K2: support ForbidInferringTypeVariablesIntoEmptyIntersection on/off

analysis/analysis-api-fir/src/org/jetbrains/kotlin/analysis/api/fir/diagnostics/KtFirDataClassConverters.kt

@@ -2224,8 +2224,20 @@ internal val KT_DIAGNOSTIC_CONVERTER = KtDiagnosticConverterBuilder.buildConvert
             token,
         )
     }
-    add(FirErrors.INFERRED_TYPE_VARIABLE_INTO_EMPTY_INTERSECTION) { firDiagnostic ->
+    add(FirErrors.INFERRED_TYPE_VARIABLE_INTO_EMPTY_INTERSECTION.errorFactory) { firDiagnostic ->
-        InferredTypeVariableIntoEmptyIntersectionImpl(
+        InferredTypeVariableIntoEmptyIntersectionErrorImpl(
+            firDiagnostic.a,
+            firDiagnostic.b.map { coneKotlinType ->
+                firSymbolBuilder.typeBuilder.buildKtType(coneKotlinType)
+            },
+            firDiagnostic.c,
+            firDiagnostic.d,
+            firDiagnostic as KtPsiDiagnostic,
+            token,
+        )
+    }
+    add(FirErrors.INFERRED_TYPE_VARIABLE_INTO_EMPTY_INTERSECTION.warningFactory) { firDiagnostic ->
+        InferredTypeVariableIntoEmptyIntersectionWarningImpl(
             firDiagnostic.a,
             firDiagnostic.b.map { coneKotlinType ->
                 firSymbolBuilder.typeBuilder.buildKtType(coneKotlinType)

analysis/analysis-api-fir/src/org/jetbrains/kotlin/analysis/api/fir/diagnostics/KtFirDiagnostics.kt

@@ -1579,8 +1579,16 @@ sealed class KtFirDiagnostic<PSI : PsiElement> : KtDiagnosticWithPsi<PSI> {
         abstract val kotlinClass: FqName
     }
 
-    abstract class InferredTypeVariableIntoEmptyIntersection : KtFirDiagnostic<PsiElement>() {
+    abstract class InferredTypeVariableIntoEmptyIntersectionError : KtFirDiagnostic<PsiElement>() {
-        override val diagnosticClass get() = InferredTypeVariableIntoEmptyIntersection::class
+        override val diagnosticClass get() = InferredTypeVariableIntoEmptyIntersectionError::class
+        abstract val typeVariableDescription: String
+        abstract val incompatibleTypes: List<KtType>
+        abstract val description: String
+        abstract val causingTypes: String
+    }
+
+    abstract class InferredTypeVariableIntoEmptyIntersectionWarning : KtFirDiagnostic<PsiElement>() {
+        override val diagnosticClass get() = InferredTypeVariableIntoEmptyIntersectionWarning::class
         abstract val typeVariableDescription: String
         abstract val incompatibleTypes: List<KtType>
         abstract val description: String

analysis/analysis-api-fir/src/org/jetbrains/kotlin/analysis/api/fir/diagnostics/KtFirDiagnosticsImpl.kt

@@ -1899,14 +1899,23 @@ internal class PlatformClassMappedToKotlinImpl(
     override val token: KtLifetimeToken,
 ) : KtFirDiagnostic.PlatformClassMappedToKotlin(), KtAbstractFirDiagnostic<PsiElement>
 
-internal class InferredTypeVariableIntoEmptyIntersectionImpl(
+internal class InferredTypeVariableIntoEmptyIntersectionErrorImpl(
     override val typeVariableDescription: String,
     override val incompatibleTypes: List<KtType>,
     override val description: String,
     override val causingTypes: String,
     override val firDiagnostic: KtPsiDiagnostic,
     override val token: KtLifetimeToken,
-) : KtFirDiagnostic.InferredTypeVariableIntoEmptyIntersection(), KtAbstractFirDiagnostic<PsiElement>
+) : KtFirDiagnostic.InferredTypeVariableIntoEmptyIntersectionError(), KtAbstractFirDiagnostic<PsiElement>
+
+internal class InferredTypeVariableIntoEmptyIntersectionWarningImpl(
+    override val typeVariableDescription: String,
+    override val incompatibleTypes: List<KtType>,
+    override val description: String,
+    override val causingTypes: String,
+    override val firDiagnostic: KtPsiDiagnostic,
+    override val token: KtLifetimeToken,
+) : KtFirDiagnostic.InferredTypeVariableIntoEmptyIntersectionWarning(), KtAbstractFirDiagnostic<PsiElement>
 
 internal class InferredTypeVariableIntoPossibleEmptyIntersectionImpl(
     override val typeVariableDescription: String,

compiler/fir/checkers/checkers-component-generator/src/org/jetbrains/kotlin/fir/checkers/generator/diagnostics/FirDiagnosticsList.kt

@@ -737,7 +737,9 @@ object DIAGNOSTICS_LIST : DiagnosticList("FirErrors") {
             parameter<FqName>("kotlinClass")
         }
 
-        val INFERRED_TYPE_VARIABLE_INTO_EMPTY_INTERSECTION by error<PsiElement> {
+        val INFERRED_TYPE_VARIABLE_INTO_EMPTY_INTERSECTION by deprecationError<PsiElement>(
+            LanguageFeature.ForbidInferringTypeVariablesIntoEmptyIntersection
+        ) {
             parameter<String>("typeVariableDescription")
             parameter<Collection<ConeKotlinType>>("incompatibleTypes")
             parameter<String>("description")

compiler/fir/checkers/gen/org/jetbrains/kotlin/fir/analysis/diagnostics/FirErrors.kt

@@ -12,6 +12,7 @@ import org.jetbrains.kotlin.builtins.functions.FunctionTypeKind
 import org.jetbrains.kotlin.config.ApiVersion
 import org.jetbrains.kotlin.config.LanguageFeature
 import org.jetbrains.kotlin.config.LanguageFeature.ForbidExposingTypesInPrimaryConstructorProperties
+import org.jetbrains.kotlin.config.LanguageFeature.ForbidInferringTypeVariablesIntoEmptyIntersection
 import org.jetbrains.kotlin.config.LanguageFeature.ForbidUsingExtensionPropertyTypeParameterInDelegate
 import org.jetbrains.kotlin.config.LanguageFeature.ModifierNonBuiltinSuspendFunError
 import org.jetbrains.kotlin.config.LanguageFeature.ProhibitAssigningSingleElementsToVarargsInNamedForm
@@ -433,7 +434,7 @@ object FirErrors {
     val SMARTCAST_IMPOSSIBLE by error4<KtExpression, ConeKotlinType, FirExpression, String, Boolean>()
     val REDUNDANT_NULLABLE by warning0<KtTypeReference>(SourceElementPositioningStrategies.REDUNDANT_NULLABLE)
     val PLATFORM_CLASS_MAPPED_TO_KOTLIN by warning1<PsiElement, FqName>(SourceElementPositioningStrategies.REFERENCED_NAME_BY_QUALIFIED)
-    val INFERRED_TYPE_VARIABLE_INTO_EMPTY_INTERSECTION by error4<PsiElement, String, Collection<ConeKotlinType>, String, String>()
+    val INFERRED_TYPE_VARIABLE_INTO_EMPTY_INTERSECTION by deprecationError4<PsiElement, String, Collection<ConeKotlinType>, String, String>(ForbidInferringTypeVariablesIntoEmptyIntersection)
     val INFERRED_TYPE_VARIABLE_INTO_POSSIBLE_EMPTY_INTERSECTION by warning4<PsiElement, String, Collection<ConeKotlinType>, String, String>()
     val INCORRECT_LEFT_COMPONENT_OF_INTERSECTION by error0<KtTypeReference>()
     val INCORRECT_RIGHT_COMPONENT_OF_INTERSECTION by error0<KtTypeReference>()

compiler/fir/checkers/src/org/jetbrains/kotlin/fir/analysis/diagnostics/coneDiagnosticToFirDiagnostic.kt

@@ -292,8 +292,13 @@ private fun mapInapplicableCandidateError(
                 )
             }
 
-            is InferredEmptyIntersectionDiagnostic -> reportInferredIntoEmptyIntersectionError(
+            is InferredEmptyIntersectionDiagnostic -> reportInferredIntoEmptyIntersection(
-                source, rootCause.typeVariable, rootCause.incompatibleTypes, rootCause.causingTypes, rootCause.kind
+                source,
+                rootCause.typeVariable,
+                rootCause.incompatibleTypes,
+                rootCause.causingTypes,
+                rootCause.kind,
+                isError = rootCause.isError
             )
 
             else -> genericDiagnostic
@@ -434,12 +439,13 @@ private fun ConstraintSystemError.toDiagnostic(
 
         is InferredEmptyIntersection -> {
             @Suppress("UNCHECKED_CAST")
-            reportInferredIntoEmptyIntersectionError(
+            reportInferredIntoEmptyIntersection(
                 source,
                 typeVariable as ConeTypeVariable,
                 incompatibleTypes as Collection<ConeKotlinType>,
                 causingTypes as Collection<ConeKotlinType>,
-                kind
+                kind,
+                this is InferredEmptyIntersectionError,
             )
         }
 
@@ -454,20 +460,24 @@ private fun ConstraintSystemError.toDiagnostic(
     }
 }
 
-private fun reportInferredIntoEmptyIntersectionError(
+private fun reportInferredIntoEmptyIntersection(
     source: KtSourceElement,
     typeVariable: ConeTypeVariable,
     incompatibleTypes: Collection<ConeKotlinType>,
     causingTypes: Collection<ConeKotlinType>,
-    kind: EmptyIntersectionTypeKind
+    kind: EmptyIntersectionTypeKind,
+    isError: Boolean
 ): KtDiagnostic? {
     val typeVariableText =
         (typeVariable.typeConstructor.originalTypeParameter as? ConeTypeParameterLookupTag)?.name?.asString()
             ?: typeVariable.toString()
     val causingTypesText = if (incompatibleTypes == causingTypes) "" else ": ${causingTypes.joinToString()}"
     val factory =
-        if (kind.isDefinitelyEmpty) FirErrors.INFERRED_TYPE_VARIABLE_INTO_EMPTY_INTERSECTION
+        when {
-        else FirErrors.INFERRED_TYPE_VARIABLE_INTO_POSSIBLE_EMPTY_INTERSECTION
+            !kind.isDefinitelyEmpty -> FirErrors.INFERRED_TYPE_VARIABLE_INTO_POSSIBLE_EMPTY_INTERSECTION
+            isError -> FirErrors.INFERRED_TYPE_VARIABLE_INTO_EMPTY_INTERSECTION.errorFactory
+            else -> FirErrors.INFERRED_TYPE_VARIABLE_INTO_EMPTY_INTERSECTION.warningFactory
+        }
 
     return factory.createOn(source, typeVariableText, incompatibleTypes, kind.description, causingTypesText)
 }

compiler/fir/resolve/src/org/jetbrains/kotlin/fir/resolve/calls/ResolutionStages.kt

@@ -597,7 +597,10 @@ internal object CheckIncompatibleTypeVariableUpperBounds : ResolutionStage() {
                         upperTypes as List<ConeKotlinType>,
                         emptyIntersectionTypeInfo.casingTypes.toList() as List<ConeKotlinType>,
                         variableWithConstraints.typeVariable as ConeTypeVariable,
-                        emptyIntersectionTypeInfo.kind
+                        emptyIntersectionTypeInfo.kind,
+                        isError = context.session.languageVersionSettings.supportsFeature(
+                            LanguageFeature.ForbidInferringTypeVariablesIntoEmptyIntersection
+                        )
                     )
                 )
             }

compiler/fir/semantics/src/org/jetbrains/kotlin/fir/resolve/calls/ResolutionDiagnostic.kt

@@ -33,7 +33,8 @@ class InferredEmptyIntersectionDiagnostic(
     val incompatibleTypes: Collection<ConeKotlinType>,
     val causingTypes: Collection<ConeKotlinType>,
     val typeVariable: ConeTypeVariable,
-    val kind: EmptyIntersectionTypeKind
+    val kind: EmptyIntersectionTypeKind,
+    val isError: Boolean
 ) : ResolutionDiagnostic(INAPPLICABLE)
 
 class TooManyArguments(

compiler/testData/diagnostics/tests/inference/coercionToUnit/afterBareReturn.fir.kt

@@ -27,7 +27,7 @@ fun test3() = run {
     incompatibleI() // ? either uninferred T or error (Unit </: I)
 }
 
-fun test4() = <!INFERRED_TYPE_VARIABLE_INTO_EMPTY_INTERSECTION!>run<!> {
+fun test4() = <!INFERRED_TYPE_VARIABLE_INTO_EMPTY_INTERSECTION_WARNING!>run<!> {
     if (p) return@run
     incompatibleC() // ? either uninferred T or error (Unit </: C)
 }

compiler/testData/diagnostics/tests/inference/coercionToUnit/coercionToUnitWithNothingType.fir.kt

@@ -47,7 +47,7 @@ fun test(i: Inv<Nothing>, iUnit: Inv<Unit>) {
 
     if (iUnit is String) {
         launch {
-            run(A.<!INFERRED_TYPE_VARIABLE_INTO_EMPTY_INTERSECTION!>flexible<!>(iUnit)) { 42 }
+            run(A.<!INFERRED_TYPE_VARIABLE_INTO_EMPTY_INTERSECTION_WARNING!>flexible<!>(iUnit)) { 42 }
         }
     }
 }

compiler/testData/diagnostics/tests/inference/emptyIntersectionTypes/compatibilityResolveWhenVariableHasComplexIntersectionType.fir.kt

@@ -1,37 +0,0 @@
-// !DIAGNOSTICS: -UNUSED_PARAMETER -UNUSED_EXPRESSION
-
-abstract class Foo<T>
-
-abstract class Bar<T> : Foo<T>(), Comparable<Bar<T>>
-
-object Scope {
-    fun <T : Comparable<T>, S : T> greater(x: Bar<in S>, other: Foo<T>) {}
-
-    object Nested {
-        fun <T : Comparable<T>, S : T> greater(x: Bar<in S>, t: T) {}
-
-        fun test(b: Bar<Long>) {
-            <!DEBUG_INFO_CALL("fqName: Scope.greater; typeCall: function")!>greater(b, b)<!>
-        }
-    }
-}
-
-object OnlyOne {
-    fun <T : Comparable<T>, S : T> greater(x: Bar<in S>, t: T) {}
-
-    fun test(b: Bar<Long>) {
-        <!DEBUG_INFO_CALL("fqName: OnlyOne.greater; typeCall: function")!><!INFERRED_TYPE_VARIABLE_INTO_EMPTY_INTERSECTION!>greater<!>(b, b)<!>
-    }
-}
-
-object GoodOldCandidate {
-    fun <T : Comparable<T>, S : T> greater(x: Bar<in S>, t: T) {}
-
-    object Nested {
-        fun <T : Comparable<T>, S : T> greater(x: Bar<in S>, other: Foo<T>) {}
-
-        fun test(b: Bar<Long>) {
-            <!DEBUG_INFO_CALL("fqName: GoodOldCandidate.Nested.greater; typeCall: function")!>greater(b, b)<!>
-        }
-    }
-}

compiler/testData/diagnostics/tests/inference/emptyIntersectionTypes/compatibilityResolveWhenVariableHasComplexIntersectionType.kt

@@ -1,3 +1,4 @@
+// FIR_IDENTICAL
 // !DIAGNOSTICS: -UNUSED_PARAMETER -UNUSED_EXPRESSION
 
 abstract class Foo<T>

compiler/testData/diagnostics/tests/inference/emptyIntersectionTypes/kt45461.fir.kt

@@ -1,11 +0,0 @@
-// RENDER_DIAGNOSTICS_FULL_TEXT
-class Foo<T>
-
-class Bar<T> {
-    fun <S : T> takeFoo(foo: Foo<in S>) {}
-}
-
-fun main() {
-    val foo = Foo<Int>()
-    Bar<String>().<!INFERRED_TYPE_VARIABLE_INTO_EMPTY_INTERSECTION!>takeFoo<!>(foo) // error in 1.3.72, no error in 1.4.31
-}

compiler/testData/diagnostics/tests/inference/emptyIntersectionTypes/kt45461.kt

@@ -1,3 +1,4 @@
+// FIR_IDENTICAL
 // RENDER_DIAGNOSTICS_FULL_TEXT
 class Foo<T>
 

compiler/testData/diagnostics/tests/inference/emptyIntersectionTypes/kt45461_12.fir.kt

@@ -1,13 +0,0 @@
-// RENDER_DIAGNOSTICS_FULL_TEXT
-class Foo<T>
-
-class Bar<T> {
-    fun <S : T> takeFoo(foo: Foo<in S>) {}
-}
-
-interface A
-
-fun <K : L, L : N, N> main() where N: A, N: Number {
-    val foo = Foo<K>()
-    Bar<String>().<!INFERRED_TYPE_VARIABLE_INTO_EMPTY_INTERSECTION!>takeFoo<!>(foo) // error in 1.3.72, no error in 1.4.31
-}

compiler/testData/diagnostics/tests/inference/emptyIntersectionTypes/kt45461_12.kt

@@ -1,3 +1,4 @@
+// FIR_IDENTICAL
 // RENDER_DIAGNOSTICS_FULL_TEXT
 class Foo<T>
 

compiler/testData/diagnostics/tests/inference/emptyIntersectionTypes/kt45461_2.fir.kt

@@ -1,11 +0,0 @@
-// RENDER_DIAGNOSTICS_FULL_TEXT
-class Foo<T>
-
-class Bar<T> {
-    fun <S : T> takeFoo(foo: Foo<in S>) {}
-}
-
-fun <K : <!FINAL_UPPER_BOUND!>Int<!>> main() {
-    val foo = Foo<K>()
-    Bar<String>().<!INFERRED_TYPE_VARIABLE_INTO_EMPTY_INTERSECTION!>takeFoo<!>(foo) // error in 1.3.72, no error in 1.4.31
-}

compiler/testData/diagnostics/tests/inference/emptyIntersectionTypes/kt45461_2.kt

@@ -1,3 +1,4 @@
+// FIR_IDENTICAL
 // RENDER_DIAGNOSTICS_FULL_TEXT
 class Foo<T>
 

compiler/testData/diagnostics/tests/inference/emptyIntersectionTypes/kt45461_25.fir.kt

@@ -8,5 +8,5 @@ class Bar<T> {
 
 fun <K : L, L : N, N: <!FINAL_UPPER_BOUND!>Int<!>> main() {
     val foo = Foo<K>()
-    val x: Float = Bar<String>().<!INFERRED_TYPE_VARIABLE_INTO_EMPTY_INTERSECTION("S; kotlin/String, K; multiple incompatible classes; : kotlin/String, kotlin/Int")!>takeFoo<!>(foo) // error in 1.3.72, no error in 1.4.31
+    val x: Float = Bar<String>().<!INFERRED_TYPE_VARIABLE_INTO_EMPTY_INTERSECTION_ERROR("S; kotlin/String, K; multiple incompatible classes; : kotlin/String, kotlin/Int")!>takeFoo<!>(foo) // error in 1.3.72, no error in 1.4.31
 }

compiler/testData/diagnostics/tests/inference/emptyIntersectionTypes/kt45461_5.fir.kt

@@ -1,11 +0,0 @@
-// RENDER_DIAGNOSTICS_FULL_TEXT
-class Foo<T>
-
-class Bar<T> {
-    fun <S : T> takeFoo(foo: Foo<in S>) {}
-}
-
-fun <K : L, L : N, N: Number> main() {
-    val foo = Foo<K>()
-    Bar<String>().<!INFERRED_TYPE_VARIABLE_INTO_EMPTY_INTERSECTION!>takeFoo<!>(foo) // error in 1.3.72, no error in 1.4.31
-}

compiler/testData/diagnostics/tests/inference/emptyIntersectionTypes/kt45461_5.kt

@@ -1,3 +1,4 @@
+// FIR_IDENTICAL
 // RENDER_DIAGNOSTICS_FULL_TEXT
 class Foo<T>
 

compiler/testData/diagnostics/tests/inference/emptyIntersectionTypes/kt48765.fir.kt

@@ -1,17 +0,0 @@
-// RENDER_DIAGNOSTICS_FULL_TEXT
-open class A<T1, T2> {}
-class B {
-    fun <T1: Number, T2: A<Float, T1>> foo(x1: T2, x2: T1) {}
-}
-class C<T: D, T2>(val x: T, val y: T2) {
-    fun test() {
-        B().<!INFERRED_TYPE_VARIABLE_INTO_EMPTY_INTERSECTION!>foo<!>(x, foo())
-    }
-}
-open class D: A<Float, Number>()
-fun <T: <!FINAL_UPPER_BOUND!>String<!>> foo(): T  {
-    return "" <!UNCHECKED_CAST!>as T<!> // this cast is safe because String is final.
-}
-fun main() {
-    C(D(), 10.5).test()
-}

compiler/testData/diagnostics/tests/inference/emptyIntersectionTypes/kt48765.kt

@@ -1,3 +1,4 @@
+// FIR_IDENTICAL
 // RENDER_DIAGNOSTICS_FULL_TEXT
 open class A<T1, T2> {}
 class B {

compiler/testData/diagnostics/tests/inference/emptyIntersectionTypes/kt48935_3.fir.kt

@@ -1,11 +0,0 @@
-open class Base
-open class DoesNotImplementBase
-
-fun <T, V> exampleGenericFunction(func: V) where T: Base, V: (T) -> Unit {
-
-}
-
-fun main() {
-    val func: (DoesNotImplementBase) -> Unit = { }
-    <!INFERRED_TYPE_VARIABLE_INTO_EMPTY_INTERSECTION!>exampleGenericFunction<!>(func) // expected this to be a compilation error as the T: Base constraint should not be satisfied
-}

compiler/testData/diagnostics/tests/inference/emptyIntersectionTypes/kt48935_3.kt

@@ -1,3 +1,4 @@
+// FIR_IDENTICAL
 open class Base
 open class DoesNotImplementBase
 

compiler/testData/diagnostics/tests/inference/emptyIntersectionTypes/kt48935_4.fir.kt

@@ -1,11 +0,0 @@
-open class Base
-class DoesNotImplementBase
-
-fun <T, V> exampleGenericFunction(func: V) where T: Base, V: (T) -> Unit {
-
-}
-
-fun main() {
-    val func: (DoesNotImplementBase) -> Unit = { }
-    <!INFERRED_TYPE_VARIABLE_INTO_EMPTY_INTERSECTION!>exampleGenericFunction<!>(func) // expected this to be a compilation error as the T: Base constraint should not be satisfied
-}

compiler/testData/diagnostics/tests/inference/emptyIntersectionTypes/kt48935_4.kt

@@ -1,3 +1,4 @@
+// FIR_IDENTICAL
 open class Base
 class DoesNotImplementBase
 

compiler/testData/diagnostics/tests/inference/emptyIntersectionTypes/kt48987.fir.kt

@@ -5,7 +5,7 @@ fun box(): String {
     return try {
         val range1 = 0..1
         range1 <!CAST_NEVER_SUCCEEDS!>as<!> List<Double>
-        range1.<!INFERRED_TYPE_VARIABLE_INTO_EMPTY_INTERSECTION!>joinToString<!> { "" }
+        range1.<!INFERRED_TYPE_VARIABLE_INTO_EMPTY_INTERSECTION_WARNING!>joinToString<!> { "" }
     } catch (e: java.lang.ClassCastException) {
         "OK"
     }

compiler/testData/diagnostics/tests/inference/emptyIntersectionTypes/kt49661.fir.kt

@@ -1,11 +0,0 @@
-// RENDER_DIAGNOSTICS_FULL_TEXT
-open class Foo
-inline fun <reified T : Foo> g(): T? = null
-
-inline fun <R> f(block: ()->R?): R? {
-    return block()
-}
-
-fun main() {
-    <!INFERRED_TYPE_VARIABLE_INTO_EMPTY_INTERSECTION!>f<!><Int> { g() }
-}

compiler/testData/diagnostics/tests/inference/emptyIntersectionTypes/kt49661.kt

@@ -1,3 +1,4 @@
+// FIR_IDENTICAL
 // RENDER_DIAGNOSTICS_FULL_TEXT
 open class Foo
 inline fun <reified T : Foo> g(): T? = null

compiler/testData/diagnostics/tests/inference/emptyIntersectionTypes/nullableEmptyIntersection.fir.kt

@@ -1,7 +0,0 @@
-fun <T : <!FINAL_UPPER_BOUND!>String<!>> g(): T? = null
-
-fun <R> f(block: () -> R?): R? = block()
-
-fun main() {
-    <!INFERRED_TYPE_VARIABLE_INTO_EMPTY_INTERSECTION!>f<!><Int> { g() /* OK, g() is inferred into {Int & String}? */ }
-}

compiler/testData/diagnostics/tests/inference/emptyIntersectionTypes/nullableEmptyIntersection.kt

@@ -1,3 +1,4 @@
+// FIR_IDENTICAL
 fun <T : <!FINAL_UPPER_BOUND!>String<!>> g(): T? = null
 
 fun <R> f(block: () -> R?): R? = block()

compiler/testData/diagnostics/tests/inference/emptyIntersectionTypes/selectFromCovariantAndContravariantTypes.fir.kt

@@ -1,20 +0,0 @@
-// RENDER_DIAGNOSTICS_FULL_TEXT
-// !DIAGNOSTICS: -UNUSED_PARAMETER
-
-class In<in T>
-class Out<out T>
-
-class A
-class B
-
-fun <K> select(x: K, y: K): K = x
-fun <V> genericIn(x: In<V>) {}
-fun <V> genericOut(x: Out<V>) {}
-
-fun test1(a: In<A>, b: In<B>) {
-    <!INFERRED_TYPE_VARIABLE_INTO_EMPTY_INTERSECTION!>genericIn<!>(select(a, b))
-}
-
-fun test2(a: Out<A>, b: Out<B>) {
-    genericOut(select(a, b))
-}

compiler/testData/diagnostics/tests/inference/emptyIntersectionTypes/selectFromCovariantAndContravariantTypes.kt

@@ -1,3 +1,4 @@
+// FIR_IDENTICAL
 // RENDER_DIAGNOSTICS_FULL_TEXT
 // !DIAGNOSTICS: -UNUSED_PARAMETER
 

compiler/testData/diagnostics/tests/typeParameters/dontIntersectUpperBoundWithExpectedType.fir.kt

@@ -9,7 +9,7 @@ fun <T : Foo> foo(): T? {
 }
 
 fun main() {
-    val a: Bar? = <!DEBUG_INFO_EXPRESSION_TYPE("Foo? & Bar?")!><!INFERRED_TYPE_VARIABLE_INTO_EMPTY_INTERSECTION!>foo<!>()<!>
+    val a: Bar? = <!DEBUG_INFO_EXPRESSION_TYPE("Foo? & Bar?")!><!INFERRED_TYPE_VARIABLE_INTO_EMPTY_INTERSECTION_WARNING!>foo<!>()<!>
 }
 
 

compiler/testData/diagnostics/tests/typeParameters/kt46186.fir.kt

@@ -39,7 +39,7 @@ inline fun <reified T> findViewById10(): T where T: View3, T: View5 = null as T
 fun test10(): I = findViewById10()
 
 fun <T: View2> findViewById11(): T = null as T
-fun test11(): View4 = <!INFERRED_TYPE_VARIABLE_INTO_EMPTY_INTERSECTION!>findViewById11<!>()
+fun test11(): View4 = <!INFERRED_TYPE_VARIABLE_INTO_EMPTY_INTERSECTION_WARNING!>findViewById11<!>()
 
 object Obj {
     fun <T: I> findViewById1(): T = null as T
@@ -73,7 +73,7 @@ object Obj {
     fun test10(): View1 = findViewById10()
 
     fun <T: View2> findViewById11(): T = null as T
-    fun test11(): View4 = <!INFERRED_TYPE_VARIABLE_INTO_EMPTY_INTERSECTION!>findViewById11<!>()
+    fun test11(): View4 = <!INFERRED_TYPE_VARIABLE_INTO_EMPTY_INTERSECTION_WARNING!>findViewById11<!>()
 }
 
 interface A

compiler/testData/diagnostics/tests/when/TypeParameterError.fir.kt

@@ -1,25 +0,0 @@
-// !LANGUAGE: +ForbidInferringTypeVariablesIntoEmptyIntersection
-// FILE: ObjectNode.java
-
-public interface ObjectNode {
-    <T extends JsonNode> T set(String fieldName, JsonNode value);
-}
-
-// FILE: JsonNode.java
-
-public class JsonNode
-
-// FILE: test.kt
-
-interface JsonObject
-class SomeJsonObject() : JsonObject
-
-fun String.put(value: JsonObject?, node: ObjectNode) {
-    <!INFERRED_TYPE_VARIABLE_INTO_EMPTY_INTERSECTION!>when (value) {
-        null -> node.set(this, null)
-        is SomeJsonObject -> Unit
-        else -> TODO()
-    }<!>
-}
-
-fun TODO(): Nothing = null!!

compiler/testData/diagnostics/tests/when/TypeParameterError.kt

@@ -1,3 +1,4 @@
+// FIR_IDENTICAL
 // !LANGUAGE: +ForbidInferringTypeVariablesIntoEmptyIntersection
 // FILE: ObjectNode.java
 

compiler/testData/diagnostics/tests/when/TypeParameterWarning.fir.kt

@@ -1,25 +0,0 @@
-// !LANGUAGE: -ForbidInferringTypeVariablesIntoEmptyIntersection
-// FILE: ObjectNode.java
-
-public interface ObjectNode {
-    <T extends JsonNode> T set(String fieldName, JsonNode value);
-}
-
-// FILE: JsonNode.java
-
-public class JsonNode
-
-// FILE: test.kt
-
-interface JsonObject
-class SomeJsonObject() : JsonObject
-
-fun String.put(value: JsonObject?, node: ObjectNode) {
-    <!INFERRED_TYPE_VARIABLE_INTO_EMPTY_INTERSECTION!>when (value) {
-        null -> node.set(this, null)
-        is SomeJsonObject -> Unit
-        else -> TODO()
-    }<!>
-}
-
-fun TODO(): Nothing = null!!

compiler/testData/diagnostics/tests/when/TypeParameterWarning.kt

@@ -1,3 +1,4 @@
+// FIR_IDENTICAL
 // !LANGUAGE: -ForbidInferringTypeVariablesIntoEmptyIntersection
 // FILE: ObjectNode.java
 

compiler/testData/diagnostics/testsWithStdLib/greater.fir.kt

@@ -1,12 +0,0 @@
-class Expression<T>(val x: T)
-
-class GreaterOp(val expr1: Expression<*>, val expr2: Expression<*>)
-
-fun <T : Comparable<T>, S : T?> Expression<in S>.greater(other: T): GreaterOp =
-    GreaterOp(this, Expression(other))
-
-fun foo(countExpr: Expression<Long>) {
-    countExpr.greater(0)
-    countExpr.<!INFERRED_TYPE_VARIABLE_INTO_EMPTY_INTERSECTION!>greater<!>("0")
-    countExpr.greater<String, Nothing>("0")
-}

compiler/testData/diagnostics/testsWithStdLib/greater.kt

@@ -1,3 +1,4 @@
+// FIR_IDENTICAL
 class Expression<T>(val x: T)
 
 class GreaterOp(val expr1: Expression<*>, val expr2: Expression<*>)

compiler/testData/diagnostics/testsWithStdLib/inference/annotationsForResolve/exactAnnotation.fir.kt

@@ -7,5 +7,5 @@ fun test1(l: List<Number>) {
 
     val i: Int = l.firstTyped()
 
-    val s: String = l.<!INFERRED_TYPE_VARIABLE_INTO_EMPTY_INTERSECTION!>firstTyped<!>()
+    val s: String = l.<!INFERRED_TYPE_VARIABLE_INTO_EMPTY_INTERSECTION_WARNING!>firstTyped<!>()
 }