FE: force flexibility on unannotated ?

TODO: unify this code with FIR

 #KT-48515 Fixed

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

@@ -714,6 +714,12 @@ public class FirOldFrontendForeignAnnotationsCompiledJavaTestGenerated extends A
                     runTest("compiler/testData/diagnostics/foreignAnnotationsTests/java8Tests/jspecify/strictMode/TypeParameterBounds.kt");
                 }
 
+                @Test
+                @TestMetadata("UnannotatedWildcard.kt")
+                public void testUnannotatedWildcard() throws Exception {
+                    runTest("compiler/testData/diagnostics/foreignAnnotationsTests/java8Tests/jspecify/strictMode/UnannotatedWildcard.kt");
+                }
+
                 @Test
                 @TestMetadata("WildcardsWithDefault.kt")
                 public void testWildcardsWithDefault() throws Exception {
@@ -796,6 +802,12 @@ public class FirOldFrontendForeignAnnotationsCompiledJavaTestGenerated extends A
                     runTest("compiler/testData/diagnostics/foreignAnnotationsTests/java8Tests/jspecify/warnMode/TypeParameterBounds.kt");
                 }
 
+                @Test
+                @TestMetadata("UnannotatedWildcard.kt")
+                public void testUnannotatedWildcard() throws Exception {
+                    runTest("compiler/testData/diagnostics/foreignAnnotationsTests/java8Tests/jspecify/warnMode/UnannotatedWildcard.kt");
+                }
+
                 @Test
                 @TestMetadata("WildcardsWithDefault.kt")
                 public void testWildcardsWithDefault() throws Exception {

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

@@ -714,6 +714,12 @@ public class FirOldFrontendForeignAnnotationsCompiledJavaWithPsiClassReadingTest
                     runTest("compiler/testData/diagnostics/foreignAnnotationsTests/java8Tests/jspecify/strictMode/TypeParameterBounds.kt");
                 }
 
+                @Test
+                @TestMetadata("UnannotatedWildcard.kt")
+                public void testUnannotatedWildcard() throws Exception {
+                    runTest("compiler/testData/diagnostics/foreignAnnotationsTests/java8Tests/jspecify/strictMode/UnannotatedWildcard.kt");
+                }
+
                 @Test
                 @TestMetadata("WildcardsWithDefault.kt")
                 public void testWildcardsWithDefault() throws Exception {
@@ -796,6 +802,12 @@ public class FirOldFrontendForeignAnnotationsCompiledJavaWithPsiClassReadingTest
                     runTest("compiler/testData/diagnostics/foreignAnnotationsTests/java8Tests/jspecify/warnMode/TypeParameterBounds.kt");
                 }
 
+                @Test
+                @TestMetadata("UnannotatedWildcard.kt")
+                public void testUnannotatedWildcard() throws Exception {
+                    runTest("compiler/testData/diagnostics/foreignAnnotationsTests/java8Tests/jspecify/warnMode/UnannotatedWildcard.kt");
+                }
+
                 @Test
                 @TestMetadata("WildcardsWithDefault.kt")
                 public void testWildcardsWithDefault() throws Exception {

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

@@ -714,6 +714,12 @@ public class FirOldFrontendForeignAnnotationsSourceJavaTestGenerated extends Abs
                     runTest("compiler/testData/diagnostics/foreignAnnotationsTests/java8Tests/jspecify/strictMode/TypeParameterBounds.kt");
                 }
 
+                @Test
+                @TestMetadata("UnannotatedWildcard.kt")
+                public void testUnannotatedWildcard() throws Exception {
+                    runTest("compiler/testData/diagnostics/foreignAnnotationsTests/java8Tests/jspecify/strictMode/UnannotatedWildcard.kt");
+                }
+
                 @Test
                 @TestMetadata("WildcardsWithDefault.kt")
                 public void testWildcardsWithDefault() throws Exception {
@@ -796,6 +802,12 @@ public class FirOldFrontendForeignAnnotationsSourceJavaTestGenerated extends Abs
                     runTest("compiler/testData/diagnostics/foreignAnnotationsTests/java8Tests/jspecify/warnMode/TypeParameterBounds.kt");
                 }
 
+                @Test
+                @TestMetadata("UnannotatedWildcard.kt")
+                public void testUnannotatedWildcard() throws Exception {
+                    runTest("compiler/testData/diagnostics/foreignAnnotationsTests/java8Tests/jspecify/warnMode/UnannotatedWildcard.kt");
+                }
+
                 @Test
                 @TestMetadata("WildcardsWithDefault.kt")
                 public void testWildcardsWithDefault() throws Exception {

compiler/testData/diagnostics/foreignAnnotationsTests/java8Tests/jspecify/strictMode/UnannotatedWildcard.fir.kt

@@ -0,0 +1,18 @@
+// JSPECIFY_STATE: strict
+// !LANGUAGE: +TypeEnhancementImprovementsInStrictMode
+
+// FILE: J1.java
+import org.jspecify.nullness.*;
+
+@NullMarked
+public interface J1<T extends @Nullable Object> {
+    T foo();
+}
+
+// FILE: J2.java
+public interface J2 {
+    J1<?> bar();
+}
+
+// FILE: main.kt
+fun baz(j2: J2): Any = <!RETURN_TYPE_MISMATCH, TYPE_MISMATCH!>j2.bar().foo()<!> // Any..Any?

compiler/testData/diagnostics/foreignAnnotationsTests/java8Tests/jspecify/strictMode/UnannotatedWildcard.kt

@@ -0,0 +1,18 @@
+// JSPECIFY_STATE: strict
+// !LANGUAGE: +TypeEnhancementImprovementsInStrictMode
+
+// FILE: J1.java
+import org.jspecify.nullness.*;
+
+@NullMarked
+public interface J1<T extends @Nullable Object> {
+    T foo();
+}
+
+// FILE: J2.java
+public interface J2 {
+    J1<?> bar();
+}
+
+// FILE: main.kt
+fun baz(j2: J2): Any = j2.bar().foo() // Any..Any?

compiler/testData/diagnostics/foreignAnnotationsTests/java8Tests/jspecify/strictMode/UnannotatedWildcard.txt

@@ -0,0 +1,17 @@
+package
+
+public fun baz(/*0*/ j2: J2): kotlin.Any
+
+@org.jspecify.nullness.NullMarked public interface J1</*0*/ T> {
+    public open override /*1*/ /*fake_override*/ fun equals(/*0*/ other: kotlin.Any?): kotlin.Boolean
+    public abstract fun foo(): T
+    public open override /*1*/ /*fake_override*/ fun hashCode(): kotlin.Int
+    public open override /*1*/ /*fake_override*/ fun toString(): kotlin.String
+}
+
+public interface J2 {
+    public abstract fun bar(): J1<out @org.jspecify.nullness.Nullable kotlin.Any!>!
+    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/foreignAnnotationsTests/java8Tests/jspecify/warnMode/UnannotatedWildcard.kt

@@ -0,0 +1,17 @@
+// FIR_IDENTICAL
+// JSPECIFY_STATE: warn
+// FILE: J1.java
+import org.jspecify.nullness.*;
+
+@NullMarked
+public interface J1<T extends @Nullable Object> {
+    T foo();
+}
+
+// FILE: J2.java
+public interface J2 {
+    J1<?> bar();
+}
+
+// FILE: main.kt
+fun baz(j2: J2): Any = j2.bar().foo() // Any..Any?

compiler/testData/diagnostics/foreignAnnotationsTests/java8Tests/jspecify/warnMode/UnannotatedWildcard.txt

@@ -0,0 +1,17 @@
+package
+
+public fun baz(/*0*/ j2: J2): kotlin.Any
+
+@org.jspecify.nullness.NullMarked public interface J1</*0*/ T : @org.jspecify.nullness.Nullable kotlin.Any!> {
+    public open override /*1*/ /*fake_override*/ fun equals(/*0*/ other: kotlin.Any?): kotlin.Boolean
+    public abstract fun foo(): T!
+    public open override /*1*/ /*fake_override*/ fun hashCode(): kotlin.Int
+    public open override /*1*/ /*fake_override*/ fun toString(): kotlin.String
+}
+
+public interface J2 {
+    public abstract fun bar(): J1<out @org.jspecify.nullness.Nullable kotlin.Any!>!
+    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/tests-common-new/tests-gen/org/jetbrains/kotlin/test/runners/ForeignAnnotationsCompiledJavaTestGenerated.java

@@ -714,6 +714,12 @@ public class ForeignAnnotationsCompiledJavaTestGenerated extends AbstractForeign
                     runTest("compiler/testData/diagnostics/foreignAnnotationsTests/java8Tests/jspecify/strictMode/TypeParameterBounds.kt");
                 }
 
+                @Test
+                @TestMetadata("UnannotatedWildcard.kt")
+                public void testUnannotatedWildcard() throws Exception {
+                    runTest("compiler/testData/diagnostics/foreignAnnotationsTests/java8Tests/jspecify/strictMode/UnannotatedWildcard.kt");
+                }
+
                 @Test
                 @TestMetadata("WildcardsWithDefault.kt")
                 public void testWildcardsWithDefault() throws Exception {
@@ -796,6 +802,12 @@ public class ForeignAnnotationsCompiledJavaTestGenerated extends AbstractForeign
                     runTest("compiler/testData/diagnostics/foreignAnnotationsTests/java8Tests/jspecify/warnMode/TypeParameterBounds.kt");
                 }
 
+                @Test
+                @TestMetadata("UnannotatedWildcard.kt")
+                public void testUnannotatedWildcard() throws Exception {
+                    runTest("compiler/testData/diagnostics/foreignAnnotationsTests/java8Tests/jspecify/warnMode/UnannotatedWildcard.kt");
+                }
+
                 @Test
                 @TestMetadata("WildcardsWithDefault.kt")
                 public void testWildcardsWithDefault() throws Exception {

compiler/tests-common-new/tests-gen/org/jetbrains/kotlin/test/runners/ForeignAnnotationsCompiledJavaWithPsiClassReadingTestGenerated.java

@@ -714,6 +714,12 @@ public class ForeignAnnotationsCompiledJavaWithPsiClassReadingTestGenerated exte
                     runTest("compiler/testData/diagnostics/foreignAnnotationsTests/java8Tests/jspecify/strictMode/TypeParameterBounds.kt");
                 }
 
+                @Test
+                @TestMetadata("UnannotatedWildcard.kt")
+                public void testUnannotatedWildcard() throws Exception {
+                    runTest("compiler/testData/diagnostics/foreignAnnotationsTests/java8Tests/jspecify/strictMode/UnannotatedWildcard.kt");
+                }
+
                 @Test
                 @TestMetadata("WildcardsWithDefault.kt")
                 public void testWildcardsWithDefault() throws Exception {
@@ -796,6 +802,12 @@ public class ForeignAnnotationsCompiledJavaWithPsiClassReadingTestGenerated exte
                     runTest("compiler/testData/diagnostics/foreignAnnotationsTests/java8Tests/jspecify/warnMode/TypeParameterBounds.kt");
                 }
 
+                @Test
+                @TestMetadata("UnannotatedWildcard.kt")
+                public void testUnannotatedWildcard() throws Exception {
+                    runTest("compiler/testData/diagnostics/foreignAnnotationsTests/java8Tests/jspecify/warnMode/UnannotatedWildcard.kt");
+                }
+
                 @Test
                 @TestMetadata("WildcardsWithDefault.kt")
                 public void testWildcardsWithDefault() throws Exception {

compiler/tests-common-new/tests-gen/org/jetbrains/kotlin/test/runners/ForeignAnnotationsSourceJavaTestGenerated.java

@@ -714,6 +714,12 @@ public class ForeignAnnotationsSourceJavaTestGenerated extends AbstractForeignAn
                     runTest("compiler/testData/diagnostics/foreignAnnotationsTests/java8Tests/jspecify/strictMode/TypeParameterBounds.kt");
                 }
 
+                @Test
+                @TestMetadata("UnannotatedWildcard.kt")
+                public void testUnannotatedWildcard() throws Exception {
+                    runTest("compiler/testData/diagnostics/foreignAnnotationsTests/java8Tests/jspecify/strictMode/UnannotatedWildcard.kt");
+                }
+
                 @Test
                 @TestMetadata("WildcardsWithDefault.kt")
                 public void testWildcardsWithDefault() throws Exception {
@@ -796,6 +802,12 @@ public class ForeignAnnotationsSourceJavaTestGenerated extends AbstractForeignAn
                     runTest("compiler/testData/diagnostics/foreignAnnotationsTests/java8Tests/jspecify/warnMode/TypeParameterBounds.kt");
                 }
 
+                @Test
+                @TestMetadata("UnannotatedWildcard.kt")
+                public void testUnannotatedWildcard() throws Exception {
+                    runTest("compiler/testData/diagnostics/foreignAnnotationsTests/java8Tests/jspecify/warnMode/UnannotatedWildcard.kt");
+                }
+
                 @Test
                 @TestMetadata("WildcardsWithDefault.kt")
                 public void testWildcardsWithDefault() throws Exception {

core/descriptors.jvm/src/org/jetbrains/kotlin/load/java/typeEnhancement/typeEnhancement.kt

@@ -119,6 +119,16 @@ class JavaTypeEnhancement(private val javaResolverSettings: JavaResolverSettings
             val enhanced = when {
                 !shouldEnhanceArguments -> Result(null, 0)
                 !arg.isStarProjection -> arg.type.unwrap().enhancePossiblyFlexible(qualifiers, globalArgIndex, isSuperTypesEnhancement)
+                qualifiers(globalArgIndex).nullability == FORCE_FLEXIBILITY ->
+                    arg.type.unwrap().let {
+                        // Given `C<T extends @Nullable V>`, unannotated `C<?>` is `C<out (V..V?)>`.
+                        Result(
+                            KotlinTypeFactory.flexibleType(
+                                it.lowerIfFlexible().makeNullableAsSpecified(false),
+                                it.upperIfFlexible().makeNullableAsSpecified(true)
+                            ), 1
+                        )
+                    }
                 else -> Result(null, 1)
             }
             globalArgIndex += enhanced.subtreeSize