[FIR] Report warnings for inconsistent visibilities of accessors

K1 didn't report diagnostics for accessors
of intersection overrides, so this change
prevents a BC.

^KT-66046 Fixed

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

@@ -2718,6 +2718,15 @@ internal val KT_DIAGNOSTIC_CONVERTER = KtDiagnosticConverterBuilder.buildConvert
             token,
         )
     }
+    add(FirErrors.CANNOT_WEAKEN_ACCESS_PRIVILEGE_WARNING) { firDiagnostic ->
+        CannotWeakenAccessPrivilegeWarningImpl(
+            firDiagnostic.a,
+            firSymbolBuilder.callableBuilder.buildCallableSymbol(firDiagnostic.b),
+            firDiagnostic.c,
+            firDiagnostic as KtPsiDiagnostic,
+            token,
+        )
+    }
     add(FirErrors.CANNOT_CHANGE_ACCESS_PRIVILEGE) { firDiagnostic ->
         CannotChangeAccessPrivilegeImpl(
             firDiagnostic.a,
@@ -2727,6 +2736,15 @@ internal val KT_DIAGNOSTIC_CONVERTER = KtDiagnosticConverterBuilder.buildConvert
             token,
         )
     }
+    add(FirErrors.CANNOT_CHANGE_ACCESS_PRIVILEGE_WARNING) { firDiagnostic ->
+        CannotChangeAccessPrivilegeWarningImpl(
+            firDiagnostic.a,
+            firSymbolBuilder.callableBuilder.buildCallableSymbol(firDiagnostic.b),
+            firDiagnostic.c,
+            firDiagnostic as KtPsiDiagnostic,
+            token,
+        )
+    }
     add(FirErrors.CANNOT_INFER_VISIBILITY) { firDiagnostic ->
         CannotInferVisibilityImpl(
             firSymbolBuilder.callableBuilder.buildCallableSymbol(firDiagnostic.a),
@@ -2734,6 +2752,13 @@ internal val KT_DIAGNOSTIC_CONVERTER = KtDiagnosticConverterBuilder.buildConvert
             token,
         )
     }
+    add(FirErrors.CANNOT_INFER_VISIBILITY_WARNING) { firDiagnostic ->
+        CannotInferVisibilityWarningImpl(
+            firSymbolBuilder.callableBuilder.buildCallableSymbol(firDiagnostic.a),
+            firDiagnostic as KtPsiDiagnostic,
+            token,
+        )
+    }
     add(FirErrors.MULTIPLE_DEFAULTS_INHERITED_FROM_SUPERTYPES) { firDiagnostic ->
         MultipleDefaultsInheritedFromSupertypesImpl(
             firDiagnostic.a,

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

@@ -1925,6 +1925,13 @@ sealed interface KtFirDiagnostic<PSI : PsiElement> : KtDiagnosticWithPsi<PSI> {
         val containingClassName: Name
     }
 
+    interface CannotWeakenAccessPrivilegeWarning : KtFirDiagnostic<KtModifierListOwner> {
+        override val diagnosticClass get() = CannotWeakenAccessPrivilegeWarning::class
+        val overridingVisibility: Visibility
+        val overridden: KtCallableSymbol
+        val containingClassName: Name
+    }
+
     interface CannotChangeAccessPrivilege : KtFirDiagnostic<KtModifierListOwner> {
         override val diagnosticClass get() = CannotChangeAccessPrivilege::class
         val overridingVisibility: Visibility
@@ -1932,11 +1939,23 @@ sealed interface KtFirDiagnostic<PSI : PsiElement> : KtDiagnosticWithPsi<PSI> {
         val containingClassName: Name
     }
 
+    interface CannotChangeAccessPrivilegeWarning : KtFirDiagnostic<KtModifierListOwner> {
+        override val diagnosticClass get() = CannotChangeAccessPrivilegeWarning::class
+        val overridingVisibility: Visibility
+        val overridden: KtCallableSymbol
+        val containingClassName: Name
+    }
+
     interface CannotInferVisibility : KtFirDiagnostic<KtDeclaration> {
         override val diagnosticClass get() = CannotInferVisibility::class
         val callable: KtCallableSymbol
     }
 
+    interface CannotInferVisibilityWarning : KtFirDiagnostic<KtDeclaration> {
+        override val diagnosticClass get() = CannotInferVisibilityWarning::class
+        val callable: KtCallableSymbol
+    }
+
     interface MultipleDefaultsInheritedFromSupertypes : KtFirDiagnostic<KtElement> {
         override val diagnosticClass get() = MultipleDefaultsInheritedFromSupertypes::class
         val name: Name

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

@@ -2313,6 +2313,14 @@ internal class CannotWeakenAccessPrivilegeImpl(
     token: KtLifetimeToken,
 ) : KtAbstractFirDiagnostic<KtModifierListOwner>(firDiagnostic, token), KtFirDiagnostic.CannotWeakenAccessPrivilege
 
+internal class CannotWeakenAccessPrivilegeWarningImpl(
+    override val overridingVisibility: Visibility,
+    override val overridden: KtCallableSymbol,
+    override val containingClassName: Name,
+    firDiagnostic: KtPsiDiagnostic,
+    token: KtLifetimeToken,
+) : KtAbstractFirDiagnostic<KtModifierListOwner>(firDiagnostic, token), KtFirDiagnostic.CannotWeakenAccessPrivilegeWarning
+
 internal class CannotChangeAccessPrivilegeImpl(
     override val overridingVisibility: Visibility,
     override val overridden: KtCallableSymbol,
@@ -2321,12 +2329,26 @@ internal class CannotChangeAccessPrivilegeImpl(
     token: KtLifetimeToken,
 ) : KtAbstractFirDiagnostic<KtModifierListOwner>(firDiagnostic, token), KtFirDiagnostic.CannotChangeAccessPrivilege
 
+internal class CannotChangeAccessPrivilegeWarningImpl(
+    override val overridingVisibility: Visibility,
+    override val overridden: KtCallableSymbol,
+    override val containingClassName: Name,
+    firDiagnostic: KtPsiDiagnostic,
+    token: KtLifetimeToken,
+) : KtAbstractFirDiagnostic<KtModifierListOwner>(firDiagnostic, token), KtFirDiagnostic.CannotChangeAccessPrivilegeWarning
+
 internal class CannotInferVisibilityImpl(
     override val callable: KtCallableSymbol,
     firDiagnostic: KtPsiDiagnostic,
     token: KtLifetimeToken,
 ) : KtAbstractFirDiagnostic<KtDeclaration>(firDiagnostic, token), KtFirDiagnostic.CannotInferVisibility
 
+internal class CannotInferVisibilityWarningImpl(
+    override val callable: KtCallableSymbol,
+    firDiagnostic: KtPsiDiagnostic,
+    token: KtLifetimeToken,
+) : KtAbstractFirDiagnostic<KtDeclaration>(firDiagnostic, token), KtFirDiagnostic.CannotInferVisibilityWarning
+
 internal class MultipleDefaultsInheritedFromSupertypesImpl(
     override val name: Name,
     override val valueParameter: KtSymbol,

analysis/low-level-api-fir/tests/org/jetbrains/kotlin/analysis/low/level/api/fir/diagnostic/compiler/based/DiagnosticCompilerTestFE10TestdataTestGenerated.java

@@ -657,6 +657,12 @@ public class DiagnosticCompilerTestFE10TestdataTestGenerated extends AbstractDia
       runTest("compiler/testData/diagnostics/tests/intersectedVisibilitiesForNonAbstractPropertyAccessors.kt");
     }
 
+    @Test
+    @TestMetadata("intersectedVisibilitiesPropertyAccessorsAdditionalWarnigns.kt")
+    public void testIntersectedVisibilitiesPropertyAccessorsAdditionalWarnigns() {
+      runTest("compiler/testData/diagnostics/tests/intersectedVisibilitiesPropertyAccessorsAdditionalWarnigns.kt");
+    }
+
     @Test
     @TestMetadata("intersectionWithMultipleDefaultsInJava.kt")
     public void testIntersectionWithMultipleDefaultsInJava() {

analysis/low-level-api-fir/tests/org/jetbrains/kotlin/analysis/low/level/api/fir/diagnostic/compiler/based/LLFirPreresolvedReversedDiagnosticCompilerFE10TestDataTestGenerated.java

@@ -657,6 +657,12 @@ public class LLFirPreresolvedReversedDiagnosticCompilerFE10TestDataTestGenerated
       runTest("compiler/testData/diagnostics/tests/intersectedVisibilitiesForNonAbstractPropertyAccessors.kt");
     }
 
+    @Test
+    @TestMetadata("intersectedVisibilitiesPropertyAccessorsAdditionalWarnigns.kt")
+    public void testIntersectedVisibilitiesPropertyAccessorsAdditionalWarnigns() {
+      runTest("compiler/testData/diagnostics/tests/intersectedVisibilitiesPropertyAccessorsAdditionalWarnigns.kt");
+    }
+
     @Test
     @TestMetadata("intersectionWithMultipleDefaultsInJava.kt")
     public void testIntersectionWithMultipleDefaultsInJava() {