"field": synthetic variable creation in accessors, codegen changed accordingly, a set of tests, relevant code fix (j2k)

compiler/testData/diagnostics/tests/backingField/FieldAsProperty.kt

@@ -0,0 +1,9 @@
+class My(val field: Int) {
+    // Backing field, initializer
+    val second: Int = 0
+        get() = field
+
+    // No backing field, no initializer
+    val third: Int
+        get() = this.field
+}

compiler/testData/diagnostics/tests/backingField/FieldAsProperty.txt

@@ -0,0 +1,11 @@
+package
+
+public final class My {
+    public constructor My(/*0*/ field: kotlin.Int)
+    public final val field: kotlin.Int
+    public final val second: kotlin.Int = 0
+    public final val third: kotlin.Int
+    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/diagnostics/tests/backingField/FieldDerived.kt

@@ -0,0 +1,18 @@
+open class Base {
+    open val x: Int = 1
+        get() = field - 1
+}
+
+class Other: Base() {
+    override val x = 2
+}
+
+class Another: Base() {
+    override val x = 3
+        get() = field + 1
+}
+
+class NoBackingField: Base() {
+    override val x: Int
+        get() = 5
+}

compiler/testData/diagnostics/tests/backingField/FieldDerived.txt

@@ -0,0 +1,33 @@
+package
+
+public final class Another : Base {
+    public constructor Another()
+    public open override /*1*/ val x: kotlin.Int = 3
+    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
+}
+
+public open class Base {
+    public constructor Base()
+    public open val x: kotlin.Int = 1
+    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
+}
+
+public final class NoBackingField : Base {
+    public constructor NoBackingField()
+    public open override /*1*/ val x: kotlin.Int
+    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
+}
+
+public final class Other : Base {
+    public constructor Other()
+    public open override /*1*/ val x: kotlin.Int = 2
+    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/diagnostics/tests/backingField/FieldInInterface.kt

@@ -0,0 +1,4 @@
+interface My {
+    <!BACKING_FIELD_IN_TRAIT!>val x: Int<!> = <!PROPERTY_INITIALIZER_IN_TRAIT!>0<!>
+        get() = field
+}

compiler/testData/diagnostics/tests/backingField/FieldInInterface.txt

@@ -0,0 +1,8 @@
+package
+
+public interface My {
+    public open val x: kotlin.Int = 0
+    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/diagnostics/tests/backingField/FieldInLocal.kt

@@ -0,0 +1,11 @@
+// !DIAGNOSTICS: -UNUSED_VARIABLE
+fun foo() {
+    open class Local {
+        val my: Int = 2
+            get() = field
+    }
+    val your = object: Local() {
+        val your: Int = 3
+            get() = field
+    }
+}

compiler/testData/diagnostics/tests/backingField/FieldInLocal.txt

@@ -0,0 +1,3 @@
+package
+
+public fun foo(): kotlin.Unit

compiler/testData/diagnostics/tests/backingField/FieldOnVal.kt

@@ -0,0 +1,2 @@
+val my: Int = 21
+    get() = field * 2

compiler/testData/diagnostics/tests/backingField/FieldOnVal.txt

@@ -0,0 +1,3 @@
+package
+
+public val my: kotlin.Int = 21

compiler/testData/diagnostics/tests/backingField/FieldOnVar.kt

@@ -0,0 +1,5 @@
+var my: Int = 0
+    get() = -field
+    set(arg) {
+        field = arg
+    }

compiler/testData/diagnostics/tests/backingField/FieldOnVar.txt

@@ -0,0 +1,3 @@
+package
+
+public var my: kotlin.Int

compiler/testData/diagnostics/tests/backingField/FieldShadow.kt

@@ -0,0 +1,8 @@
+class My {
+    // No initialization needed because no backing field
+    val two: Int
+        get() {
+            val <!NAME_SHADOWING!>field<!> = 2
+            return field
+        }
+}

compiler/testData/diagnostics/tests/backingField/FieldShadow.txt

@@ -0,0 +1,9 @@
+package
+
+public final class My {
+    public constructor My()
+    public final val two: kotlin.Int
+    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
+}