[NI] Properly support UnsafeVariance annotation

#KT-38134 Fixed
 #KT-34433 Fixed
 #KT-31823 Fixed

compiler/testData/codegen/box/inference/unsafeVarianceCodegen.kt

@@ -0,0 +1,11 @@
+class A<out K> {
+    fun foo(x: @UnsafeVariance K): K = x
+}
+
+fun test(a: A<*>): Any? {
+    return a.foo("OK")
+}
+
+fun box(): String {
+    return test(A<String>()) as String
+}

compiler/testData/diagnostics/tests/generics/projectionsScope/unsafeVarianceInAliasedFunctionalType.kt

@@ -0,0 +1,13 @@
+// FIR_IDENTICAL
+
+class Foo<out T>(val baz: Baz<T>)
+
+class Bar {
+    val foo: Foo<*> = TODO()
+
+    fun <T> bar(): Baz<T> {
+        return foo.baz
+    }
+}
+
+typealias Baz<T> = (@UnsafeVariance T) -> Unit

compiler/testData/diagnostics/tests/generics/projectionsScope/unsafeVarianceInAliasedFunctionalType.txt

@@ -0,0 +1,19 @@
+package
+
+public final class Bar {
+    public constructor Bar()
+    public final val foo: Foo<*>
+    public final fun </*0*/ T> bar(): Baz<T> /* = (@kotlin.UnsafeVariance T) -> kotlin.Unit */
+    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 Foo</*0*/ out T> {
+    public constructor Foo</*0*/ out T>(/*0*/ baz: Baz<T> /* = (@kotlin.UnsafeVariance T) -> kotlin.Unit */)
+    public final val baz: Baz<T> /* = (@kotlin.UnsafeVariance T) -> kotlin.Unit */
+    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 Baz</*0*/ T> = (@kotlin.UnsafeVariance T) -> kotlin.Unit

compiler/testData/diagnostics/tests/generics/projectionsScope/unsafeVarianceOnInputTypeOfFunctionalType.kt

@@ -0,0 +1,22 @@
+// FIR_IDENTICAL
+// !DIAGNOSTICS: -UNUSED_PARAMETER -REDUNDANT_PROJECTION
+
+class FunctionHolder<out T : Any>(val f: (@UnsafeVariance T) -> Unit) {
+    fun f2(v: @UnsafeVariance T) {}
+}
+
+fun caller(
+    holder1: FunctionHolder<out Any>,
+    holder2: FunctionHolder<*>,
+    holder3: FunctionHolder<Any>,
+    a: Any
+) {
+    holder1.f(a)
+    holder1.f2(a)
+
+    holder2.f(a)
+    holder2.f2(a)
+
+    holder3.f(a)
+    holder3.f2(a)
+}

compiler/testData/diagnostics/tests/generics/projectionsScope/unsafeVarianceOnInputTypeOfFunctionalType.txt

@@ -0,0 +1,12 @@
+package
+
+public fun caller(/*0*/ holder1: FunctionHolder<out kotlin.Any>, /*1*/ holder2: FunctionHolder<*>, /*2*/ holder3: FunctionHolder<kotlin.Any>, /*3*/ a: kotlin.Any): kotlin.Unit
+
+public final class FunctionHolder</*0*/ out T : kotlin.Any> {
+    public constructor FunctionHolder</*0*/ out T : kotlin.Any>(/*0*/ f: (@kotlin.UnsafeVariance T) -> kotlin.Unit)
+    public final val f: (@kotlin.UnsafeVariance T) -> kotlin.Unit
+    public open override /*1*/ /*fake_override*/ fun equals(/*0*/ other: kotlin.Any?): kotlin.Boolean
+    public final fun f2(/*0*/ v: @kotlin.UnsafeVariance T): kotlin.Unit
+    public open override /*1*/ /*fake_override*/ fun hashCode(): kotlin.Int
+    public open override /*1*/ /*fake_override*/ fun toString(): kotlin.String
+}

compiler/testData/diagnostics/tests/generics/projectionsScope/unsafeVarianceStar.fir.kt

@@ -1,10 +0,0 @@
-// !WITH_NEW_INFERENCE
-
-interface A<out K> {
-    fun foo(x: @UnsafeVariance K): Unit
-}
-
-fun test(a: A<*>) {
-    a.foo(null)
-    a.foo(Any())
-}

compiler/testData/diagnostics/tests/generics/projectionsScope/unsafeVarianceStar.kt

@@ -1,10 +1,10 @@
-// !WITH_NEW_INFERENCE
+// FIR_IDENTICAL
 
 interface A<out K> {
     fun foo(x: @UnsafeVariance K): Unit
 }
 
 fun test(a: A<*>) {
-    a.foo(<!NI;NULL_FOR_NONNULL_TYPE!>null<!>)
-    a.foo(<!NI;TYPE_MISMATCH!>Any()<!>)
+    a.foo(null)
+    a.foo(Any())
 }

compiler/testData/diagnostics/tests/generics/projectionsScope/unsafeVarianceWithRecursiveGenerics.fir.kt

@@ -0,0 +1,11 @@
+interface UpdatableRendering<out T : UpdatableRendering<T>> {
+    fun canUpdateFrom(another: @UnsafeVariance T): Boolean
+}
+
+internal fun Any.matchesRendering(other: Any): Boolean {
+    return when {
+        this::class != other::class -> false
+        this !is UpdatableRendering<*> -> true
+        else -> this.<!INAPPLICABLE_CANDIDATE!>canUpdateFrom<!>(other as UpdatableRendering<*>)
+    }
+}

compiler/testData/diagnostics/tests/generics/projectionsScope/unsafeVarianceWithRecursiveGenerics.kt

@@ -0,0 +1,11 @@
+interface UpdatableRendering<out T : UpdatableRendering<T>> {
+    fun canUpdateFrom(another: @UnsafeVariance T): Boolean
+}
+
+internal fun Any.matchesRendering(other: Any): Boolean {
+    return when {
+        this::class != other::class -> false
+        this !is UpdatableRendering<*> -> true
+        else -> <!DEBUG_INFO_SMARTCAST!>this<!>.canUpdateFrom(other as UpdatableRendering<*>)
+    }
+}

compiler/testData/diagnostics/tests/generics/projectionsScope/unsafeVarianceWithRecursiveGenerics.txt

@@ -0,0 +1,10 @@
+package
+
+internal fun kotlin.Any.matchesRendering(/*0*/ other: kotlin.Any): kotlin.Boolean
+
+public interface UpdatableRendering</*0*/ out T : UpdatableRendering<T>> {
+    public abstract fun canUpdateFrom(/*0*/ another: @kotlin.UnsafeVariance T): kotlin.Boolean
+    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
+}