K2: add checker detecting protected Java field shadowed by a property

compiler/testData/diagnostics/tests/javaFieldKotlinPropertyJavaFieldInPackagePrivate.fir.kt

@@ -0,0 +1,27 @@
+// FILE: A.java
+
+package base;
+
+class A {
+    public String f = "OK";
+}
+
+// FILE: B.kt
+
+package base
+
+open class B : <!EXPOSED_SUPER_CLASS!>A<!>() {
+    private val f = "FAIL"
+}
+
+// FILE: C.java
+
+import base.B;
+
+public class C extends B {}
+
+// FILE: test.kt
+
+fun box(): String {
+    return C().f
+}

compiler/testData/diagnostics/tests/javaFieldKotlinPropertyJavaFieldInPackagePrivate.kt

@@ -0,0 +1,27 @@
+// FILE: A.java
+
+package base;
+
+class A {
+    public String f = "OK";
+}
+
+// FILE: B.kt
+
+package base
+
+open class B : <!EXPOSED_SUPER_CLASS!>A()<!> {
+    private val f = "FAIL"
+}
+
+// FILE: C.java
+
+import base.B;
+
+public class C extends B {}
+
+// FILE: test.kt
+
+fun box(): String {
+    return C().f
+}

compiler/testData/diagnostics/tests/javaFieldKotlinPropertyJavaFieldInPackagePrivate.txt

@@ -0,0 +1,32 @@
+package
+
+public fun box(): kotlin.String
+
+public open class C : base.B {
+    public constructor C()
+    invisible_fake final override /*1*/ /*fake_override*/ val f: kotlin.String
+    public final override /*1*/ /*fake_override*/ var f: kotlin.String!
+    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
+}
+
+package base {
+
+    public/*package*/ open class A {
+        public/*package*/ constructor A()
+        public final var f: kotlin.String!
+        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 B : base.A {
+        public constructor B()
+        private final val f: kotlin.String = "FAIL"
+        public final override /*1*/ /*fake_override*/ var f: kotlin.String!
+        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/javaFieldKotlinPropertyJavaPackagePrivateField.fir.kt

@@ -0,0 +1,27 @@
+// FILE: A.java
+
+package base;
+
+public class A {
+    String f = "OK";
+}
+
+// FILE: B.kt
+
+package base
+
+open class B : A() {
+    private val f = "FAIL"
+}
+
+// FILE: C.java
+
+import base.B;
+
+public class C extends B {}
+
+// FILE: test.kt
+
+fun box(): String {
+    return C().<!INVISIBLE_REFERENCE!>f<!>
+}

compiler/testData/diagnostics/tests/javaFieldKotlinPropertyJavaPackagePrivateField.kt

@@ -0,0 +1,27 @@
+// FILE: A.java
+
+package base;
+
+public class A {
+    String f = "OK";
+}
+
+// FILE: B.kt
+
+package base
+
+open class B : A() {
+    private val f = "FAIL"
+}
+
+// FILE: C.java
+
+import base.B;
+
+public class C extends B {}
+
+// FILE: test.kt
+
+fun box(): String {
+    return C().<!INVISIBLE_MEMBER!>f<!>
+}

compiler/testData/diagnostics/tests/javaFieldKotlinPropertyJavaPackagePrivateField.txt

@@ -0,0 +1,32 @@
+package
+
+public fun box(): kotlin.String
+
+public open class C : base.B {
+    public constructor C()
+    invisible_fake final override /*1*/ /*fake_override*/ val f: kotlin.String
+    invisible_fake final override /*1*/ /*fake_override*/ var f: kotlin.String!
+    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
+}
+
+package base {
+
+    public open class A {
+        public constructor A()
+        public/*package*/ final var f: kotlin.String!
+        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 B : base.A {
+        public constructor B()
+        private final val f: kotlin.String = "FAIL"
+        public/*package*/ final override /*1*/ /*fake_override*/ var f: kotlin.String!
+        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/javaProtectedFieldAndKotlinInvisiblePropertyReference.fir.kt

@@ -0,0 +1,94 @@
+// FILE: BaseJava.java
+
+package base;
+
+public class BaseJava {
+    protected String a = "TARGET";
+
+    String b = "";
+}
+
+class DerivedJava extends BaseKotlin {
+    protected String a = "";
+}
+
+// FILE: Base.kt
+
+package base
+
+abstract class BaseKotlin
+
+open class Intermediate : BaseJava() {
+    private val a = ""
+}
+
+class Derived : Intermediate() {
+    fun foo() = this::a // Same package
+}
+
+private class DerivedFromDerivedJava : DerivedJava() {
+    fun foo() = this::a // Property class is a subclass of the field class
+}
+
+// FILE: Derived.kt
+
+package derived
+
+import base.BaseJava
+
+open class Intermediate : BaseJava() {
+    private val a = ""
+
+    private val b = ""
+}
+
+open class IntermediateWithoutField : BaseJava() {
+    private val a get() = ""
+}
+
+open class IntermediatePublic : BaseJava() {
+    val a = ""
+}
+
+class Derived : Intermediate() {
+    // This should be the first erroneous place (only in K2)
+    fun foo() = this::<!JAVA_SHADOWED_PROTECTED_FIELD_REFERENCE!>a<!>
+
+    fun bar() = a // Non-reference
+
+    fun baz() = this::<!UNRESOLVED_REFERENCE!>b<!> // Non-protected
+}
+
+typealias Alias = Intermediate
+
+class DerivedAlias : Alias() {
+    // This should be the second erroneous place (only in K2)
+    fun foo() = this::<!JAVA_SHADOWED_PROTECTED_FIELD_REFERENCE!>a<!>
+}
+
+fun local() {
+    open class LocalIntermediate : BaseJava() {
+        private val a = ""
+    }
+
+    class LocalDerived : LocalIntermediate() {
+        // This should be the third and the last erroneous place (only in K2)
+        fun foo() = this::<!JAVA_SHADOWED_PROTECTED_FIELD_REFERENCE!>a<!>
+    }
+}
+
+class DerivedWithoutBackingField : IntermediateWithoutField() {
+    fun foo() = this::a // No shadowing backing field
+}
+
+class DerivedPublic : IntermediatePublic() {
+    fun foo() = this::a // Visible property
+}
+
+class DirectlyDerived : BaseJava() {
+    fun foo() = this::a // No property at all
+}
+
+fun test(d: Derived) {
+    d::<!UNRESOLVED_REFERENCE!>a<!> // Field is also invisible
+}

compiler/testData/diagnostics/tests/javaProtectedFieldAndKotlinInvisiblePropertyReference.kt

@@ -0,0 +1,94 @@
+// FILE: BaseJava.java
+
+package base;
+
+public class BaseJava {
+    protected String a = "TARGET";
+
+    String b = "";
+}
+
+class DerivedJava extends BaseKotlin {
+    protected String a = "";
+}
+
+// FILE: Base.kt
+
+package base
+
+abstract class BaseKotlin
+
+open class Intermediate : BaseJava() {
+    private val a = ""
+}
+
+class Derived : Intermediate() {
+    fun foo() = this::a // Same package
+}
+
+private class DerivedFromDerivedJava : DerivedJava() {
+    fun foo() = this::a // Property class is a subclass of the field class
+}
+
+// FILE: Derived.kt
+
+package derived
+
+import base.BaseJava
+
+open class Intermediate : BaseJava() {
+    private val a = ""
+
+    private val b = ""
+}
+
+open class IntermediateWithoutField : BaseJava() {
+    private val a get() = ""
+}
+
+open class IntermediatePublic : BaseJava() {
+    val a = ""
+}
+
+class Derived : Intermediate() {
+    // This should be the first erroneous place (only in K2)
+    fun foo() = this::a
+
+    fun bar() = a // Non-reference
+
+    fun baz() = this::<!INVISIBLE_MEMBER!>b<!> // Non-protected
+}
+
+typealias Alias = Intermediate
+
+class DerivedAlias : Alias() {
+    // This should be the second erroneous place (only in K2)
+    fun foo() = this::a
+}
+
+fun local() {
+    open class LocalIntermediate : BaseJava() {
+        private val a = ""
+    }
+
+    class LocalDerived : LocalIntermediate() {
+        // This should be the third and the last erroneous place (only in K2)
+        fun foo() = this::a
+    }
+}
+
+class DerivedWithoutBackingField : IntermediateWithoutField() {
+    fun foo() = this::a // No shadowing backing field
+}
+
+class DerivedPublic : IntermediatePublic() {
+    fun foo() = this::a // Visible property
+}
+
+class DirectlyDerived : BaseJava() {
+    fun foo() = this::a // No property at all
+}
+
+fun test(d: Derived) {
+    d::<!INVISIBLE_MEMBER!>a<!> // Field is also invisible
+}

compiler/testData/diagnostics/tests/javaProtectedFieldAndKotlinInvisiblePropertyReference.txt

@@ -0,0 +1,153 @@
+package
+
+package base {
+
+    public open class BaseJava {
+        public constructor BaseJava()
+        protected/*protected and package*/ final var a: kotlin.String!
+        public/*package*/ final var b: kotlin.String!
+        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 abstract class BaseKotlin {
+        public constructor BaseKotlin()
+        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 Derived : base.Intermediate {
+        public constructor Derived()
+        invisible_fake final override /*1*/ /*fake_override*/ val a: kotlin.String
+        protected/*protected and package*/ final override /*1*/ /*fake_override*/ var a: kotlin.String!
+        public/*package*/ final override /*1*/ /*fake_override*/ var b: kotlin.String!
+        public open override /*1*/ /*fake_override*/ fun equals(/*0*/ other: kotlin.Any?): kotlin.Boolean
+        public final fun foo(): kotlin.reflect.KMutableProperty0<kotlin.String!>
+        public open override /*1*/ /*fake_override*/ fun hashCode(): kotlin.Int
+        public open override /*1*/ /*fake_override*/ fun toString(): kotlin.String
+    }
+
+    private final class DerivedFromDerivedJava : base.DerivedJava {
+        public constructor DerivedFromDerivedJava()
+        protected/*protected and package*/ final override /*1*/ /*fake_override*/ var a: kotlin.String!
+        public open override /*1*/ /*fake_override*/ fun equals(/*0*/ other: kotlin.Any?): kotlin.Boolean
+        public final fun foo(): kotlin.reflect.KMutableProperty0<kotlin.String!>
+        public open override /*1*/ /*fake_override*/ fun hashCode(): kotlin.Int
+        public open override /*1*/ /*fake_override*/ fun toString(): kotlin.String
+    }
+
+    public/*package*/ open class DerivedJava : base.BaseKotlin {
+        public/*package*/ constructor DerivedJava()
+        protected/*protected and package*/ final var a: kotlin.String!
+        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 Intermediate : base.BaseJava {
+        public constructor Intermediate()
+        private final val a: kotlin.String = ""
+        protected/*protected and package*/ final override /*1*/ /*fake_override*/ var a: kotlin.String!
+        public/*package*/ final override /*1*/ /*fake_override*/ var b: kotlin.String!
+        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
+    }
+}
+
+package derived {
+    public fun local(): kotlin.Unit
+    public fun test(/*0*/ d: derived.Derived): kotlin.Unit
+
+    public final class Derived : derived.Intermediate {
+        public constructor Derived()
+        invisible_fake final override /*1*/ /*fake_override*/ val a: kotlin.String
+        protected/*protected and package*/ final override /*1*/ /*fake_override*/ var a: kotlin.String!
+        invisible_fake final override /*1*/ /*fake_override*/ val b: kotlin.String
+        invisible_fake final override /*1*/ /*fake_override*/ var b: kotlin.String!
+        public final fun bar(): kotlin.String!
+        public final fun baz(): kotlin.reflect.KMutableProperty0<kotlin.String!>
+        public open override /*1*/ /*fake_override*/ fun equals(/*0*/ other: kotlin.Any?): kotlin.Boolean
+        public final fun foo(): kotlin.reflect.KMutableProperty0<kotlin.String!>
+        public open override /*1*/ /*fake_override*/ fun hashCode(): kotlin.Int
+        public open override /*1*/ /*fake_override*/ fun toString(): kotlin.String
+    }
+
+    public final class DerivedAlias : derived.Alias /* = derived.Intermediate */ {
+        public constructor DerivedAlias()
+        invisible_fake final override /*1*/ /*fake_override*/ val a: kotlin.String
+        protected/*protected and package*/ final override /*1*/ /*fake_override*/ var a: kotlin.String!
+        invisible_fake final override /*1*/ /*fake_override*/ val b: kotlin.String
+        invisible_fake final override /*1*/ /*fake_override*/ var b: kotlin.String!
+        public open override /*1*/ /*fake_override*/ fun equals(/*0*/ other: kotlin.Any?): kotlin.Boolean
+        public final fun foo(): kotlin.reflect.KMutableProperty0<kotlin.String!>
+        public open override /*1*/ /*fake_override*/ fun hashCode(): kotlin.Int
+        public open override /*1*/ /*fake_override*/ fun toString(): kotlin.String
+    }
+
+    public final class DerivedPublic : derived.IntermediatePublic {
+        public constructor DerivedPublic()
+        protected/*protected and package*/ final override /*1*/ /*fake_override*/ var a: kotlin.String!
+        public final override /*1*/ /*fake_override*/ val a: kotlin.String
+        invisible_fake final override /*1*/ /*fake_override*/ var b: kotlin.String!
+        public open override /*1*/ /*fake_override*/ fun equals(/*0*/ other: kotlin.Any?): kotlin.Boolean
+        public final fun foo(): kotlin.reflect.KMutableProperty0<kotlin.String!>
+        public open override /*1*/ /*fake_override*/ fun hashCode(): kotlin.Int
+        public open override /*1*/ /*fake_override*/ fun toString(): kotlin.String
+    }
+
+    public final class DerivedWithoutBackingField : derived.IntermediateWithoutField {
+        public constructor DerivedWithoutBackingField()
+        invisible_fake final override /*1*/ /*fake_override*/ val a: kotlin.String
+        protected/*protected and package*/ final override /*1*/ /*fake_override*/ var a: kotlin.String!
+        invisible_fake final override /*1*/ /*fake_override*/ var b: kotlin.String!
+        public open override /*1*/ /*fake_override*/ fun equals(/*0*/ other: kotlin.Any?): kotlin.Boolean
+        public final fun foo(): kotlin.reflect.KMutableProperty0<kotlin.String!>
+        public open override /*1*/ /*fake_override*/ fun hashCode(): kotlin.Int
+        public open override /*1*/ /*fake_override*/ fun toString(): kotlin.String
+    }
+
+    public final class DirectlyDerived : base.BaseJava {
+        public constructor DirectlyDerived()
+        protected/*protected and package*/ final override /*1*/ /*fake_override*/ var a: kotlin.String!
+        invisible_fake final override /*1*/ /*fake_override*/ var b: kotlin.String!
+        public open override /*1*/ /*fake_override*/ fun equals(/*0*/ other: kotlin.Any?): kotlin.Boolean
+        public final fun foo(): kotlin.reflect.KMutableProperty0<kotlin.String!>
+        public open override /*1*/ /*fake_override*/ fun hashCode(): kotlin.Int
+        public open override /*1*/ /*fake_override*/ fun toString(): kotlin.String
+    }
+
+    public open class Intermediate : base.BaseJava {
+        public constructor Intermediate()
+        private final val a: kotlin.String = ""
+        protected/*protected and package*/ final override /*1*/ /*fake_override*/ var a: kotlin.String!
+        private final val b: kotlin.String = ""
+        invisible_fake final override /*1*/ /*fake_override*/ var b: kotlin.String!
+        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 IntermediatePublic : base.BaseJava {
+        public constructor IntermediatePublic()
+        public final val a: kotlin.String = ""
+        protected/*protected and package*/ final override /*1*/ /*fake_override*/ var a: kotlin.String!
+        invisible_fake final override /*1*/ /*fake_override*/ var b: kotlin.String!
+        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 IntermediateWithoutField : base.BaseJava {
+        public constructor IntermediateWithoutField()
+        private final val a: kotlin.String
+        protected/*protected and package*/ final override /*1*/ /*fake_override*/ var a: kotlin.String!
+        invisible_fake final override /*1*/ /*fake_override*/ var b: kotlin.String!
+        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 typealias Alias = derived.Intermediate
+}