[FIR] Implement INVALID_CHARACTERS

compiler/fir/checkers/checkers-component-generator/src/org/jetbrains/kotlin/fir/checkers/generator/diagnostics/FirDiagnosticsList.kt

@@ -1068,8 +1068,11 @@ object DIAGNOSTICS_LIST : DiagnosticList("FirErrors") {
             parameter<ConeKotlinType>("actualType")
         }
 
-        val UNDERSCORE_IS_RESERVED by error<PsiElement>(PositioningStrategy.RESERVED_UNDERSCORE)
-        val UNDERSCORE_USAGE_WITHOUT_BACKTICKS by error<PsiElement>(PositioningStrategy.RESERVED_UNDERSCORE)
+        val UNDERSCORE_IS_RESERVED by error<PsiElement>(PositioningStrategy.NAME_IDENTIFIER)
+        val UNDERSCORE_USAGE_WITHOUT_BACKTICKS by error<PsiElement>(PositioningStrategy.NAME_IDENTIFIER)
+        val INVALID_CHARACTERS by error<KtNamedDeclaration>(PositioningStrategy.NAME_IDENTIFIER) {
+            parameter<String>("message")
+        }
 
         val EQUALITY_NOT_APPLICABLE by error<KtBinaryExpression> {
             parameter<String>("operator")

compiler/fir/checkers/checkers-component-generator/src/org/jetbrains/kotlin/fir/checkers/generator/diagnostics/model/DiagnosticData.kt

@@ -69,7 +69,7 @@ enum class PositioningStrategy(private val strategy: String? = null) {
     FUN_MODIFIER,
     SUSPEND_MODIFIER,
     FUN_INTERFACE,
-    RESERVED_UNDERSCORE,
+    NAME_IDENTIFIER,
     QUESTION_MARK_BY_TYPE,
     ANNOTATION_USE_SITE,
     ASSIGNMENT_LHS,

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

@@ -554,8 +554,9 @@ object FirErrors {
     val DELEGATE_SPECIAL_FUNCTION_AMBIGUITY by error2<KtExpression, String, Collection<FirBasedSymbol<*>>>()
     val DELEGATE_SPECIAL_FUNCTION_NONE_APPLICABLE by error2<KtExpression, String, Collection<FirBasedSymbol<*>>>()
     val DELEGATE_SPECIAL_FUNCTION_RETURN_TYPE_MISMATCH by error3<KtExpression, String, ConeKotlinType, ConeKotlinType>()
-    val UNDERSCORE_IS_RESERVED by error0<PsiElement>(SourceElementPositioningStrategies.RESERVED_UNDERSCORE)
-    val UNDERSCORE_USAGE_WITHOUT_BACKTICKS by error0<PsiElement>(SourceElementPositioningStrategies.RESERVED_UNDERSCORE)
+    val UNDERSCORE_IS_RESERVED by error0<PsiElement>(SourceElementPositioningStrategies.NAME_IDENTIFIER)
+    val UNDERSCORE_USAGE_WITHOUT_BACKTICKS by error0<PsiElement>(SourceElementPositioningStrategies.NAME_IDENTIFIER)
+    val INVALID_CHARACTERS by error1<KtNamedDeclaration, String>(SourceElementPositioningStrategies.NAME_IDENTIFIER)
     val EQUALITY_NOT_APPLICABLE by error3<KtBinaryExpression, String, ConeKotlinType, ConeKotlinType>()
     val EQUALITY_NOT_APPLICABLE_WARNING by warning3<KtBinaryExpression, String, ConeKotlinType, ConeKotlinType>()
     val INCOMPATIBLE_ENUM_COMPARISON_ERROR by error2<KtElement, ConeKotlinType, ConeKotlinType>()

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

@@ -30,7 +30,8 @@ object CommonDeclarationCheckers : DeclarationCheckers() {
             FirInfixFunctionDeclarationChecker,
             FirExposedVisibilityDeclarationChecker,
             FirCyclicTypeBoundsChecker,
-            FirExpectActualDeclarationChecker
+            FirExpectActualDeclarationChecker,
+            FirInvalidCharactersChecker
         )
 
     override val functionCheckers: Set<FirFunctionChecker>

compiler/fir/checkers/src/org/jetbrains/kotlin/fir/analysis/checkers/declaration/FirInvalidCharactersChecker.kt

@@ -0,0 +1,50 @@
+/*
+ * Copyright 2010-2021 JetBrains s.r.o. and Kotlin Programming Language contributors.
+ * 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
+
+import org.jetbrains.kotlin.KtNodeTypes
+import org.jetbrains.kotlin.fir.FirFakeSourceElementKind
+import org.jetbrains.kotlin.fir.FirSourceElement
+import org.jetbrains.kotlin.fir.analysis.checkers.context.CheckerContext
+import org.jetbrains.kotlin.fir.analysis.diagnostics.DiagnosticReporter
+import org.jetbrains.kotlin.fir.analysis.diagnostics.FirErrors
+import org.jetbrains.kotlin.fir.analysis.diagnostics.reportOn
+import org.jetbrains.kotlin.fir.declarations.*
+import org.jetbrains.kotlin.name.Name
+
+object FirInvalidCharactersChecker : FirBasicDeclarationChecker() {
+    private val INVALID_CHARS = setOf('.', ';', '[', ']', '/', '<', '>', ':', '\\')
+
+    override fun check(declaration: FirDeclaration, context: CheckerContext, reporter: DiagnosticReporter) {
+        val source = declaration.source
+        when (declaration) {
+            is FirRegularClass -> checkNameAndReport(declaration.name, source, context, reporter)
+            is FirSimpleFunction -> checkNameAndReport(declaration.name, source, context, reporter)
+            is FirTypeParameter -> checkNameAndReport(declaration.name, source, context, reporter)
+            is FirProperty -> checkNameAndReport(declaration.name, source, context, reporter)
+            is FirTypeAlias -> checkNameAndReport(declaration.name, source, context, reporter)
+            is FirValueParameter -> checkNameAndReport(declaration.name, source, context, reporter)
+            else -> return
+        }
+    }
+
+    private fun checkNameAndReport(name: Name, source: FirSourceElement?, context: CheckerContext, reporter: DiagnosticReporter) {
+        val nameString = name.asString()
+        if (source != null &&
+            source.kind !is FirFakeSourceElementKind &&
+            source.elementType != KtNodeTypes.DESTRUCTURING_DECLARATION &&
+            !name.isSpecial &&
+            nameString.any { it in INVALID_CHARS }
+        ) {
+            reporter.reportOn(
+                source,
+                FirErrors.INVALID_CHARACTERS,
+                "contains illegal characters: ${INVALID_CHARS.intersect(nameString.toSet()).joinToString("")}",
+                context
+            )
+        }
+    }
+}

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

@@ -228,6 +228,7 @@ import org.jetbrains.kotlin.fir.analysis.diagnostics.FirErrors.INNER_CLASS_INSID
 import org.jetbrains.kotlin.fir.analysis.diagnostics.FirErrors.INNER_CLASS_OF_GENERIC_THROWABLE_SUBCLASS
 import org.jetbrains.kotlin.fir.analysis.diagnostics.FirErrors.INSTANCE_ACCESS_BEFORE_SUPER_CALL
 import org.jetbrains.kotlin.fir.analysis.diagnostics.FirErrors.INTERFACE_WITH_SUPERCLASS
+import org.jetbrains.kotlin.fir.analysis.diagnostics.FirErrors.INVALID_CHARACTERS
 import org.jetbrains.kotlin.fir.analysis.diagnostics.FirErrors.INVALID_IF_AS_EXPRESSION
 import org.jetbrains.kotlin.fir.analysis.diagnostics.FirErrors.INVALID_TYPE_OF_ANNOTATION_MEMBER
 import org.jetbrains.kotlin.fir.analysis.diagnostics.FirErrors.INVISIBLE_REFERENCE
@@ -1398,6 +1399,11 @@ class FirDefaultErrorMessages {
                 UNDERSCORE_USAGE_WITHOUT_BACKTICKS,
                 "Names _, __, ___, ... can be used only in back-ticks (`_`, `__`, `___`, ...)"
             )
+            map.put(
+                INVALID_CHARACTERS,
+                "Name {0}",
+                STRING
+            )
             map.put(
                 EQUALITY_NOT_APPLICABLE,
                 "Operator ''{0}'' cannot be applied to ''{1}'' and ''{2}''",

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

@@ -708,7 +708,7 @@ object LightTreePositioningStrategies {
         }
     }
 
-    val RESERVED_UNDERSCORE: LightTreePositioningStrategy = object : LightTreePositioningStrategy() {
+    val NAME_IDENTIFIER: LightTreePositioningStrategy = object : LightTreePositioningStrategy() {
         override fun mark(
             node: LighterASTNode,
             startOffset: Int,

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

@@ -238,9 +238,9 @@ object SourceElementPositioningStrategies {
         PositioningStrategies.TYPE_PARAMETERS_LIST
     )
 
-    val RESERVED_UNDERSCORE = SourceElementPositioningStrategy(
-        LightTreePositioningStrategies.RESERVED_UNDERSCORE,
-        PositioningStrategies.RESERVED_UNDERSCORE
+    val NAME_IDENTIFIER = SourceElementPositioningStrategy(
+        LightTreePositioningStrategies.NAME_IDENTIFIER,
+        PositioningStrategies.NAME_IDENTIFIER
     )
 
     val QUESTION_MARK_BY_TYPE = SourceElementPositioningStrategy(