS_FILES_READING
+import org.jetbrains.kotlin.test.directives.JvmEnvironmentConfigurationDirectives.WITH_STDLIB
 import org.jetbrains.kotlin.test.frontend.fir.Fir2IrResultsConverter
 import org.jetbrains.kotlin.test.frontend.fir.FirFrontendFacade
 import org.jetbrains.kotlin.test.frontend.fir.FirMetaInfoDiffSuppressor
@@ -43,6 +44,12 @@ open class AbstractFirBlackBoxCodegenTest : AbstractJvmBlackBoxCodegenTestBase<F
                 -USE_PSI_CLASS_FILES_READING
             }
 
+            forTestsMatching("*WithStdLib/*") {
+                defaultDirectives {
+                    +WITH_STDLIB
+                }
+            }
+
             configureFirHandlersStep {
                 useHandlers(
                     ::FirDumpHandler,

compiler/tests-for-compiler-generator/tests/org/jetbrains/kotlin/test/generators/GenerateJUnit5CompilerTests.kt

@@ -203,6 +203,7 @@ fun generateJUnit5CompilerTests(args: Array<String>) {
                 suiteTestClassName = "FirSpecificBlackBoxCodegenTestGenerated"
             ) {
                 model("codegen/box")
+                model("codegen/boxWithStdLib")
             }
 
             testClass<AbstractFir2IrTextTest>(

idea/idea-frontend-fir/idea-fir-low-level-api/tests/org/jetbrains/kotlin/idea/fir/low/level/api/diagnostic/compiler/based/DiagnosisCompilerFirTestdataTestGenerated.java

@@ -5532,6 +5532,104 @@ public class DiagnosisCompilerFirTestdataTestGenerated extends AbstractDiagnosis
             }
         }
 
+        @Nested
+        @TestMetadata("compiler/fir/analysis-tests/testData/resolveWithStdlib/properties")
+        @TestDataPath("$PROJECT_ROOT")
+        public class Properties {
+            @Test
+            public void testAllFilesPresentInProperties() throws Exception {
+                KtTestUtil.assertAllTestsPresentByMetadataWithExcluded(this.getClass(), new File("compiler/fir/analysis-tests/testData/resolveWithStdlib/properties"), Pattern.compile("^([^.]+)\\.kt$"), null, true);
+            }
+
+            @Nested
+            @TestMetadata("compiler/fir/analysis-tests/testData/resolveWithStdlib/properties/backingField")
+            @TestDataPath("$PROJECT_ROOT")
+            public class BackingField {
+                @Test
+                public void testAllFilesPresentInBackingField() throws Exception {
+                    KtTestUtil.assertAllTestsPresentByMetadataWithExcluded(this.getClass(), new File("compiler/fir/analysis-tests/testData/resolveWithStdlib/properties/backingField"), Pattern.compile("^([^.]+)\\.kt$"), null, true);
+                }
+
+                @Test
+                @TestMetadata("backingFieldModifiers.kt")
+                public void testBackingFieldModifiers() throws Exception {
+                    runTest("compiler/fir/analysis-tests/testData/resolveWithStdlib/properties/backingField/backingFieldModifiers.kt");
+                }
+
+                @Test
+                @TestMetadata("backingFieldVisibility.kt")
+                public void testBackingFieldVisibility() throws Exception {
+                    runTest("compiler/fir/analysis-tests/testData/resolveWithStdlib/properties/backingField/backingFieldVisibility.kt");
+                }
+
+                @Test
+                @TestMetadata("backingFieldWithSmartTypeParameters.kt")
+                public void testBackingFieldWithSmartTypeParameters() throws Exception {
+                    runTest("compiler/fir/analysis-tests/testData/resolveWithStdlib/properties/backingField/backingFieldWithSmartTypeParameters.kt");
+                }
+
+                @Test
+                @TestMetadata("explicitBackingFieldInInterface.kt")
+                public void testExplicitBackingFieldInInterface() throws Exception {
+                    runTest("compiler/fir/analysis-tests/testData/resolveWithStdlib/properties/backingField/explicitBackingFieldInInterface.kt");
+                }
+
+                @Test
+                @TestMetadata("explicitBackingFieldType.kt")
+                public void testExplicitBackingFieldType() throws Exception {
+                    runTest("compiler/fir/analysis-tests/testData/resolveWithStdlib/properties/backingField/explicitBackingFieldType.kt");
+                }
+
+                @Test
+                @TestMetadata("explicitBackingFieldsWithDelegates.kt")
+                public void testExplicitBackingFieldsWithDelegates() throws Exception {
+                    runTest("compiler/fir/analysis-tests/testData/resolveWithStdlib/properties/backingField/explicitBackingFieldsWithDelegates.kt");
+                }
+
+                @Test
+                @TestMetadata("filePrivateBackingFieldAccess.kt")
+                public void testFilePrivateBackingFieldAccess() throws Exception {
+                    runTest("compiler/fir/analysis-tests/testData/resolveWithStdlib/properties/backingField/filePrivateBackingFieldAccess.kt");
+                }
+
+                @Test
+                @TestMetadata("lateinitBackingFields.kt")
+                public void testLateinitBackingFields() throws Exception {
+                    runTest("compiler/fir/analysis-tests/testData/resolveWithStdlib/properties/backingField/lateinitBackingFields.kt");
+                }
+
+                @Test
+                @TestMetadata("localVariablesWithBackingFields.kt")
+                public void testLocalVariablesWithBackingFields() throws Exception {
+                    runTest("compiler/fir/analysis-tests/testData/resolveWithStdlib/properties/backingField/localVariablesWithBackingFields.kt");
+                }
+
+                @Test
+                @TestMetadata("overriddenPropertiesWithExplicitBackingFields.kt")
+                public void testOverriddenPropertiesWithExplicitBackingFields() throws Exception {
+                    runTest("compiler/fir/analysis-tests/testData/resolveWithStdlib/properties/backingField/overriddenPropertiesWithExplicitBackingFields.kt");
+                }
+
+                @Test
+                @TestMetadata("propertyTypeNarrowing.kt")
+                public void testPropertyTypeNarrowing() throws Exception {
+                    runTest("compiler/fir/analysis-tests/testData/resolveWithStdlib/properties/backingField/propertyTypeNarrowing.kt");
+                }
+
+                @Test
+                @TestMetadata("randomWeirdBackingFields.kt")
+                public void testRandomWeirdBackingFields() throws Exception {
+                    runTest("compiler/fir/analysis-tests/testData/resolveWithStdlib/properties/backingField/randomWeirdBackingFields.kt");
+                }
+
+                @Test
+                @TestMetadata("redundantExplicitBackingField.kt")
+                public void testRedundantExplicitBackingField() throws Exception {
+                    runTest("compiler/fir/analysis-tests/testData/resolveWithStdlib/properties/backingField/redundantExplicitBackingField.kt");
+                }
+            }
+        }
+
         @Nested
         @TestMetadata("compiler/fir/analysis-tests/testData/resolveWithStdlib/reinitializations")
         @TestDataPath("$PROJECT_ROOT")

idea/idea-frontend-fir/idea-fir-low-level-api/tests/org/jetbrains/kotlin/idea/fir/low/level/api/diagnostic/compiler/based/DiagnosisCompilerTestFE10TestdataTestGenerated.java

@@ -22485,6 +22485,22 @@ public class DiagnosisCompilerTestFE10TestdataTestGenerated extends AbstractDiag
                 runTest("compiler/testData/diagnostics/tests/properties/lateinitOnTopLevel.kt");
             }
 
+            @Nested
+            @TestMetadata("compiler/testData/diagnostics/tests/properties/backingField")
+            @TestDataPath("$PROJECT_ROOT")
+            public class BackingField {
+                @Test
+                public void testAllFilesPresentInBackingField() throws Exception {
+                    KtTestUtil.assertAllTestsPresentByMetadataWithExcluded(this.getClass(), new File("compiler/testData/diagnostics/tests/properties/backingField"), Pattern.compile("^(.+)\\.kt$"), Pattern.compile("^(.+)\\.fir\\.kts?$"), true);
+                }
+
+                @Test
+                @TestMetadata("trivialExplicitBackingFIeld.kt")
+                public void testTrivialExplicitBackingFIeld() throws Exception {
+                    runTest("compiler/testData/diagnostics/tests/properties/backingField/trivialExplicitBackingFIeld.kt");
+                }
+            }
+
             @Nested
             @TestMetadata("compiler/testData/diagnostics/tests/properties/inferenceFromGetters")
             @TestDataPath("$PROJECT_ROOT")