diff --git a/compiler/fir/checkers/src/org/jetbrains/kotlin/fir/analysis/checkers/declaration/FirModifierUtils.kt b/compiler/fir/checkers/src/org/jetbrains/kotlin/fir/analysis/checkers/FirModifierUtils.kt
similarity index 97%
rename from compiler/fir/checkers/src/org/jetbrains/kotlin/fir/analysis/checkers/declaration/FirModifierUtils.kt
rename to compiler/fir/checkers/src/org/jetbrains/kotlin/fir/analysis/checkers/FirModifierUtils.kt
index feb646d1012..c9fb26237cb 100644
--- a/compiler/fir/checkers/src/org/jetbrains/kotlin/fir/analysis/checkers/declaration/FirModifierUtils.kt
+++ b/compiler/fir/checkers/src/org/jetbrains/kotlin/fir/analysis/checkers/FirModifierUtils.kt
@@ -3,7 +3,7 @@
  * Use of this source code is governed by the Apache 2.0 license that can be found in the license/LICENSE.txt file.
  */
 
-package org.jetbrains.kotlin.fir.analysis.checkers.declaration
+package org.jetbrains.kotlin.fir.analysis.checkers
 
 import com.intellij.lang.ASTNode
 import com.intellij.lang.LighterASTNode
@@ -11,7 +11,6 @@ import com.intellij.psi.tree.TokenSet
 import com.intellij.util.diff.FlyweightCapableTreeStructure
 import org.jetbrains.kotlin.KtNodeTypes
 import org.jetbrains.kotlin.fir.*
-import org.jetbrains.kotlin.fir.analysis.checkers.getChildren
 import org.jetbrains.kotlin.lexer.KtModifierKeywordToken
 import org.jetbrains.kotlin.lexer.KtTokens
 import org.jetbrains.kotlin.psi.KtModifierList
diff --git a/compiler/fir/checkers/src/org/jetbrains/kotlin/fir/analysis/checkers/declaration/FirConstPropertyChecker.kt b/compiler/fir/checkers/src/org/jetbrains/kotlin/fir/analysis/checkers/declaration/FirConstPropertyChecker.kt
index d0766ef9ee4..08df9eb4d0a 100644
--- a/compiler/fir/checkers/src/org/jetbrains/kotlin/fir/analysis/checkers/declaration/FirConstPropertyChecker.kt
+++ b/compiler/fir/checkers/src/org/jetbrains/kotlin/fir/analysis/checkers/declaration/FirConstPropertyChecker.kt
@@ -10,6 +10,7 @@ import org.jetbrains.kotlin.fir.FirFakeSourceElementKind
 import org.jetbrains.kotlin.fir.analysis.checkers.canBeUsedForConstVal
 import org.jetbrains.kotlin.fir.analysis.checkers.checkConstantArguments
 import org.jetbrains.kotlin.fir.analysis.checkers.context.CheckerContext
+import org.jetbrains.kotlin.fir.analysis.checkers.getModifier
 import org.jetbrains.kotlin.fir.analysis.diagnostics.DiagnosticReporter
 import org.jetbrains.kotlin.fir.analysis.diagnostics.FirErrors
 import org.jetbrains.kotlin.fir.analysis.diagnostics.reportOn
diff --git a/compiler/fir/checkers/src/org/jetbrains/kotlin/fir/analysis/checkers/declaration/FirConstructorAllowedChecker.kt b/compiler/fir/checkers/src/org/jetbrains/kotlin/fir/analysis/checkers/declaration/FirConstructorAllowedChecker.kt
index dcac87d497f..f17fa5fd5b1 100644
--- a/compiler/fir/checkers/src/org/jetbrains/kotlin/fir/analysis/checkers/declaration/FirConstructorAllowedChecker.kt
+++ b/compiler/fir/checkers/src/org/jetbrains/kotlin/fir/analysis/checkers/declaration/FirConstructorAllowedChecker.kt
@@ -10,6 +10,7 @@ import org.jetbrains.kotlin.descriptors.ClassKind
 import org.jetbrains.kotlin.descriptors.Modality
 import org.jetbrains.kotlin.descriptors.Visibilities
 import org.jetbrains.kotlin.fir.analysis.checkers.context.CheckerContext
+import org.jetbrains.kotlin.fir.analysis.checkers.getModifierList
 import org.jetbrains.kotlin.fir.analysis.diagnostics.DiagnosticReporter
 import org.jetbrains.kotlin.fir.analysis.diagnostics.FirErrors
 import org.jetbrains.kotlin.fir.analysis.diagnostics.reportOn
diff --git a/compiler/fir/checkers/src/org/jetbrains/kotlin/fir/analysis/checkers/declaration/FirDeclarationCheckerUtils.kt b/compiler/fir/checkers/src/org/jetbrains/kotlin/fir/analysis/checkers/declaration/FirDeclarationCheckerUtils.kt
index 2dc73dfd609..7f0d40a77b0 100644
--- a/compiler/fir/checkers/src/org/jetbrains/kotlin/fir/analysis/checkers/declaration/FirDeclarationCheckerUtils.kt
+++ b/compiler/fir/checkers/src/org/jetbrains/kotlin/fir/analysis/checkers/declaration/FirDeclarationCheckerUtils.kt
@@ -9,7 +9,10 @@ import org.jetbrains.kotlin.descriptors.ClassKind
 import org.jetbrains.kotlin.descriptors.Modality
 import org.jetbrains.kotlin.descriptors.Visibilities
 import org.jetbrains.kotlin.fir.FirSourceElement
+import org.jetbrains.kotlin.fir.analysis.checkers.FirModifierList
+import org.jetbrains.kotlin.fir.analysis.checkers.contains
 import org.jetbrains.kotlin.fir.analysis.checkers.context.CheckerContext
+import org.jetbrains.kotlin.fir.analysis.checkers.hasModifier
 import org.jetbrains.kotlin.fir.analysis.checkers.modality
 import org.jetbrains.kotlin.fir.analysis.diagnostics.DiagnosticReporter
 import org.jetbrains.kotlin.fir.analysis.diagnostics.FirErrors
diff --git a/compiler/fir/checkers/src/org/jetbrains/kotlin/fir/analysis/checkers/declaration/FirInlineClassDeclarationChecker.kt b/compiler/fir/checkers/src/org/jetbrains/kotlin/fir/analysis/checkers/declaration/FirInlineClassDeclarationChecker.kt
index 15a4e00bc36..2fd46c900e3 100644
--- a/compiler/fir/checkers/src/org/jetbrains/kotlin/fir/analysis/checkers/declaration/FirInlineClassDeclarationChecker.kt
+++ b/compiler/fir/checkers/src/org/jetbrains/kotlin/fir/analysis/checkers/declaration/FirInlineClassDeclarationChecker.kt
@@ -8,6 +8,7 @@ package org.jetbrains.kotlin.fir.analysis.checkers.declaration
 import org.jetbrains.kotlin.descriptors.Modality
 import org.jetbrains.kotlin.fir.*
 import org.jetbrains.kotlin.fir.analysis.checkers.context.CheckerContext
+import org.jetbrains.kotlin.fir.analysis.checkers.hasModifier
 import org.jetbrains.kotlin.fir.analysis.checkers.toRegularClass
 import org.jetbrains.kotlin.fir.analysis.diagnostics.DiagnosticReporter
 import org.jetbrains.kotlin.fir.analysis.diagnostics.FirErrors
diff --git a/compiler/fir/checkers/src/org/jetbrains/kotlin/fir/analysis/checkers/declaration/FirMemberFunctionsChecker.kt b/compiler/fir/checkers/src/org/jetbrains/kotlin/fir/analysis/checkers/declaration/FirMemberFunctionsChecker.kt
index e603383bf44..701fe180fce 100644
--- a/compiler/fir/checkers/src/org/jetbrains/kotlin/fir/analysis/checkers/declaration/FirMemberFunctionsChecker.kt
+++ b/compiler/fir/checkers/src/org/jetbrains/kotlin/fir/analysis/checkers/declaration/FirMemberFunctionsChecker.kt
@@ -7,7 +7,9 @@ package org.jetbrains.kotlin.fir.analysis.checkers.declaration
 
 import org.jetbrains.kotlin.descriptors.Visibilities
 import org.jetbrains.kotlin.fir.FirFakeSourceElementKind
+import org.jetbrains.kotlin.fir.analysis.checkers.contains
 import org.jetbrains.kotlin.fir.analysis.checkers.context.CheckerContext
+import org.jetbrains.kotlin.fir.analysis.checkers.getModifierList
 import org.jetbrains.kotlin.fir.analysis.diagnostics.DiagnosticReporter
 import org.jetbrains.kotlin.fir.analysis.diagnostics.FirErrors
 import org.jetbrains.kotlin.fir.analysis.diagnostics.reportOn
diff --git a/compiler/fir/checkers/src/org/jetbrains/kotlin/fir/analysis/checkers/declaration/FirMemberPropertiesChecker.kt b/compiler/fir/checkers/src/org/jetbrains/kotlin/fir/analysis/checkers/declaration/FirMemberPropertiesChecker.kt
index 17bcf025af2..f7cc5d78d3b 100644
--- a/compiler/fir/checkers/src/org/jetbrains/kotlin/fir/analysis/checkers/declaration/FirMemberPropertiesChecker.kt
+++ b/compiler/fir/checkers/src/org/jetbrains/kotlin/fir/analysis/checkers/declaration/FirMemberPropertiesChecker.kt
@@ -12,7 +12,9 @@ import org.jetbrains.kotlin.fir.FirFakeSourceElementKind
 import org.jetbrains.kotlin.fir.FirSourceElement
 import org.jetbrains.kotlin.fir.analysis.cfa.PropertyInitializationInfo
 import org.jetbrains.kotlin.fir.analysis.cfa.PropertyInitializationInfoCollector
+import org.jetbrains.kotlin.fir.analysis.checkers.contains
 import org.jetbrains.kotlin.fir.analysis.checkers.context.CheckerContext
+import org.jetbrains.kotlin.fir.analysis.checkers.getModifierList
 import org.jetbrains.kotlin.fir.analysis.diagnostics.DiagnosticReporter
 import org.jetbrains.kotlin.fir.analysis.diagnostics.FirErrors
 import org.jetbrains.kotlin.fir.analysis.diagnostics.reportOn
diff --git a/compiler/fir/checkers/src/org/jetbrains/kotlin/fir/analysis/checkers/declaration/FirModifierChecker.kt b/compiler/fir/checkers/src/org/jetbrains/kotlin/fir/analysis/checkers/declaration/FirModifierChecker.kt
index 1a3f0e4c1c8..d164dad6716 100644
--- a/compiler/fir/checkers/src/org/jetbrains/kotlin/fir/analysis/checkers/declaration/FirModifierChecker.kt
+++ b/compiler/fir/checkers/src/org/jetbrains/kotlin/fir/analysis/checkers/declaration/FirModifierChecker.kt
@@ -7,7 +7,10 @@ package org.jetbrains.kotlin.fir.analysis.checkers.declaration
 
 import org.jetbrains.kotlin.KtNodeTypes
 import org.jetbrains.kotlin.fir.FirSourceElement
+import org.jetbrains.kotlin.fir.analysis.checkers.FirModifier
+import org.jetbrains.kotlin.fir.analysis.checkers.FirModifierList
 import org.jetbrains.kotlin.fir.analysis.checkers.context.CheckerContext
+import org.jetbrains.kotlin.fir.analysis.checkers.getModifierList
 import org.jetbrains.kotlin.fir.analysis.diagnostics.DiagnosticReporter
 import org.jetbrains.kotlin.fir.analysis.diagnostics.FirErrors
 import org.jetbrains.kotlin.fir.declarations.*
diff --git a/compiler/fir/checkers/src/org/jetbrains/kotlin/fir/analysis/checkers/declaration/FirOpenMemberChecker.kt b/compiler/fir/checkers/src/org/jetbrains/kotlin/fir/analysis/checkers/declaration/FirOpenMemberChecker.kt
index 0d32322d13d..f9961fad874 100644
--- a/compiler/fir/checkers/src/org/jetbrains/kotlin/fir/analysis/checkers/declaration/FirOpenMemberChecker.kt
+++ b/compiler/fir/checkers/src/org/jetbrains/kotlin/fir/analysis/checkers/declaration/FirOpenMemberChecker.kt
@@ -10,6 +10,7 @@ import org.jetbrains.kotlin.fir.FirFakeSourceElementKind
 import org.jetbrains.kotlin.fir.FirRealSourceElementKind
 import org.jetbrains.kotlin.fir.FirSourceElement
 import org.jetbrains.kotlin.fir.analysis.checkers.context.CheckerContext
+import org.jetbrains.kotlin.fir.analysis.checkers.hasModifier
 import org.jetbrains.kotlin.fir.analysis.diagnostics.DiagnosticReporter
 import org.jetbrains.kotlin.fir.analysis.diagnostics.FirErrors
 import org.jetbrains.kotlin.fir.analysis.diagnostics.reportOn
diff --git a/compiler/fir/checkers/src/org/jetbrains/kotlin/fir/analysis/checkers/declaration/FirTopLevelFunctionsChecker.kt b/compiler/fir/checkers/src/org/jetbrains/kotlin/fir/analysis/checkers/declaration/FirTopLevelFunctionsChecker.kt
index 3e7577381be..eae333d17fb 100644
--- a/compiler/fir/checkers/src/org/jetbrains/kotlin/fir/analysis/checkers/declaration/FirTopLevelFunctionsChecker.kt
+++ b/compiler/fir/checkers/src/org/jetbrains/kotlin/fir/analysis/checkers/declaration/FirTopLevelFunctionsChecker.kt
@@ -7,6 +7,7 @@ package org.jetbrains.kotlin.fir.analysis.checkers.declaration
 
 import org.jetbrains.kotlin.fir.FirFakeSourceElementKind
 import org.jetbrains.kotlin.fir.analysis.checkers.context.CheckerContext
+import org.jetbrains.kotlin.fir.analysis.checkers.hasModifier
 import org.jetbrains.kotlin.fir.analysis.diagnostics.DiagnosticReporter
 import org.jetbrains.kotlin.fir.analysis.diagnostics.FirErrors
 import org.jetbrains.kotlin.fir.analysis.diagnostics.reportOn
diff --git a/compiler/fir/checkers/src/org/jetbrains/kotlin/fir/analysis/checkers/declaration/FirTopLevelPropertiesChecker.kt b/compiler/fir/checkers/src/org/jetbrains/kotlin/fir/analysis/checkers/declaration/FirTopLevelPropertiesChecker.kt
index 1c747a27d87..94ddf4b12fa 100644
--- a/compiler/fir/checkers/src/org/jetbrains/kotlin/fir/analysis/checkers/declaration/FirTopLevelPropertiesChecker.kt
+++ b/compiler/fir/checkers/src/org/jetbrains/kotlin/fir/analysis/checkers/declaration/FirTopLevelPropertiesChecker.kt
@@ -7,6 +7,7 @@ package org.jetbrains.kotlin.fir.analysis.checkers.declaration
 
 import org.jetbrains.kotlin.fir.FirFakeSourceElementKind
 import org.jetbrains.kotlin.fir.analysis.checkers.context.CheckerContext
+import org.jetbrains.kotlin.fir.analysis.checkers.getModifierList
 import org.jetbrains.kotlin.fir.analysis.diagnostics.DiagnosticReporter
 import org.jetbrains.kotlin.fir.declarations.FirFile
 import org.jetbrains.kotlin.fir.declarations.FirProperty
diff --git a/compiler/fir/checkers/src/org/jetbrains/kotlin/fir/analysis/checkers/declaration/jvm/FirJvmExternalDeclarationChecker.kt b/compiler/fir/checkers/src/org/jetbrains/kotlin/fir/analysis/checkers/declaration/jvm/FirJvmExternalDeclarationChecker.kt
index 77531f3e6b0..708388a2149 100644
--- a/compiler/fir/checkers/src/org/jetbrains/kotlin/fir/analysis/checkers/declaration/jvm/FirJvmExternalDeclarationChecker.kt
+++ b/compiler/fir/checkers/src/org/jetbrains/kotlin/fir/analysis/checkers/declaration/jvm/FirJvmExternalDeclarationChecker.kt
@@ -8,9 +8,7 @@ package org.jetbrains.kotlin.fir.analysis.checkers.declaration.jvm
 import org.jetbrains.kotlin.fir.FirFakeSourceElementKind
 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.declaration.FirModifierList
-import org.jetbrains.kotlin.fir.analysis.checkers.declaration.getModifier
-import org.jetbrains.kotlin.fir.analysis.checkers.declaration.getModifierList
+import org.jetbrains.kotlin.fir.analysis.checkers.getModifier
 import org.jetbrains.kotlin.fir.analysis.diagnostics.DiagnosticReporter
 import org.jetbrains.kotlin.fir.analysis.diagnostics.FirErrors
 import org.jetbrains.kotlin.fir.analysis.diagnostics.reportOn
diff --git a/compiler/fir/checkers/src/org/jetbrains/kotlin/fir/analysis/collectors/AbstractDiagnosticCollectorVisitor.kt b/compiler/fir/checkers/src/org/jetbrains/kotlin/fir/analysis/collectors/AbstractDiagnosticCollectorVisitor.kt
index 693903e2c19..458f2242796 100644
--- a/compiler/fir/checkers/src/org/jetbrains/kotlin/fir/analysis/collectors/AbstractDiagnosticCollectorVisitor.kt
+++ b/compiler/fir/checkers/src/org/jetbrains/kotlin/fir/analysis/collectors/AbstractDiagnosticCollectorVisitor.kt
@@ -15,11 +15,8 @@ import org.jetbrains.kotlin.fir.declarations.impl.FirDefaultPropertyAccessor
 import org.jetbrains.kotlin.fir.expressions.*
 import org.jetbrains.kotlin.fir.resolve.collectImplicitReceivers
 import org.jetbrains.kotlin.fir.resolve.defaultType
-import org.jetbrains.kotlin.fir.types.ConeKotlinType
-import org.jetbrains.kotlin.fir.types.FirResolvedTypeRef
-import org.jetbrains.kotlin.fir.types.FirTypeRef
+import org.jetbrains.kotlin.fir.types.*
 import org.jetbrains.kotlin.fir.types.builder.buildResolvedTypeRef
-import org.jetbrains.kotlin.fir.types.coneTypeSafe
 import org.jetbrains.kotlin.fir.visitors.FirDefaultVisitor
 import org.jetbrains.kotlin.name.Name