[FIR] Don't create DNN types for flexible simple types

^KT-50788

analysis/low-level-api-fir/tests/org/jetbrains/kotlin/analysis/low/level/api/fir/diagnostic/compiler/based/DiagnosisCompilerFirTestdataTestGenerated.java

@@ -2799,6 +2799,12 @@ public class DiagnosisCompilerFirTestdataTestGenerated extends AbstractDiagnosis
                 runTest("compiler/fir/analysis-tests/testData/resolve/inference/definitelyNotNullIntersectionType.kt");
             }
 
+            @Test
+            @TestMetadata("dnnThrowJavaCall.kt")
+            public void testDnnThrowJavaCall() throws Exception {
+                runTest("compiler/fir/analysis-tests/testData/resolve/inference/dnnThrowJavaCall.kt");
+            }
+
             @Test
             @TestMetadata("elvisAndUnit.kt")
             public void testElvisAndUnit() throws Exception {

compiler/fir/analysis-tests/legacy-fir-tests/tests-gen/org/jetbrains/kotlin/fir/LazyBodyIsNotTouchedTilContractsPhaseTestGenerated.java

@@ -2461,6 +2461,11 @@ public class LazyBodyIsNotTouchedTilContractsPhaseTestGenerated extends Abstract
             runTest("compiler/fir/analysis-tests/testData/resolve/inference/definitelyNotNullIntersectionType.kt");
         }
 
+        @TestMetadata("dnnThrowJavaCall.kt")
+        public void testDnnThrowJavaCall() throws Exception {
+            runTest("compiler/fir/analysis-tests/testData/resolve/inference/dnnThrowJavaCall.kt");
+        }
+
         @TestMetadata("elvisAndUnit.kt")
         public void testElvisAndUnit() throws Exception {
             runTest("compiler/fir/analysis-tests/testData/resolve/inference/elvisAndUnit.kt");

compiler/fir/analysis-tests/testData/resolve/inference/dnnThrowJavaCall.fir.txt

@@ -0,0 +1,4 @@
+FILE: main.kt
+    public final fun getExcludedDirs(project: R|Project|, excludedProjects: R|kotlin/collections/List<Project>|): R|kotlin/collections/List<java/io/File>| {
+        ^getExcludedDirs R|<local>/project|.R|/Project.plugins|.R|/PluginContainer.findPlugin|<R|ft<IdeaPlugin, IdeaPlugin?>|>(<getClass>(Q|IdeaPlugin|).R|kotlin/jvm/java|<R|IdeaPlugin|>)?.{ $subj$.R|/IdeaPlugin.excludeDirs| }?.{ $subj$.R|kotlin/collections/toList|<R|ft<java/io/File, java/io/File?>|>() } ?: R|kotlin/collections/emptyList|<R|java/io/File|>()
+    }

compiler/fir/analysis-tests/testData/resolve/inference/dnnThrowJavaCall.kt

@@ -0,0 +1,37 @@
+// WITH_STDLIB
+// FULL_JDK
+
+// FILE: Plugin.java
+public interface Plugin {}
+
+// FILE: IdeaPlugin.java
+import java.io.File
+import java.util.Set
+
+public interface IdeaPlugin extends Plugin {
+    Set<File> getExcludeDirs()
+}
+
+// FILE: PluginContainer.java
+import javax.annotation.Nullable
+
+public interface PluginContainer {
+    @Nullable
+    <T extends Plugin> T findPlugin(Class<T> type);
+}
+
+// FILE: Project.java
+public interface Project {
+    PluginContainer getPlugins();
+
+    Project getRootProject();
+
+    File getBuildDir();
+}
+
+// FILE: main.kt
+import java.io.File
+
+fun getExcludedDirs(project: Project, excludedProjects: List<Project>): List<File> {
+    return project.plugins.findPlugin(IdeaPlugin::class.java)?.excludeDirs?.toList() ?: emptyList()
+}

compiler/fir/analysis-tests/tests-gen/org/jetbrains/kotlin/test/runners/FirDiagnosticTestGenerated.java

@@ -2799,6 +2799,12 @@ public class FirDiagnosticTestGenerated extends AbstractFirDiagnosticTest {
                 runTest("compiler/fir/analysis-tests/testData/resolve/inference/definitelyNotNullIntersectionType.kt");
             }
 
+            @Test
+            @TestMetadata("dnnThrowJavaCall.kt")
+            public void testDnnThrowJavaCall() throws Exception {
+                runTest("compiler/fir/analysis-tests/testData/resolve/inference/dnnThrowJavaCall.kt");
+            }
+
             @Test
             @TestMetadata("elvisAndUnit.kt")
             public void testElvisAndUnit() throws Exception {

compiler/fir/analysis-tests/tests-gen/org/jetbrains/kotlin/test/runners/FirDiagnosticsWithLightTreeTestGenerated.java

@@ -2799,6 +2799,12 @@ public class FirDiagnosticsWithLightTreeTestGenerated extends AbstractFirDiagnos
                 runTest("compiler/fir/analysis-tests/testData/resolve/inference/definitelyNotNullIntersectionType.kt");
             }
 
+            @Test
+            @TestMetadata("dnnThrowJavaCall.kt")
+            public void testDnnThrowJavaCall() throws Exception {
+                runTest("compiler/fir/analysis-tests/testData/resolve/inference/dnnThrowJavaCall.kt");
+            }
+
             @Test
             @TestMetadata("elvisAndUnit.kt")
             public void testElvisAndUnit() throws Exception {

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

@@ -53,17 +53,19 @@ fun ConeInferenceContext.intersectTypesOrNull(types: List<ConeKotlinType>): Cone
 fun TypeCheckerProviderContext.equalTypes(a: ConeKotlinType, b: ConeKotlinType): Boolean =
     AbstractTypeChecker.equalTypes(this, a, b)
 
-private fun ConeTypeContext.makesSenseToBeDefinitelyNotNull(type: ConeKotlinType): Boolean = when (type) {
+private fun ConeTypeContext.makesSenseToBeDefinitelyNotNull(originalType: ConeKotlinType): Boolean {
-    is ConeTypeParameterType -> type.isNullableType()
+    return when (val type = originalType.lowerBoundIfFlexible()) {
-    // Actually, this branch should work for type parameters as well, but it breaks some cases. See KT-40114.
+        is ConeTypeParameterType -> type.isNullableType()
-    // Basically, if we have `T : X..X?`, then `T <: Any` but we still have `T` != `T & Any`.
+        // Actually, this branch should work for type parameters as well, but it breaks some cases. See KT-40114.
-    is ConeTypeVariableType, is ConeCapturedType, is ConeFlexibleType ->
+        // Basically, if we have `T : X..X?`, then `T <: Any` but we still have `T` != `T & Any`.
-        !AbstractNullabilityChecker.isSubtypeOfAny(
+        is ConeTypeVariableType, is ConeCapturedType -> {
-            newTypeCheckerState(errorTypesEqualToAnything = false, stubTypesEqualToAnything = false), type
+            !AbstractNullabilityChecker.isSubtypeOfAny(
-        )
+                newTypeCheckerState(errorTypesEqualToAnything = false, stubTypesEqualToAnything = false), type
-    // For all other types `T & Any` is the same as `T` without a question mark.
+            )
-    // TODO: not true for flexible types.
+        }
-    else -> false
+        // For all other types `T & Any` is the same as `T` without a question mark.
+        else -> false
+    }
 }
 
 // TODO: leave only one of `create` and `makeConeTypeDefinitelyNotNullOrNotNull`

compiler/testData/diagnostics/tests/inference/builderInference/stubTypes/commonSuperTypeContravariant.fir.kt

@@ -77,8 +77,8 @@ fun test() {
         <!DEBUG_INFO_EXPRESSION_TYPE("kotlin.String?")!>select2(Test.foo(get()), getIn())<!>
         <!DEBUG_INFO_EXPRESSION_TYPE("kotlin.String?")!>select3(get(), getIn())<!>
         <!DEBUG_INFO_EXPRESSION_TYPE("kotlin.String?")!>select3(get(), Test.foo(getIn()))<!>
-        <!DEBUG_INFO_EXPRESSION_TYPE("kotlin.String")!>select3(Test.foo(get()), Test.foo(getIn()))<!>
+        <!DEBUG_INFO_EXPRESSION_TYPE("kotlin.String?")!>select3(Test.foo(get()), Test.foo(getIn()))<!>
-        <!DEBUG_INFO_EXPRESSION_TYPE("kotlin.String")!>select3(Test.foo(get()), getIn())<!>
+        <!DEBUG_INFO_EXPRESSION_TYPE("kotlin.String?")!>select3(Test.foo(get()), getIn())<!>
         ""
     }
 }