[FIR] Syntax checkers

Introduce base class for checkers that dive into source trees.

compiler/fir/entrypoint/src/org/jetbrains/kotlin/fir/checkers/CommonDeclarationCheckers.kt

@@ -11,6 +11,9 @@ import org.jetbrains.kotlin.fir.analysis.cfa.FirPropertyInitializationAnalyzer
 import org.jetbrains.kotlin.fir.analysis.cfa.FirReturnsImpliesAnalyzer
 import org.jetbrains.kotlin.fir.analysis.checkers.cfa.FirControlFlowChecker
 import org.jetbrains.kotlin.fir.analysis.checkers.declaration.*
+import org.jetbrains.kotlin.fir.analysis.checkers.syntax.FirDelegationInInterfaceSyntaxChecker
+import org.jetbrains.kotlin.fir.analysis.checkers.syntax.FirFunctionTypeParametersSyntaxChecker
+import org.jetbrains.kotlin.fir.analysis.checkers.syntax.FirTypeParameterSyntaxChecker
 import org.jetbrains.kotlin.fir.analysis.checkers.expression.FirReservedUnderscoreDeclarationChecker
 
 object CommonDeclarationCheckers : DeclarationCheckers() {
@@ -43,7 +46,7 @@ object CommonDeclarationCheckers : DeclarationCheckers() {
     override val simpleFunctionCheckers: Set<FirSimpleFunctionChecker>
         get() = setOf(
             FirFunctionNameChecker,
-            FirFunctionTypeParametersChecker,
+            FirFunctionTypeParametersSyntaxChecker,
         )
 
     override val propertyCheckers: Set<FirPropertyChecker>
@@ -72,7 +75,7 @@ object CommonDeclarationCheckers : DeclarationCheckers() {
             FirCommonConstructorDelegationIssuesChecker,
             FirConstructorInInterfaceChecker,
             FirDelegationSuperCallInEnumConstructorChecker,
-            FirDelegationInInterfaceChecker,
+            FirDelegationInInterfaceSyntaxChecker,
             FirEnumClassSimpleChecker,
             FirInterfaceWithSuperclassChecker,
             FirLocalEntityNotAllowedChecker,
@@ -82,11 +85,11 @@ object CommonDeclarationCheckers : DeclarationCheckers() {
             FirPrimaryConstructorSuperTypeChecker,
             FirTypeParametersInObjectChecker,
             FirFunInterfaceDeclarationChecker,
-        FirMemberFunctionsChecker,
-        FirMemberPropertiesChecker,
-        FirNestedClassChecker,
-        FirInlineClassDeclarationChecker,
-    )
+            FirMemberFunctionsChecker,
+            FirMemberPropertiesChecker,
+            FirNestedClassChecker,
+            FirInlineClassDeclarationChecker,
+        )
 
     override val constructorCheckers: Set<FirConstructorChecker>
         get() = setOf(
@@ -116,5 +119,6 @@ object CommonDeclarationCheckers : DeclarationCheckers() {
             FirTypeParameterBoundsChecker,
             FirTypeParameterVarianceChecker,
             FirReifiedTypeParameterChecker,
+            FirTypeParameterSyntaxChecker,
         )
 }

compiler/fir/entrypoint/src/org/jetbrains/kotlin/fir/checkers/CommonExpressionCheckers.kt

@@ -6,6 +6,7 @@
 package org.jetbrains.kotlin.fir.checkers
 
 import org.jetbrains.kotlin.fir.analysis.checkers.expression.*
+import org.jetbrains.kotlin.fir.analysis.checkers.syntax.FirAnonymousFunctionSyntaxChecker
 
 object CommonExpressionCheckers : ExpressionCheckers() {
     override val annotationCallCheckers: Set<FirAnnotationCallChecker>
@@ -92,6 +93,7 @@ object CommonExpressionCheckers : ExpressionCheckers() {
     override val anonymousFunctionAsExpressionCheckers: Set<FirAnonymousFunctionAsExpressionChecker>
         get() = setOf(
             FirAnonymousFunctionChecker,
+            FirAnonymousFunctionSyntaxChecker,
         )
 
     override val typeOperatorCallCheckers: Set<FirTypeOperatorCallChecker>

compiler/fir/entrypoint/src/org/jetbrains/kotlin/fir/checkers/ExtendedDeclarationCheckers.kt

@@ -9,17 +9,16 @@ import org.jetbrains.kotlin.fir.analysis.cfa.AbstractFirPropertyInitializationCh
 import org.jetbrains.kotlin.fir.analysis.checkers.cfa.FirControlFlowChecker
 import org.jetbrains.kotlin.fir.analysis.checkers.declaration.*
 import org.jetbrains.kotlin.fir.analysis.checkers.extended.*
-import org.jetbrains.kotlin.fir.declarations.FirDeclaration
 
 object ExtendedDeclarationCheckers : DeclarationCheckers() {
     override val basicDeclarationCheckers: Set<FirBasicDeclarationChecker>
         get() = setOf(
-            RedundantVisibilityModifierChecker,
+            RedundantVisibilityModifierSyntaxChecker,
         )
 
     override val memberDeclarationCheckers: Set<FirMemberDeclarationChecker>
         get() = setOf(
-            RedundantModalityModifierChecker,
+            RedundantModalityModifierSyntaxChecker,
             RedundantExplicitTypeChecker,
             RedundantSetterParameterTypeChecker,
         )