[FIR] Introduce & use VISIBILITY_MODIFIER positioning strategy

compiler/fir/checkers/src/org/jetbrains/kotlin/fir/analysis/checkers/extended/RedundantVisibilityModifierChecker.kt

@@ -16,7 +16,6 @@ import org.jetbrains.kotlin.fir.analysis.checkers.context.CheckerContext
 import org.jetbrains.kotlin.fir.analysis.checkers.declaration.FirBasicDeclarationChecker
 import org.jetbrains.kotlin.fir.analysis.diagnostics.DiagnosticReporter
 import org.jetbrains.kotlin.fir.analysis.diagnostics.FirErrors
-import org.jetbrains.kotlin.fir.analysis.getChild
 import org.jetbrains.kotlin.fir.declarations.*
 import org.jetbrains.kotlin.lexer.KtModifierKeywordToken
 import org.jetbrains.kotlin.lexer.KtTokens
@@ -56,7 +55,7 @@ object RedundantVisibilityModifierChecker : FirBasicDeclarationChecker() {
             && declaration.setter?.visibility == Visibilities.Public
         ) return
 
-        reporter.report(declaration.source?.getChild(KtTokens.VISIBILITY_MODIFIERS), FirErrors.REDUNDANT_VISIBILITY_MODIFIER)
+        reporter.report(declaration.source, FirErrors.REDUNDANT_VISIBILITY_MODIFIER)
     }
 
     private fun FirDeclaration.implicitVisibility(context: CheckerContext): Visibility {

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

@@ -154,7 +154,7 @@ object FirErrors {
     val WRONG_IMPLIES_CONDITION by error0<FirSourceElement, PsiElement>()
 
     // Extended checkers group
-    val REDUNDANT_VISIBILITY_MODIFIER by warning0<FirSourceElement, PsiElement>()
+    val REDUNDANT_VISIBILITY_MODIFIER by warning0<FirSourceElement, KtModifierListOwner>(SourceElementPositioningStrategies.VISIBILITY_MODIFIER)
     val REDUNDANT_MODALITY_MODIFIER by warning0<FirSourceElement, PsiElement>()
     val REDUNDANT_RETURN_UNIT_TYPE by warning0<FirSourceElement, PsiTypeElement>()
     val REDUNDANT_EXPLICIT_TYPE by warning0<FirSourceElement, PsiElement>()

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

@@ -143,6 +143,22 @@ object LightTreePositioningStrategies {
         }
     }
 
+    val VISIBILITY_MODIFIER: LightTreePositioningStrategy = object : LightTreePositioningStrategy() {
+        override fun mark(node: LighterASTNode, tree: FlyweightCapableTreeStructure<LighterASTNode>): List<TextRange> {
+            tree.visibilityModifier(node)?.let { return markElement(it, tree) }
+            tree.nameIdentifier(node)?.let { return markElement(it, tree) }
+            return when (node.tokenType) {
+                KtNodeTypes.OBJECT_DECLARATION -> {
+                    markElement(tree.objectKeyword(node)!!, tree)
+                }
+                KtNodeTypes.PROPERTY_ACCESSOR -> {
+                    markElement(tree.accessorNamePlaceholder(node), tree)
+                }
+                else -> markElement(node, tree)
+            }
+        }
+    }
+
     val OPERATOR: LightTreePositioningStrategy = object : LightTreePositioningStrategy() {
         override fun mark(node: LighterASTNode, tree: FlyweightCapableTreeStructure<LighterASTNode>): List<TextRange> {
             return markElement(tree.operationReference(node) ?: node, tree)
@@ -180,6 +196,9 @@ private fun FlyweightCapableTreeStructure<LighterASTNode>.objectKeyword(node: Li
 private fun FlyweightCapableTreeStructure<LighterASTNode>.valOrVarKeyword(node: LighterASTNode): LighterASTNode? =
     findChildByType(node, VAL_VAR_TOKEN_SET)
 
+private fun FlyweightCapableTreeStructure<LighterASTNode>.visibilityModifier(node: LighterASTNode): LighterASTNode? =
+    findChildByType(node, KtTokens.VISIBILITY_MODIFIERS)
+
 private fun FlyweightCapableTreeStructure<LighterASTNode>.accessorNamePlaceholder(node: LighterASTNode): LighterASTNode =
     findChildByType(node, KtTokens.GET_KEYWORD) ?: findChildByType(node, KtTokens.SET_KEYWORD)!!
 

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

@@ -33,6 +33,11 @@ object SourceElementPositioningStrategies {
         PositioningStrategies.DECLARATION_SIGNATURE
     )
 
+    val VISIBILITY_MODIFIER = SourceElementPositioningStrategy(
+        LightTreePositioningStrategies.VISIBILITY_MODIFIER,
+        PositioningStrategies.VISIBILITY_MODIFIER
+    )
+
     val OPERATOR = SourceElementPositioningStrategy(
         LightTreePositioningStrategies.OPERATOR,
         PositioningStrategies.OPERATOR

compiler/frontend/src/org/jetbrains/kotlin/diagnostics/PositioningStrategies.kt

@@ -17,6 +17,7 @@ import org.jetbrains.kotlin.diagnostics.Errors.ACTUAL_WITHOUT_EXPECT
 import org.jetbrains.kotlin.diagnostics.Errors.NO_ACTUAL_FOR_EXPECT
 import org.jetbrains.kotlin.lexer.KtModifierKeywordToken
 import org.jetbrains.kotlin.lexer.KtTokens
+import org.jetbrains.kotlin.lexer.KtTokens.VISIBILITY_MODIFIERS
 import org.jetbrains.kotlin.psi.*
 import org.jetbrains.kotlin.psi.psiUtil.*
 import org.jetbrains.kotlin.resolve.multiplatform.ExpectedActualResolver.Compatibility.Incompatible
@@ -405,12 +406,10 @@ object PositioningStrategies {
     @JvmField
     val VISIBILITY_MODIFIER: PositioningStrategy<KtModifierListOwner> = object : PositioningStrategy<KtModifierListOwner>() {
         override fun mark(element: KtModifierListOwner): List<TextRange> {
-            val visibilityTokens =
-                listOf(KtTokens.PRIVATE_KEYWORD, KtTokens.PROTECTED_KEYWORD, KtTokens.PUBLIC_KEYWORD, KtTokens.INTERNAL_KEYWORD)
             val modifierList = element.modifierList
 
-            val result = visibilityTokens.mapNotNull { modifierList?.getModifier(it)?.textRange }
+            val result = VISIBILITY_MODIFIERS.types.mapNotNull { modifierList?.getModifier(it as KtModifierKeywordToken)?.textRange }
-            if (!result.isEmpty()) return result
+            if (result.isNotEmpty()) return result
 
             // Try to resolve situation when there's no visibility modifiers written before element
             if (element is PsiNameIdentifierOwner) {