[FIR] Handle 'EnhancedNullability' more properly

This commit includes three changes:
1. 'EnhancedNullability' is no more set for declaration types
2. It is no more used for conversion types in translator
3. Translator inserts implicit not-null cast only when enhanced type is cast to not-null type.

compiler/fir/analysis-tests/testData/resolveWithStdlib/j+k/BasicWithAnnotatedJava.txt

@@ -5,8 +5,8 @@ FILE: jvm.kt
         }
 
         public final fun test(): R|kotlin/Unit| {
-            lval x: R|@EnhancedNullability kotlin/String| = this@R|/User|.R|/Annotated.foo|(String(123))
+            lval x: R|kotlin/String| = this@R|/User|.R|/Annotated.foo|(String(123))
-            lval y: R|@EnhancedNullability kotlin/String| = this@R|/User|.R|/Annotated.foo|(Null(null))
+            lval y: R|kotlin/String| = this@R|/User|.R|/Annotated.foo|(Null(null))
         }
 
     }

compiler/fir/fir2ir/src/org/jetbrains/kotlin/fir/backend/Fir2IrImplicitCastInserter.kt

@@ -29,7 +29,10 @@ import org.jetbrains.kotlin.ir.IrElement
 import org.jetbrains.kotlin.ir.expressions.*
 import org.jetbrains.kotlin.ir.expressions.impl.IrTypeOperatorCallImpl
 import org.jetbrains.kotlin.ir.types.IrType
+import org.jetbrains.kotlin.ir.types.removeAnnotations
+import org.jetbrains.kotlin.ir.util.classId
 import org.jetbrains.kotlin.ir.util.coerceToUnitIfNeeded
+import org.jetbrains.kotlin.ir.util.parentAsClass
 import org.jetbrains.kotlin.name.Name
 
 class Fir2IrImplicitCastInserter(
@@ -206,8 +209,7 @@ class Fir2IrImplicitCastInserter(
             expectedType.isUnit -> {
                 coerceToUnitIfNeeded(type, irBuiltIns)
             }
-            // TODO: Not exactly matched with psi2ir yet...
+            valueType.hasEnhancedNullability() && !expectedType.acceptsNullValues() -> {
-            valueType.hasEnhancedNullability() -> {
                 insertImplicitNotNullCastIfNeeded(expression)
             }
             // TODO: coerceIntToAnotherIntegerType
@@ -216,18 +218,24 @@ class Fir2IrImplicitCastInserter(
         }
     }
 
+    private fun FirTypeRef.acceptsNullValues(): Boolean =
+        isMarkedNullable == true || hasEnhancedNullability()
+
     private fun IrExpression.insertImplicitNotNullCastIfNeeded(expression: FirExpression): IrExpression {
         // [TypeOperatorLowering] will retrieve the source (from start offset to end offset) as an assertion message.
         // Avoid type casting if we can't determine the source for some reasons, e.g., implicit `this` receiver.
         if (expression.source == null) {
             return this
         }
+        val castType = type.removeAnnotations {
+            it.symbol.owner.parentAsClass.classId == CompilerConeAttributes.EnhancedNullability.ANNOTATION_CLASS_ID
+        }
         return IrTypeOperatorCallImpl(
             this.startOffset,
             this.endOffset,
-            this.type,
+            castType,
             IrTypeOperator.IMPLICIT_NOTNULL,
-            this.type,
+            castType,
             this
         )
     }

compiler/fir/resolve/src/org/jetbrains/kotlin/fir/types/TypeUtils.kt

@@ -11,6 +11,7 @@ import org.jetbrains.kotlin.fir.FirFakeSourceElementKind
 import org.jetbrains.kotlin.fir.FirSession
 import org.jetbrains.kotlin.fir.declarations.classId
 import org.jetbrains.kotlin.fir.diagnostics.ConeSimpleDiagnostic
+import org.jetbrains.kotlin.fir.expressions.classId
 import org.jetbrains.kotlin.fir.fakeElement
 import org.jetbrains.kotlin.fir.render
 import org.jetbrains.kotlin.fir.resolve.fullyExpandedType
@@ -83,6 +84,7 @@ fun <T : ConeKotlinType> T.withAttributes(attributes: ConeAttributes): T {
         is ConeClassLikeTypeImpl -> ConeClassLikeTypeImpl(lookupTag, typeArguments, nullability.isNullable, attributes)
         is ConeDefinitelyNotNullType -> ConeDefinitelyNotNullType.create(original.withAttributes(attributes))!!
         is ConeTypeParameterTypeImpl -> ConeTypeParameterTypeImpl(lookupTag, nullability.isNullable, attributes)
+        is ConeFlexibleType -> ConeFlexibleType(lowerBound.withAttributes(attributes), upperBound.withAttributes(attributes))
         else -> error("Not supported: $this: ${this.render()}")
     } as T
 }
@@ -186,6 +188,20 @@ fun FirTypeRef.isUnsafeVarianceType(session: FirSession): Boolean {
 fun FirTypeRef.hasEnhancedNullability(): Boolean =
     coneTypeSafe<ConeKotlinType>()?.hasEnhancedNullability == true
 
+fun FirTypeRef.withoutEnhancedNullability(): FirTypeRef {
+    require(this is FirResolvedTypeRef)
+    if (!hasEnhancedNullability()) return this
+    return buildResolvedTypeRef {
+        source = this@withoutEnhancedNullability.source
+        type = this@withoutEnhancedNullability.type.withAttributes(
+            ConeAttributes.create(
+                this@withoutEnhancedNullability.type.attributes.filter { it != CompilerConeAttributes.EnhancedNullability }
+            )
+        )
+        annotations += this@withoutEnhancedNullability.annotations
+    }
+}
+
 // Unlike other cases, return types may be implicit, i.e. unresolved
 // But in that cases newType should also be `null`
 fun FirTypeRef.withReplacedReturnType(newType: ConeKotlinType?): FirTypeRef {
@@ -240,7 +256,7 @@ fun FirTypeRef.approximatedIfNeededOrSelf(
     } else {
         this
     }
-    return approximatedType.hideLocalTypeIfNeeded(containingCallableVisibility, isInlineFunction)
+    return approximatedType.hideLocalTypeIfNeeded(containingCallableVisibility, isInlineFunction).withoutEnhancedNullability()
 }
 
 private fun ConeKotlinType.requiresApproximationInPublicPosition(): Boolean {

compiler/ir/ir.tree/src/org/jetbrains/kotlin/ir/types/irTypes.kt

@@ -50,6 +50,18 @@ fun IrType.addAnnotations(newAnnotations: List<IrConstructorCall>): IrType =
             this
     }
 
+fun IrType.removeAnnotations(predicate: (IrConstructorCall) -> Boolean): IrType =
+    when (this) {
+        is IrSimpleType ->
+            toBuilder().apply {
+                annotations = annotations.filterNot(predicate)
+            }.buildSimpleType()
+        is IrDynamicType ->
+            IrDynamicTypeImpl(null, annotations.filterNot(predicate), Variance.INVARIANT)
+        else ->
+            this
+    }
+
 val IrType.classifierOrFail: IrClassifierSymbol
     get() = cast<IrSimpleType>().classifier
 

compiler/testData/codegen/box/javaInterop/notNullAssertions/enhancedNullability/inLambdaReturnWithExpectedType.kt

@@ -1,5 +1,4 @@
 // !LANGUAGE: +StrictJavaNullabilityAssertions
-// IGNORE_BACKEND_FIR: JVM_IR
 // TARGET_BACKEND: JVM
 
 // FILE: inLambdaReturnWithExpectedType.kt

compiler/testData/codegen/box/javaInterop/notNullAssertions/nullCheckOnLambdaReturnValue/nnStringVsT.kt

@@ -1,5 +1,4 @@
 // TARGET_BACKEND: JVM
-// IGNORE_BACKEND_FIR: JVM_IR
 // FILE: nnStringVsT.kt
 fun <T> useT(fn: () -> T) = fn()
 

compiler/testData/codegen/box/javaInterop/notNullAssertions/nullCheckOnLambdaReturnValue/nnStringVsTAny.kt

@@ -1,5 +1,4 @@
 // TARGET_BACKEND: JVM
-// IGNORE_BACKEND_FIR: JVM_IR
 // FILE: nnStringVsTAny.kt
 fun <T : Any> useTAny(fn: () -> T) = fn()
 

compiler/testData/ir/irText/expressions/nullCheckOnGenericLambdaReturn.fir.txt

@@ -41,18 +41,17 @@ FILE fqName:<root> fileName:/nullCheckOnGenericLambdaReturn.kt
               BLOCK_BODY
                 RETURN type=kotlin.Nothing from='local final fun <anonymous> (): kotlin.String? declared in <root>.test1'
                   CALL 'public open fun foo (): kotlin.String? declared in <root>.J' type=kotlin.String? origin=null
-  FUN name:test2 visibility:public modality:FINAL <> () returnType:@[EnhancedNullability] kotlin.String
+  FUN name:test2 visibility:public modality:FINAL <> () returnType:kotlin.String
     BLOCK_BODY
-      RETURN type=kotlin.Nothing from='public final fun test2 (): @[EnhancedNullability] kotlin.String declared in <root>'
+      RETURN type=kotlin.Nothing from='public final fun test2 (): kotlin.String declared in <root>'
-        TYPE_OP type=@[EnhancedNullability] kotlin.String origin=IMPLICIT_NOTNULL typeOperand=@[EnhancedNullability] kotlin.String
+        TYPE_OP type=kotlin.String origin=IMPLICIT_NOTNULL typeOperand=kotlin.String
           CALL 'public final fun checkT <T> (fn: kotlin.Function0<T of <root>.checkT>): T of <root>.checkT declared in <root>' type=@[EnhancedNullability] kotlin.String origin=null
             <T>: @[EnhancedNullability] kotlin.String
             fn: FUN_EXPR type=kotlin.Function0<@[EnhancedNullability] kotlin.String> origin=LAMBDA
               FUN LOCAL_FUNCTION_FOR_LAMBDA name:<anonymous> visibility:local modality:FINAL <> () returnType:@[EnhancedNullability] kotlin.String
                 BLOCK_BODY
                   RETURN type=kotlin.Nothing from='local final fun <anonymous> (): @[EnhancedNullability] kotlin.String declared in <root>.test2'
-                    TYPE_OP type=@[EnhancedNullability] kotlin.String origin=IMPLICIT_NOTNULL typeOperand=@[EnhancedNullability] kotlin.String
+                    CALL 'public open fun nnFoo (): @[EnhancedNullability] kotlin.String declared in <root>.J' type=@[EnhancedNullability] kotlin.String origin=null
-                      CALL 'public open fun nnFoo (): @[EnhancedNullability] kotlin.String declared in <root>.J' type=@[EnhancedNullability] kotlin.String origin=null
   FUN name:test3 visibility:public modality:FINAL <> () returnType:kotlin.String?
     BLOCK_BODY
       RETURN type=kotlin.Nothing from='public final fun test3 (): kotlin.String? declared in <root>'
@@ -63,15 +62,14 @@ FILE fqName:<root> fileName:/nullCheckOnGenericLambdaReturn.kt
               BLOCK_BODY
                 RETURN type=kotlin.Nothing from='local final fun <anonymous> (): kotlin.String? declared in <root>.test3'
                   CALL 'public open fun foo (): kotlin.String? declared in <root>.J' type=kotlin.String? origin=null
-  FUN name:test4 visibility:public modality:FINAL <> () returnType:@[EnhancedNullability] kotlin.String
+  FUN name:test4 visibility:public modality:FINAL <> () returnType:kotlin.String
     BLOCK_BODY
-      RETURN type=kotlin.Nothing from='public final fun test4 (): @[EnhancedNullability] kotlin.String declared in <root>'
+      RETURN type=kotlin.Nothing from='public final fun test4 (): kotlin.String declared in <root>'
-        TYPE_OP type=@[EnhancedNullability] kotlin.String origin=IMPLICIT_NOTNULL typeOperand=@[EnhancedNullability] kotlin.String
+        TYPE_OP type=kotlin.String origin=IMPLICIT_NOTNULL typeOperand=kotlin.String
           CALL 'public final fun checkTAny <T> (fn: kotlin.Function0<T of <root>.checkTAny>): T of <root>.checkTAny declared in <root>' type=@[EnhancedNullability] kotlin.String origin=null
             <T>: @[EnhancedNullability] kotlin.String
             fn: FUN_EXPR type=kotlin.Function0<@[EnhancedNullability] kotlin.String> origin=LAMBDA
               FUN LOCAL_FUNCTION_FOR_LAMBDA name:<anonymous> visibility:local modality:FINAL <> () returnType:@[EnhancedNullability] kotlin.String
                 BLOCK_BODY
                   RETURN type=kotlin.Nothing from='local final fun <anonymous> (): @[EnhancedNullability] kotlin.String declared in <root>.test4'
-                    TYPE_OP type=@[EnhancedNullability] kotlin.String origin=IMPLICIT_NOTNULL typeOperand=@[EnhancedNullability] kotlin.String
+                    CALL 'public open fun nnFoo (): @[EnhancedNullability] kotlin.String declared in <root>.J' type=@[EnhancedNullability] kotlin.String origin=null
-                      CALL 'public open fun nnFoo (): @[EnhancedNullability] kotlin.String declared in <root>.J' type=@[EnhancedNullability] kotlin.String origin=null

compiler/testData/ir/irText/expressions/nullCheckOnLambdaReturn.fir.txt

@@ -85,5 +85,4 @@ FILE fqName:<root> fileName:/nullCheckOnLambdaReturn.kt
             FUN LOCAL_FUNCTION_FOR_LAMBDA name:<anonymous> visibility:local modality:FINAL <> () returnType:kotlin.Any?
               BLOCK_BODY
                 RETURN type=kotlin.Nothing from='local final fun <anonymous> (): kotlin.Any? declared in <root>.test6'
-                  TYPE_OP type=@[EnhancedNullability] kotlin.String origin=IMPLICIT_NOTNULL typeOperand=@[EnhancedNullability] kotlin.String
+                  CALL 'public open fun nnFoo (): @[EnhancedNullability] kotlin.String declared in <root>.J' type=@[EnhancedNullability] kotlin.String origin=null
-                    CALL 'public open fun nnFoo (): @[EnhancedNullability] kotlin.String declared in <root>.J' type=@[EnhancedNullability] kotlin.String origin=null

compiler/testData/ir/irText/types/nullChecks/enhancedNullability.fir.txt

@@ -5,51 +5,49 @@ FILE fqName:<root> fileName:/enhancedNullability.kt
   FUN name:testUse visibility:public modality:FINAL <> () returnType:kotlin.Unit
     BLOCK_BODY
       CALL 'public final fun use (s: kotlin.String): kotlin.Unit declared in <root>' type=kotlin.Unit origin=null
-        s: TYPE_OP type=@[EnhancedNullability] kotlin.String origin=IMPLICIT_NOTNULL typeOperand=@[EnhancedNullability] kotlin.String
+        s: TYPE_OP type=kotlin.String origin=IMPLICIT_NOTNULL typeOperand=kotlin.String
           CALL 'public open fun notNullString (): @[EnhancedNullability] kotlin.String declared in <root>.J' type=@[EnhancedNullability] kotlin.String origin=null
   FUN name:testLocalVal visibility:public modality:FINAL <> () returnType:kotlin.Unit
     BLOCK_BODY
-      VAR name:local type:@[EnhancedNullability] kotlin.String [val]
+      VAR name:local type:kotlin.String [val]
-        TYPE_OP type=@[EnhancedNullability] kotlin.String origin=IMPLICIT_NOTNULL typeOperand=@[EnhancedNullability] kotlin.String
+        TYPE_OP type=kotlin.String origin=IMPLICIT_NOTNULL typeOperand=kotlin.String
           CALL 'public open fun notNullString (): @[EnhancedNullability] kotlin.String declared in <root>.J' type=@[EnhancedNullability] kotlin.String origin=null
-  FUN name:testReturnValue visibility:public modality:FINAL <> () returnType:@[EnhancedNullability] kotlin.String
+  FUN name:testReturnValue visibility:public modality:FINAL <> () returnType:kotlin.String
     BLOCK_BODY
-      RETURN type=kotlin.Nothing from='public final fun testReturnValue (): @[EnhancedNullability] kotlin.String declared in <root>'
+      RETURN type=kotlin.Nothing from='public final fun testReturnValue (): kotlin.String declared in <root>'
-        TYPE_OP type=@[EnhancedNullability] kotlin.String origin=IMPLICIT_NOTNULL typeOperand=@[EnhancedNullability] kotlin.String
+        TYPE_OP type=kotlin.String origin=IMPLICIT_NOTNULL typeOperand=kotlin.String
           CALL 'public open fun notNullString (): @[EnhancedNullability] kotlin.String declared in <root>.J' type=@[EnhancedNullability] kotlin.String origin=null
   PROPERTY name:testGlobalVal visibility:public modality:FINAL [val]
-    FIELD PROPERTY_BACKING_FIELD name:testGlobalVal type:@[EnhancedNullability] kotlin.String visibility:private [final,static]
+    FIELD PROPERTY_BACKING_FIELD name:testGlobalVal type:kotlin.String visibility:private [final,static]
       EXPRESSION_BODY
-        TYPE_OP type=@[EnhancedNullability] kotlin.String origin=IMPLICIT_NOTNULL typeOperand=@[EnhancedNullability] kotlin.String
+        TYPE_OP type=kotlin.String origin=IMPLICIT_NOTNULL typeOperand=kotlin.String
           CALL 'public open fun notNullString (): @[EnhancedNullability] kotlin.String declared in <root>.J' type=@[EnhancedNullability] kotlin.String origin=null
-    FUN DEFAULT_PROPERTY_ACCESSOR name:<get-testGlobalVal> visibility:public modality:FINAL <> () returnType:@[EnhancedNullability] kotlin.String
+    FUN DEFAULT_PROPERTY_ACCESSOR name:<get-testGlobalVal> visibility:public modality:FINAL <> () returnType:kotlin.String
       correspondingProperty: PROPERTY name:testGlobalVal visibility:public modality:FINAL [val]
       BLOCK_BODY
-        RETURN type=kotlin.Nothing from='public final fun <get-testGlobalVal> (): @[EnhancedNullability] kotlin.String declared in <root>'
+        RETURN type=kotlin.Nothing from='public final fun <get-testGlobalVal> (): kotlin.String declared in <root>'
-          GET_FIELD 'FIELD PROPERTY_BACKING_FIELD name:testGlobalVal type:@[EnhancedNullability] kotlin.String visibility:private [final,static]' type=@[EnhancedNullability] kotlin.String origin=null
+          GET_FIELD 'FIELD PROPERTY_BACKING_FIELD name:testGlobalVal type:kotlin.String visibility:private [final,static]' type=kotlin.String origin=null
   PROPERTY name:testGlobalValGetter visibility:public modality:FINAL [val]
-    FUN name:<get-testGlobalValGetter> visibility:public modality:FINAL <> () returnType:@[EnhancedNullability] kotlin.String
+    FUN name:<get-testGlobalValGetter> visibility:public modality:FINAL <> () returnType:kotlin.String
       correspondingProperty: PROPERTY name:testGlobalValGetter visibility:public modality:FINAL [val]
       BLOCK_BODY
-        RETURN type=kotlin.Nothing from='public final fun <get-testGlobalValGetter> (): @[EnhancedNullability] kotlin.String declared in <root>'
+        RETURN type=kotlin.Nothing from='public final fun <get-testGlobalValGetter> (): kotlin.String declared in <root>'
-          TYPE_OP type=@[EnhancedNullability] kotlin.String origin=IMPLICIT_NOTNULL typeOperand=@[EnhancedNullability] kotlin.String
+          TYPE_OP type=kotlin.String origin=IMPLICIT_NOTNULL typeOperand=kotlin.String
             CALL 'public open fun notNullString (): @[EnhancedNullability] kotlin.String declared in <root>.J' type=@[EnhancedNullability] kotlin.String origin=null
   FUN name:testJUse visibility:public modality:FINAL <> () returnType:kotlin.Unit
     BLOCK_BODY
       CALL 'public open fun use (s: @[EnhancedNullability] kotlin.String): kotlin.Unit declared in <root>.J' type=kotlin.Unit origin=null
         s: CALL 'public open fun nullString (): kotlin.String? declared in <root>.J' type=kotlin.String? origin=null
       CALL 'public open fun use (s: @[EnhancedNullability] kotlin.String): kotlin.Unit declared in <root>.J' type=kotlin.Unit origin=null
-        s: TYPE_OP type=@[EnhancedNullability] kotlin.String origin=IMPLICIT_NOTNULL typeOperand=@[EnhancedNullability] kotlin.String
+        s: CALL 'public open fun notNullString (): @[EnhancedNullability] kotlin.String declared in <root>.J' type=@[EnhancedNullability] kotlin.String origin=null
-          CALL 'public open fun notNullString (): @[EnhancedNullability] kotlin.String declared in <root>.J' type=@[EnhancedNullability] kotlin.String origin=null
   FUN name:testLocalVarUse visibility:public modality:FINAL <> () returnType:kotlin.Unit
     BLOCK_BODY
       VAR name:ns type:kotlin.String? [val]
         CALL 'public open fun nullString (): kotlin.String? declared in <root>.J' type=kotlin.String? origin=null
       CALL 'public open fun use (s: @[EnhancedNullability] kotlin.String): kotlin.Unit declared in <root>.J' type=kotlin.Unit origin=null
         s: GET_VAR 'val ns: kotlin.String? [val] declared in <root>.testLocalVarUse' type=kotlin.String? origin=null
-      VAR name:nns type:@[EnhancedNullability] kotlin.String [val]
+      VAR name:nns type:kotlin.String [val]
-        TYPE_OP type=@[EnhancedNullability] kotlin.String origin=IMPLICIT_NOTNULL typeOperand=@[EnhancedNullability] kotlin.String
+        TYPE_OP type=kotlin.String origin=IMPLICIT_NOTNULL typeOperand=kotlin.String
           CALL 'public open fun notNullString (): @[EnhancedNullability] kotlin.String declared in <root>.J' type=@[EnhancedNullability] kotlin.String origin=null
       CALL 'public open fun use (s: @[EnhancedNullability] kotlin.String): kotlin.Unit declared in <root>.J' type=kotlin.Unit origin=null
-        s: TYPE_OP type=@[EnhancedNullability] kotlin.String origin=IMPLICIT_NOTNULL typeOperand=@[EnhancedNullability] kotlin.String
+        s: GET_VAR 'val nns: kotlin.String [val] declared in <root>.testLocalVarUse' type=kotlin.String origin=null
-          GET_VAR 'val nns: @[EnhancedNullability] kotlin.String [val] declared in <root>.testLocalVarUse' type=@[EnhancedNullability] kotlin.String origin=null

compiler/testData/ir/irText/types/nullChecks/enhancedNullabilityInDestructuringAssignment.fir.txt

@@ -117,15 +117,15 @@ FILE fqName:<root> fileName:/enhancedNullabilityInDestructuringAssignment.kt
       $this: VALUE_PARAMETER name:<this> type:kotlin.Any
   FUN name:test1 visibility:public modality:FINAL <> () returnType:kotlin.Unit
     BLOCK_BODY
-      VAR IR_TEMPORARY_VARIABLE name:tmp_0 type:@[EnhancedNullability] <root>.P [val]
+      VAR IR_TEMPORARY_VARIABLE name:tmp_0 type:<root>.P [val]
-        TYPE_OP type=@[EnhancedNullability] <root>.P origin=IMPLICIT_NOTNULL typeOperand=@[EnhancedNullability] <root>.P
+        TYPE_OP type=<root>.P origin=IMPLICIT_NOTNULL typeOperand=<root>.P
           CALL 'public open fun notNullP (): @[EnhancedNullability] <root>.P declared in <root>.J' type=@[EnhancedNullability] <root>.P origin=null
       VAR name:x type:kotlin.Int [val]
         CALL 'public final fun component1 (): kotlin.Int [operator] declared in <root>.P' type=kotlin.Int origin=null
-          $this: GET_VAR 'val tmp_0: @[EnhancedNullability] <root>.P [val] declared in <root>.test1' type=@[EnhancedNullability] <root>.P origin=null
+          $this: GET_VAR 'val tmp_0: <root>.P [val] declared in <root>.test1' type=<root>.P origin=null
       VAR name:y type:kotlin.Int [val]
         CALL 'public final fun component2 (): kotlin.Int [operator] declared in <root>.P' type=kotlin.Int origin=null
-          $this: GET_VAR 'val tmp_0: @[EnhancedNullability] <root>.P [val] declared in <root>.test1' type=@[EnhancedNullability] <root>.P origin=null
+          $this: GET_VAR 'val tmp_0: <root>.P [val] declared in <root>.test1' type=<root>.P origin=null
       CALL 'public final fun use (x: kotlin.Any, y: kotlin.Any): kotlin.Unit declared in <root>' type=kotlin.Unit origin=null
         x: GET_VAR 'val x: kotlin.Int [val] declared in <root>.test1' type=kotlin.Int origin=null
         y: GET_VAR 'val y: kotlin.Int [val] declared in <root>.test1' type=kotlin.Int origin=null

compiler/testData/ir/irText/types/nullChecks/nullCheckOnLambdaResult/nnStringVsT.fir.txt

@@ -1,19 +0,0 @@
-FILE fqName:<root> fileName:/nnStringVsT.kt
-  FUN name:useT visibility:public modality:FINAL <T> (fn:kotlin.Function0<T of <root>.useT>) returnType:T of <root>.useT
-    TYPE_PARAMETER name:T index:0 variance: superTypes:[kotlin.Any?]
-    VALUE_PARAMETER name:fn index:0 type:kotlin.Function0<T of <root>.useT>
-    BLOCK_BODY
-      RETURN type=kotlin.Nothing from='public final fun useT <T> (fn: kotlin.Function0<T of <root>.useT>): T of <root>.useT declared in <root>'
-        CALL 'public abstract fun invoke (): R of kotlin.Function0 [operator] declared in kotlin.Function0' type=T of <root>.useT origin=INVOKE
-          $this: GET_VAR 'fn: kotlin.Function0<T of <root>.useT> declared in <root>.useT' type=kotlin.Function0<T of <root>.useT> origin=VARIABLE_AS_FUNCTION
-  FUN name:testNoNullCheck visibility:public modality:FINAL <> () returnType:kotlin.Unit
-    BLOCK_BODY
-      TYPE_OP type=kotlin.Unit origin=IMPLICIT_COERCION_TO_UNIT typeOperand=kotlin.Unit
-        CALL 'public final fun useT <T> (fn: kotlin.Function0<T of <root>.useT>): T of <root>.useT declared in <root>' type=@[EnhancedNullability] kotlin.String origin=null
-          <T>: @[EnhancedNullability] kotlin.String
-          fn: FUN_EXPR type=kotlin.Function0<@[EnhancedNullability] kotlin.String> origin=LAMBDA
-            FUN LOCAL_FUNCTION_FOR_LAMBDA name:<anonymous> visibility:local modality:FINAL <> () returnType:@[EnhancedNullability] kotlin.String
-              BLOCK_BODY
-                RETURN type=kotlin.Nothing from='local final fun <anonymous> (): @[EnhancedNullability] kotlin.String declared in <root>.testNoNullCheck'
-                  TYPE_OP type=@[EnhancedNullability] kotlin.String origin=IMPLICIT_NOTNULL typeOperand=@[EnhancedNullability] kotlin.String
-                    CALL 'public open fun notNullString (): @[EnhancedNullability] kotlin.String declared in <root>.J' type=@[EnhancedNullability] kotlin.String origin=null

compiler/testData/ir/irText/types/nullChecks/nullCheckOnLambdaResult/nnStringVsT.kt

@@ -1,3 +1,4 @@
+// FIR_IDENTICAL
 // FILE: nnStringVsT.kt
 fun <T> useT(fn: () -> T) = fn()
 

compiler/testData/ir/irText/types/nullChecks/nullCheckOnLambdaResult/nnStringVsTAny.fir.txt

@@ -1,19 +0,0 @@
-FILE fqName:<root> fileName:/nnStringVsTAny.kt
-  FUN name:useTAny visibility:public modality:FINAL <T> (fn:kotlin.Function0<T of <root>.useTAny>) returnType:T of <root>.useTAny
-    TYPE_PARAMETER name:T index:0 variance: superTypes:[kotlin.Any]
-    VALUE_PARAMETER name:fn index:0 type:kotlin.Function0<T of <root>.useTAny>
-    BLOCK_BODY
-      RETURN type=kotlin.Nothing from='public final fun useTAny <T> (fn: kotlin.Function0<T of <root>.useTAny>): T of <root>.useTAny declared in <root>'
-        CALL 'public abstract fun invoke (): R of kotlin.Function0 [operator] declared in kotlin.Function0' type=T of <root>.useTAny origin=INVOKE
-          $this: GET_VAR 'fn: kotlin.Function0<T of <root>.useTAny> declared in <root>.useTAny' type=kotlin.Function0<T of <root>.useTAny> origin=VARIABLE_AS_FUNCTION
-  FUN name:testNoNullCheck visibility:public modality:FINAL <> () returnType:kotlin.Unit
-    BLOCK_BODY
-      TYPE_OP type=kotlin.Unit origin=IMPLICIT_COERCION_TO_UNIT typeOperand=kotlin.Unit
-        CALL 'public final fun useTAny <T> (fn: kotlin.Function0<T of <root>.useTAny>): T of <root>.useTAny declared in <root>' type=@[EnhancedNullability] kotlin.String origin=null
-          <T>: @[EnhancedNullability] kotlin.String
-          fn: FUN_EXPR type=kotlin.Function0<@[EnhancedNullability] kotlin.String> origin=LAMBDA
-            FUN LOCAL_FUNCTION_FOR_LAMBDA name:<anonymous> visibility:local modality:FINAL <> () returnType:@[EnhancedNullability] kotlin.String
-              BLOCK_BODY
-                RETURN type=kotlin.Nothing from='local final fun <anonymous> (): @[EnhancedNullability] kotlin.String declared in <root>.testNoNullCheck'
-                  TYPE_OP type=@[EnhancedNullability] kotlin.String origin=IMPLICIT_NOTNULL typeOperand=@[EnhancedNullability] kotlin.String
-                    CALL 'public open fun notNullString (): @[EnhancedNullability] kotlin.String declared in <root>.J' type=@[EnhancedNullability] kotlin.String origin=null

compiler/testData/ir/irText/types/nullChecks/nullCheckOnLambdaResult/nnStringVsTAny.kt

@@ -1,3 +1,4 @@
+// FIR_IDENTICAL
 // FILE: nnStringVsTAny.kt
 fun <T : Any> useTAny(fn: () -> T) = fn()
 

compiler/testData/ir/irText/types/nullChecks/nullCheckOnLambdaResult/nnStringVsTConstrained.fir.txt

@@ -1,22 +0,0 @@
-FILE fqName:<root> fileName:/nnStringVsTConstrained.kt
-  FUN name:useTConstrained visibility:public modality:FINAL <T> (xs:kotlin.Array<T of <root>.useTConstrained>, fn:kotlin.Function0<T of <root>.useTConstrained>) returnType:T of <root>.useTConstrained
-    TYPE_PARAMETER name:T index:0 variance: superTypes:[kotlin.Any?]
-    VALUE_PARAMETER name:xs index:0 type:kotlin.Array<T of <root>.useTConstrained>
-    VALUE_PARAMETER name:fn index:1 type:kotlin.Function0<T of <root>.useTConstrained>
-    BLOCK_BODY
-      RETURN type=kotlin.Nothing from='public final fun useTConstrained <T> (xs: kotlin.Array<T of <root>.useTConstrained>, fn: kotlin.Function0<T of <root>.useTConstrained>): T of <root>.useTConstrained declared in <root>'
-        CALL 'public abstract fun invoke (): R of kotlin.Function0 [operator] declared in kotlin.Function0' type=T of <root>.useTConstrained origin=INVOKE
-          $this: GET_VAR 'fn: kotlin.Function0<T of <root>.useTConstrained> declared in <root>.useTConstrained' type=kotlin.Function0<T of <root>.useTConstrained> origin=VARIABLE_AS_FUNCTION
-  FUN name:testWithNullCheck visibility:public modality:FINAL <> (xs:kotlin.Array<kotlin.String>) returnType:kotlin.Unit
-    VALUE_PARAMETER name:xs index:0 type:kotlin.Array<kotlin.String>
-    BLOCK_BODY
-      TYPE_OP type=kotlin.Unit origin=IMPLICIT_COERCION_TO_UNIT typeOperand=kotlin.Unit
-        CALL 'public final fun useTConstrained <T> (xs: kotlin.Array<T of <root>.useTConstrained>, fn: kotlin.Function0<T of <root>.useTConstrained>): T of <root>.useTConstrained declared in <root>' type=kotlin.String origin=null
-          <T>: kotlin.String
-          xs: GET_VAR 'xs: kotlin.Array<kotlin.String> declared in <root>.testWithNullCheck' type=kotlin.Array<kotlin.String> origin=null
-          fn: FUN_EXPR type=kotlin.Function0<kotlin.String> origin=LAMBDA
-            FUN LOCAL_FUNCTION_FOR_LAMBDA name:<anonymous> visibility:local modality:FINAL <> () returnType:kotlin.String
-              BLOCK_BODY
-                RETURN type=kotlin.Nothing from='local final fun <anonymous> (): kotlin.String declared in <root>.testWithNullCheck'
-                  TYPE_OP type=@[EnhancedNullability] kotlin.String origin=IMPLICIT_NOTNULL typeOperand=@[EnhancedNullability] kotlin.String
-                    CALL 'public open fun notNullString (): @[EnhancedNullability] kotlin.String declared in <root>.J' type=@[EnhancedNullability] kotlin.String origin=null

compiler/testData/ir/irText/types/nullChecks/nullCheckOnLambdaResult/nnStringVsTConstrained.kt

@@ -1,3 +1,4 @@
+// FIR_IDENTICAL
 // FILE: nnStringVsTConstrained.kt
 fun <T> useTConstrained(xs: Array<T>, fn: () -> T) = fn()
 

compiler/testData/ir/irText/types/nullChecks/nullCheckOnLambdaResult/nnStringVsTXArray.fir.txt

@@ -1,22 +0,0 @@
-FILE fqName:<root> fileName:/nnStringVsTXArray.kt
-  FUN name:useTX visibility:public modality:FINAL <T> (x:T of <root>.useTX, fn:kotlin.Function0<T of <root>.useTX>) returnType:T of <root>.useTX
-    TYPE_PARAMETER name:T index:0 variance: superTypes:[kotlin.Any?]
-    VALUE_PARAMETER name:x index:0 type:T of <root>.useTX
-    VALUE_PARAMETER name:fn index:1 type:kotlin.Function0<T of <root>.useTX>
-    BLOCK_BODY
-      RETURN type=kotlin.Nothing from='public final fun useTX <T> (x: T of <root>.useTX, fn: kotlin.Function0<T of <root>.useTX>): T of <root>.useTX declared in <root>'
-        CALL 'public abstract fun invoke (): R of kotlin.Function0 [operator] declared in kotlin.Function0' type=T of <root>.useTX origin=INVOKE
-          $this: GET_VAR 'fn: kotlin.Function0<T of <root>.useTX> declared in <root>.useTX' type=kotlin.Function0<T of <root>.useTX> origin=VARIABLE_AS_FUNCTION
-  FUN name:testWithNullCheck visibility:public modality:FINAL <> (xs:kotlin.Array<kotlin.String>) returnType:kotlin.Unit
-    VALUE_PARAMETER name:xs index:0 type:kotlin.Array<kotlin.String>
-    BLOCK_BODY
-      TYPE_OP type=kotlin.Unit origin=IMPLICIT_COERCION_TO_UNIT typeOperand=kotlin.Unit
-        CALL 'public final fun useTX <T> (x: T of <root>.useTX, fn: kotlin.Function0<T of <root>.useTX>): T of <root>.useTX declared in <root>' type=java.io.Serializable origin=null
-          <T>: java.io.Serializable
-          x: GET_VAR 'xs: kotlin.Array<kotlin.String> declared in <root>.testWithNullCheck' type=kotlin.Array<kotlin.String> origin=null
-          fn: FUN_EXPR type=kotlin.Function0<java.io.Serializable> origin=LAMBDA
-            FUN LOCAL_FUNCTION_FOR_LAMBDA name:<anonymous> visibility:local modality:FINAL <> () returnType:java.io.Serializable
-              BLOCK_BODY
-                RETURN type=kotlin.Nothing from='local final fun <anonymous> (): java.io.Serializable declared in <root>.testWithNullCheck'
-                  TYPE_OP type=@[EnhancedNullability] kotlin.String origin=IMPLICIT_NOTNULL typeOperand=@[EnhancedNullability] kotlin.String
-                    CALL 'public open fun notNullString (): @[EnhancedNullability] kotlin.String declared in <root>.J' type=@[EnhancedNullability] kotlin.String origin=null

compiler/testData/ir/irText/types/nullChecks/nullCheckOnLambdaResult/nnStringVsTXArray.kt

@@ -1,3 +1,4 @@
+// FIR_IDENTICAL
 // FILE: nnStringVsTXArray.kt
 fun <T> useTX(x: T, fn: () -> T) = fn()
 

compiler/testData/ir/irText/types/nullChecks/nullCheckOnLambdaResult/nnStringVsTXString.fir.txt

@@ -1,21 +0,0 @@
-FILE fqName:<root> fileName:/nnStringVsTXString.kt
-  FUN name:useTX visibility:public modality:FINAL <T> (x:T of <root>.useTX, fn:kotlin.Function0<T of <root>.useTX>) returnType:T of <root>.useTX
-    TYPE_PARAMETER name:T index:0 variance: superTypes:[kotlin.Any?]
-    VALUE_PARAMETER name:x index:0 type:T of <root>.useTX
-    VALUE_PARAMETER name:fn index:1 type:kotlin.Function0<T of <root>.useTX>
-    BLOCK_BODY
-      RETURN type=kotlin.Nothing from='public final fun useTX <T> (x: T of <root>.useTX, fn: kotlin.Function0<T of <root>.useTX>): T of <root>.useTX declared in <root>'
-        CALL 'public abstract fun invoke (): R of kotlin.Function0 [operator] declared in kotlin.Function0' type=T of <root>.useTX origin=INVOKE
-          $this: GET_VAR 'fn: kotlin.Function0<T of <root>.useTX> declared in <root>.useTX' type=kotlin.Function0<T of <root>.useTX> origin=VARIABLE_AS_FUNCTION
-  FUN name:testWithNullCheck visibility:public modality:FINAL <> () returnType:kotlin.Unit
-    BLOCK_BODY
-      TYPE_OP type=kotlin.Unit origin=IMPLICIT_COERCION_TO_UNIT typeOperand=kotlin.Unit
-        CALL 'public final fun useTX <T> (x: T of <root>.useTX, fn: kotlin.Function0<T of <root>.useTX>): T of <root>.useTX declared in <root>' type=kotlin.String origin=null
-          <T>: kotlin.String
-          x: CONST String type=kotlin.String value=""
-          fn: FUN_EXPR type=kotlin.Function0<kotlin.String> origin=LAMBDA
-            FUN LOCAL_FUNCTION_FOR_LAMBDA name:<anonymous> visibility:local modality:FINAL <> () returnType:kotlin.String
-              BLOCK_BODY
-                RETURN type=kotlin.Nothing from='local final fun <anonymous> (): kotlin.String declared in <root>.testWithNullCheck'
-                  TYPE_OP type=@[EnhancedNullability] kotlin.String origin=IMPLICIT_NOTNULL typeOperand=@[EnhancedNullability] kotlin.String
-                    CALL 'public open fun notNullString (): @[EnhancedNullability] kotlin.String declared in <root>.J' type=@[EnhancedNullability] kotlin.String origin=null

compiler/testData/ir/irText/types/nullChecks/nullCheckOnLambdaResult/nnStringVsTXString.kt

@@ -1,3 +1,4 @@
+// FIR_IDENTICAL
 // FILE: nnStringVsTXString.kt
 fun <T> useTX(x: T, fn: () -> T) = fn()