[FIR] Refactoring extended checkers

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

@@ -6,10 +6,10 @@
 package org.jetbrains.kotlin.fir.analysis.checkers.extended
 
 import org.jetbrains.kotlin.fir.analysis.checkers.context.CheckerContext
-import org.jetbrains.kotlin.fir.analysis.checkers.eqOperatorSource
 import org.jetbrains.kotlin.fir.analysis.checkers.expression.FirBasicExpresionChecker
 import org.jetbrains.kotlin.fir.analysis.diagnostics.DiagnosticReporter
 import org.jetbrains.kotlin.fir.analysis.diagnostics.FirErrors.ARRAY_EQUALITY_OPERATOR_CAN_BE_REPLACED_WITH_EQUALS
+import org.jetbrains.kotlin.fir.analysis.getChildren
 import org.jetbrains.kotlin.fir.expressions.FirEqualityOperatorCall
 import org.jetbrains.kotlin.fir.expressions.FirOperation
 import org.jetbrains.kotlin.fir.expressions.FirStatement
@@ -17,6 +17,7 @@ import org.jetbrains.kotlin.fir.expressions.arguments
 import org.jetbrains.kotlin.fir.symbols.StandardClassIds
 import org.jetbrains.kotlin.fir.types.classId
 import org.jetbrains.kotlin.fir.types.coneType
+import org.jetbrains.kotlin.lexer.KtTokens
 
 object ArrayEqualityCanBeReplacedWithEquals : FirBasicExpresionChecker() {
     override fun check(expression: FirStatement, context: CheckerContext, reporter: DiagnosticReporter) {
@@ -28,6 +29,7 @@ object ArrayEqualityCanBeReplacedWithEquals : FirBasicExpresionChecker() {
         if (left.typeRef.coneType.classId != StandardClassIds.Array) return
         if (right.typeRef.coneType.classId != StandardClassIds.Array) return
 
-        reporter.report(expression.source?.eqOperatorSource(), ARRAY_EQUALITY_OPERATOR_CAN_BE_REPLACED_WITH_EQUALS)
+        val source = expression.source?.getChildren(setOf(KtTokens.EQEQ, KtTokens.EXCLEQ))
+        reporter.report(source, ARRAY_EQUALITY_OPERATOR_CAN_BE_REPLACED_WITH_EQUALS)
     }
 }

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

@@ -13,10 +13,10 @@ import org.jetbrains.kotlin.fir.FirFakeSourceElementKind
 import org.jetbrains.kotlin.fir.FirLightSourceElement
 import org.jetbrains.kotlin.fir.FirPsiSourceElement
 import org.jetbrains.kotlin.fir.analysis.checkers.context.CheckerContext
-import org.jetbrains.kotlin.fir.analysis.checkers.eqOperatorSource
 import org.jetbrains.kotlin.fir.analysis.checkers.expression.FirExpressionChecker
 import org.jetbrains.kotlin.fir.analysis.diagnostics.DiagnosticReporter
 import org.jetbrains.kotlin.fir.analysis.diagnostics.FirErrors
+import org.jetbrains.kotlin.fir.analysis.getChildren
 import org.jetbrains.kotlin.fir.expressions.FirFunctionCall
 import org.jetbrains.kotlin.fir.expressions.FirVariableAssignment
 import org.jetbrains.kotlin.fir.expressions.toResolvedCallableSymbol
@@ -62,8 +62,8 @@ object CanBeReplacedWithOperatorAssignmentChecker : FirExpressionChecker<FirVari
         }
 
         if (needToReport) {
-            val reportSource = expression.source?.eqOperatorSource()
-            reporter.report(reportSource, FirErrors.CAN_BE_REPLACED_WITH_OPERATOR_ASSIGNMENT)
+            val source = expression.source?.getChildren(setOf(KtTokens.EQ))
+            reporter.report(source, FirErrors.CAN_BE_REPLACED_WITH_OPERATOR_ASSIGNMENT)
         }
 
     }

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

@@ -12,11 +12,12 @@ import org.jetbrains.kotlin.fir.FirSourceElement
 import org.jetbrains.kotlin.fir.analysis.checkers.FirModifier
 import org.jetbrains.kotlin.fir.analysis.checkers.context.CheckerContext
 import org.jetbrains.kotlin.fir.analysis.checkers.declaration.FirMemberDeclarationChecker
-import org.jetbrains.kotlin.fir.analysis.checkers.getModifierList
 import org.jetbrains.kotlin.fir.analysis.checkers.implicitModality
 import org.jetbrains.kotlin.fir.analysis.checkers.source
+import org.jetbrains.kotlin.fir.analysis.checkers.toToken
 import org.jetbrains.kotlin.fir.analysis.diagnostics.DiagnosticReporter
 import org.jetbrains.kotlin.fir.analysis.diagnostics.FirErrors.REDUNDANT_MODALITY_MODIFIER
+import org.jetbrains.kotlin.fir.analysis.getChildren
 import org.jetbrains.kotlin.fir.declarations.FirClass
 import org.jetbrains.kotlin.fir.declarations.FirMemberDeclaration
 import org.jetbrains.kotlin.fir.declarations.modality
@@ -36,7 +37,7 @@ object RedundantModalityModifierChecker : FirMemberDeclarationChecker() {
 
         if (modality != implicitModality) return
 
-        val modalityModifierSource = declaration.source.getModifierList()?.modifiers?.modalitySource()
+        val modalityModifierSource = declaration.source?.getChildren(modality.toToken(), depth = 2)
         reporter.report(modalityModifierSource, REDUNDANT_MODALITY_MODIFIER)
     }
 

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

@@ -7,17 +7,19 @@ package org.jetbrains.kotlin.fir.analysis.checkers.extended
 
 import org.jetbrains.kotlin.descriptors.ClassKind
 import org.jetbrains.kotlin.descriptors.Modality
-import org.jetbrains.kotlin.fir.*
+import org.jetbrains.kotlin.fir.FirFakeSourceElement
+import org.jetbrains.kotlin.fir.FirFakeSourceElementKind
+import org.jetbrains.kotlin.fir.Visibilities
+import org.jetbrains.kotlin.fir.Visibility
 import org.jetbrains.kotlin.fir.analysis.checkers.*
 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.getChildren
 import org.jetbrains.kotlin.fir.declarations.*
 import org.jetbrains.kotlin.lexer.KtModifierKeywordToken
 import org.jetbrains.kotlin.lexer.KtTokens
-import org.jetbrains.kotlin.psi.KtModifierListOwner
-import org.jetbrains.kotlin.psi.psiUtil.visibilityModifier
 
 object RedundantVisibilityModifierChecker : FirBasicDeclarationChecker() {
     override fun check(declaration: FirDeclaration, context: CheckerContext, reporter: DiagnosticReporter) {
@@ -54,7 +56,7 @@ object RedundantVisibilityModifierChecker : FirBasicDeclarationChecker() {
             && declaration.setter?.visibility == Visibilities.Public
         ) return
 
-        reporter.report(declaration.source.modifierSource, FirErrors.REDUNDANT_VISIBILITY_MODIFIER)
+        reporter.report(declaration.source?.getChildren(KtTokens.VISIBILITY_MODIFIERS), FirErrors.REDUNDANT_VISIBILITY_MODIFIER)
     }
 
     private fun FirDeclaration.implicitVisibility(context: CheckerContext): Visibility {
@@ -71,7 +73,7 @@ object RedundantVisibilityModifierChecker : FirBasicDeclarationChecker() {
                     clazz is FirClass
                     && (clazz.classKind == ClassKind.ENUM_CLASS || clazz.modality() == Modality.SEALED)
                 ) {
-                    return Visibilities.Private
+                    Visibilities.Private
                 } else {
                     Visibilities.DEFAULT_VISIBILITY
                 }
@@ -125,15 +127,6 @@ object RedundantVisibilityModifierChecker : FirBasicDeclarationChecker() {
     private val CheckerContext.containingPropertyVisibility
         get() = (this.containingDeclarations.last() as? FirProperty)?.visibility
 
-    private val FirSourceElement?.modifierSource: FirSourceElement?
-        get() = when (this) {
-            null -> null
-            is FirPsiSourceElement<*> -> (psi as? KtModifierListOwner)?.modifierList?.visibilityModifier()?.toFirPsiSourceElement()
-            is FirLightSourceElement -> {
-                val modifier = this.getModifierList()?.modifiers?.firstOrNull { it.isVisibilityModifier }
-                modifier?.source
-            }
-        }
 
     private val FirModifier<*>.isVisibilityModifier
         get() = this.token.toVisibilityOrNull() != null