Remove obsolete code from ModifiersChecker

Simplify existing code and move closer to usages

compiler/frontend/src/org/jetbrains/kotlin/resolve/ModifiersChecker.java

@@ -17,7 +17,6 @@
 package org.jetbrains.kotlin.resolve;
 
 import com.google.common.collect.Maps;
-import com.google.common.collect.Sets;
 import com.intellij.psi.PsiElement;
 import org.jetbrains.annotations.NotNull;
 import org.jetbrains.annotations.Nullable;
@@ -27,73 +26,20 @@ import org.jetbrains.kotlin.diagnostics.DiagnosticFactory1;
 import org.jetbrains.kotlin.extensions.DeclarationAttributeAltererExtension;
 import org.jetbrains.kotlin.lexer.KtKeywordToken;
 import org.jetbrains.kotlin.lexer.KtModifierKeywordToken;
-import org.jetbrains.kotlin.lexer.KtTokens;
 import org.jetbrains.kotlin.psi.*;
 import org.jetbrains.kotlin.resolve.checkers.DeclarationChecker;
 import org.jetbrains.kotlin.resolve.checkers.PublishedApiUsageChecker;
 import org.jetbrains.kotlin.resolve.checkers.UnderscoreChecker;
 
-import java.util.*;
+import java.util.Collection;
+import java.util.List;
+import java.util.Map;
 
 import static org.jetbrains.kotlin.diagnostics.Errors.NESTED_CLASS_NOT_ALLOWED;
 import static org.jetbrains.kotlin.diagnostics.Errors.NESTED_OBJECT_NOT_ALLOWED;
 import static org.jetbrains.kotlin.lexer.KtTokens.*;
-import static org.jetbrains.kotlin.psi.KtStubbedPsiUtil.getContainingDeclaration;
 
 public class ModifiersChecker {
-    private static final Set<KtModifierKeywordToken> MODIFIERS_ILLEGAL_ON_PARAMETERS;
-
-    static {
-        MODIFIERS_ILLEGAL_ON_PARAMETERS = Sets.newHashSet();
-        MODIFIERS_ILLEGAL_ON_PARAMETERS.addAll(Arrays.asList(KtTokens.MODIFIER_KEYWORDS_ARRAY));
-        MODIFIERS_ILLEGAL_ON_PARAMETERS.remove(KtTokens.VARARG_KEYWORD);
-    }
-
-    public static boolean isIllegalInner(@NotNull DeclarationDescriptor descriptor) {
-        return checkIllegalInner(descriptor) != InnerModifierCheckResult.ALLOWED;
-    }
-
-    private enum InnerModifierCheckResult {
-        ALLOWED,
-        ILLEGAL_POSITION,
-        IN_INTERFACE,
-        IN_OBJECT,
-    }
-
-
-    // NOTE: just checks if this is legal context for companion modifier (Companion object descriptor can be created)
-    // COMPANION_OBJECT_NOT_ALLOWED can be reported later
-    public static boolean isCompanionModifierAllowed(@NotNull KtDeclaration declaration) {
-        if (declaration instanceof KtObjectDeclaration) {
-            KtDeclaration containingDeclaration = getContainingDeclaration(declaration);
-            if (containingDeclaration instanceof KtClassOrObject) {
-                return true;
-            }
-        }
-        return false;
-    }
-
-    @NotNull
-    private static InnerModifierCheckResult checkIllegalInner(@NotNull DeclarationDescriptor descriptor) {
-        if (!(descriptor instanceof ClassDescriptor)) return InnerModifierCheckResult.ILLEGAL_POSITION;
-        ClassDescriptor classDescriptor = (ClassDescriptor) descriptor;
-
-        if (classDescriptor.getKind() != ClassKind.CLASS) return InnerModifierCheckResult.ILLEGAL_POSITION;
-
-        DeclarationDescriptor containingDeclaration = classDescriptor.getContainingDeclaration();
-        if (!(containingDeclaration instanceof ClassDescriptor)) return InnerModifierCheckResult.ILLEGAL_POSITION;
-
-        if (DescriptorUtils.isInterface(containingDeclaration)) {
-            return InnerModifierCheckResult.IN_INTERFACE;
-        }
-        else if (DescriptorUtils.isObject(containingDeclaration)) {
-            return InnerModifierCheckResult.IN_OBJECT;
-        }
-        else {
-            return InnerModifierCheckResult.ALLOWED;
-        }
-    }
-
     private static boolean isIllegalNestedClass(@NotNull DeclarationDescriptor descriptor) {
         if (!(descriptor instanceof ClassDescriptor)) return false;
         DeclarationDescriptor containingDeclaration = descriptor.getContainingDeclaration();
@@ -192,20 +138,11 @@ public class ModifiersChecker {
         return defaultVisibility;
     }
 
-    public static boolean isInnerClass(@Nullable KtModifierList modifierList) {
-        return modifierList != null && modifierList.hasModifier(INNER_KEYWORD);
-    }
-
     public class ModifiersCheckingProcedure {
-
-        @NotNull
         private final BindingTrace trace;
-        @NotNull
-        private final LanguageVersionSettings languageVersionSettings;
 
-        private ModifiersCheckingProcedure(@NotNull BindingTrace trace, LanguageVersionSettings languageVersionSettings) {
+        private ModifiersCheckingProcedure(@NotNull BindingTrace trace) {
             this.trace = trace;
-            this.languageVersionSettings = languageVersionSettings;
         }
 
         public void checkParameterHasNoValOrVar(
@@ -325,6 +262,6 @@ public class ModifiersChecker {
 
     @NotNull
     public ModifiersCheckingProcedure withTrace(@NotNull BindingTrace trace) {
-        return new ModifiersCheckingProcedure(trace, languageVersionSettings);
+        return new ModifiersCheckingProcedure(trace);
     }
 }

compiler/frontend/src/org/jetbrains/kotlin/resolve/lazy/data/KtObjectInfo.java

@@ -19,9 +19,10 @@ package org.jetbrains.kotlin.resolve.lazy.data;
 import org.jetbrains.annotations.NotNull;
 import org.jetbrains.annotations.Nullable;
 import org.jetbrains.kotlin.descriptors.ClassKind;
+import org.jetbrains.kotlin.psi.KtClassOrObject;
 import org.jetbrains.kotlin.psi.KtObjectDeclaration;
+import org.jetbrains.kotlin.psi.KtStubbedPsiUtil;
 import org.jetbrains.kotlin.psi.KtTypeParameterList;
-import org.jetbrains.kotlin.resolve.ModifiersChecker;
 
 public class KtObjectInfo extends KtClassOrObjectInfo<KtObjectDeclaration> {
     @NotNull
@@ -45,6 +46,7 @@ public class KtObjectInfo extends KtClassOrObjectInfo<KtObjectDeclaration> {
     }
 
     public boolean isCompanionObject() {
-        return element.isCompanion() && ModifiersChecker.isCompanionModifierAllowed(element);
+        return element.isCompanion() &&
+               KtStubbedPsiUtil.getContainingDeclaration(element) instanceof KtClassOrObject;
     }
 }

compiler/frontend/src/org/jetbrains/kotlin/resolve/lazy/descriptors/LazyClassDescriptor.java

@@ -34,7 +34,10 @@ import org.jetbrains.kotlin.name.Name;
 import org.jetbrains.kotlin.psi.*;
 import org.jetbrains.kotlin.psi.psiUtil.KtPsiUtilKt;
 import org.jetbrains.kotlin.psi.synthetics.SyntheticClassOrObjectDescriptor;
-import org.jetbrains.kotlin.resolve.*;
+import org.jetbrains.kotlin.resolve.BindingContext;
+import org.jetbrains.kotlin.resolve.BindingTrace;
+import org.jetbrains.kotlin.resolve.DescriptorToSourceUtils;
+import org.jetbrains.kotlin.resolve.DescriptorUtils;
 import org.jetbrains.kotlin.resolve.descriptorUtil.DescriptorUtilsKt;
 import org.jetbrains.kotlin.resolve.lazy.ForceResolveUtil;
 import org.jetbrains.kotlin.resolve.lazy.LazyClassContext;
@@ -63,8 +66,10 @@ import static kotlin.collections.CollectionsKt.firstOrNull;
 import static org.jetbrains.kotlin.descriptors.Visibilities.PRIVATE;
 import static org.jetbrains.kotlin.descriptors.Visibilities.PUBLIC;
 import static org.jetbrains.kotlin.diagnostics.Errors.*;
+import static org.jetbrains.kotlin.lexer.KtTokens.INNER_KEYWORD;
 import static org.jetbrains.kotlin.resolve.BindingContext.TYPE;
-import static org.jetbrains.kotlin.resolve.ModifiersChecker.*;
+import static org.jetbrains.kotlin.resolve.ModifiersChecker.resolveModalityFromModifiers;
+import static org.jetbrains.kotlin.resolve.ModifiersChecker.resolveVisibilityFromModifiers;
 
 public class LazyClassDescriptor extends ClassDescriptorBase implements ClassDescriptorWithResolutionScopes, LazyEntity {
     private static final Function1<KotlinType, Boolean> VALID_SUPERTYPE = type -> {
@@ -158,7 +163,7 @@ public class LazyClassDescriptor extends ClassDescriptorBase implements ClassDes
         }
         this.visibility = isLocal ? Visibilities.LOCAL : resolveVisibilityFromModifiers(modifierList, defaultVisibility);
 
-        this.isInner = isInnerClass(modifierList) && !ModifiersChecker.isIllegalInner(this);
+        this.isInner = modifierList != null && modifierList.hasModifier(INNER_KEYWORD) && !isIllegalInner(this);
         this.isData = modifierList != null && modifierList.hasModifier(KtTokens.DATA_KEYWORD);
         this.isHeader = modifierList != null && modifierList.hasModifier(KtTokens.HEADER_KEYWORD);
         this.isImpl = modifierList != null && modifierList.hasModifier(KtTokens.IMPL_KEYWORD);
@@ -258,6 +263,15 @@ public class LazyClassDescriptor extends ClassDescriptorBase implements ClassDes
         this.sealedSubclasses = storageManager.createLazyValue(() -> DescriptorUtilsKt.computeSealedSubclasses(this));
     }
 
+    private static boolean isIllegalInner(@NotNull DeclarationDescriptor descriptor) {
+        if (!DescriptorUtils.isClass(descriptor)) return true;
+
+        DeclarationDescriptor containingDeclaration = descriptor.getContainingDeclaration();
+        return !(containingDeclaration instanceof ClassDescriptor) ||
+               DescriptorUtils.isInterface(containingDeclaration) ||
+               DescriptorUtils.isObject(containingDeclaration);
+    }
+
     @NotNull
     private DeclarationDescriptor createInitializerScopeParent() {
         ConstructorDescriptor primaryConstructor = getUnsubstitutedPrimaryConstructor();