diff --git a/compiler/fir/cones/src/org/jetbrains/kotlin/fir/types/CompilerConeAttributes.kt b/compiler/fir/cones/src/org/jetbrains/kotlin/fir/types/CompilerConeAttributes.kt
index 51b77c8182b..d8bda6c5a4d 100644
--- a/compiler/fir/cones/src/org/jetbrains/kotlin/fir/types/CompilerConeAttributes.kt
+++ b/compiler/fir/cones/src/org/jetbrains/kotlin/fir/types/CompilerConeAttributes.kt
@@ -89,6 +89,11 @@ object CompilerConeAttributes {
         UnsafeVariance.ANNOTATION_CLASS_ID to UnsafeVariance
     )
 
+    val classIdByCompilerAttribute: Map<ConeAttribute<*>, ClassId> = compilerAttributeByClassId.entries.associateBy(
+        keySelector = { it.value },
+        valueTransform = { it.key }
+    )
+
     val compilerAttributeByFqName: Map<FqName, ConeAttribute<*>> = compilerAttributeByClassId.mapKeys { it.key.asSingleFqName() }
 }
 
diff --git a/compiler/fir/cones/src/org/jetbrains/kotlin/fir/types/ConeAttributes.kt b/compiler/fir/cones/src/org/jetbrains/kotlin/fir/types/ConeAttributes.kt
index 657eba11336..8e613445f7f 100644
--- a/compiler/fir/cones/src/org/jetbrains/kotlin/fir/types/ConeAttributes.kt
+++ b/compiler/fir/cones/src/org/jetbrains/kotlin/fir/types/ConeAttributes.kt
@@ -25,7 +25,7 @@ abstract class ConeAttribute<T : ConeAttribute<T>> : AnnotationMarker {
      *
      * This function must be symmetrical: a.add(b) == b.add(a)
      */
-    abstract fun add(other: @UnsafeVariance T?): T
+    abstract fun add(other: @UnsafeVariance T?): T?
     abstract fun isSubtypeOf(other: @UnsafeVariance T?): Boolean
 
     abstract override fun toString(): String
diff --git a/compiler/fir/fir-deserialization/src/org/jetbrains/kotlin/fir/deserialization/FirMemberDeserializer.kt b/compiler/fir/fir-deserialization/src/org/jetbrains/kotlin/fir/deserialization/FirMemberDeserializer.kt
index a838220f52e..cd2e42e4da7 100644
--- a/compiler/fir/fir-deserialization/src/org/jetbrains/kotlin/fir/deserialization/FirMemberDeserializer.kt
+++ b/compiler/fir/fir-deserialization/src/org/jetbrains/kotlin/fir/deserialization/FirMemberDeserializer.kt
@@ -609,7 +609,7 @@ class FirMemberDeserializer(private val c: FirDeserializationContext) {
     private fun ProtoBuf.Type.toTypeRef(context: FirDeserializationContext): FirTypeRef {
         return buildResolvedTypeRef {
             annotations += context.annotationDeserializer.loadTypeAnnotations(this@toTypeRef, context.nameResolver)
-            val attributes = annotations.computeTypeAttributes()
+            val attributes = annotations.computeTypeAttributes(context.session)
             type = context.typeDeserializer.type(this@toTypeRef, attributes)
         }
     }
diff --git a/compiler/fir/fir-deserialization/src/org/jetbrains/kotlin/fir/deserialization/FirTypeDeserializer.kt b/compiler/fir/fir-deserialization/src/org/jetbrains/kotlin/fir/deserialization/FirTypeDeserializer.kt
index 706602c0ff6..346673b8f89 100644
--- a/compiler/fir/fir-deserialization/src/org/jetbrains/kotlin/fir/deserialization/FirTypeDeserializer.kt
+++ b/compiler/fir/fir-deserialization/src/org/jetbrains/kotlin/fir/deserialization/FirTypeDeserializer.kt
@@ -109,7 +109,7 @@ class FirTypeDeserializer(
 
     fun type(proto: ProtoBuf.Type): ConeKotlinType {
         val annotations = annotationDeserializer.loadTypeAnnotations(proto, nameResolver)
-        val attributes = annotations.computeTypeAttributes()
+        val attributes = annotations.computeTypeAttributes(moduleData.session)
         return type(proto, attributes)
     }
 
diff --git a/compiler/fir/fir-serialization/src/org/jetbrains/kotlin/fir/serialization/FirElementSerializer.kt b/compiler/fir/fir-serialization/src/org/jetbrains/kotlin/fir/serialization/FirElementSerializer.kt
index 1dbe3aa0d3e..0f009be68c2 100644
--- a/compiler/fir/fir-serialization/src/org/jetbrains/kotlin/fir/serialization/FirElementSerializer.kt
+++ b/compiler/fir/fir-serialization/src/org/jetbrains/kotlin/fir/serialization/FirElementSerializer.kt
@@ -23,6 +23,8 @@ import org.jetbrains.kotlin.fir.expressions.FirExpression
 import org.jetbrains.kotlin.fir.expressions.FirNamedArgumentExpression
 import org.jetbrains.kotlin.fir.expressions.builder.buildAnnotation
 import org.jetbrains.kotlin.fir.expressions.impl.FirEmptyAnnotationArgumentMapping
+import org.jetbrains.kotlin.fir.extensions.extensionService
+import org.jetbrains.kotlin.fir.extensions.typeAttributeExtensions
 import org.jetbrains.kotlin.fir.resolve.*
 import org.jetbrains.kotlin.fir.resolve.calls.varargElementType
 import org.jetbrains.kotlin.fir.resolve.inference.isSuspendFunctionType
@@ -34,9 +36,11 @@ import org.jetbrains.kotlin.fir.serialization.constant.EnumValue
 import org.jetbrains.kotlin.fir.serialization.constant.IntValue
 import org.jetbrains.kotlin.fir.serialization.constant.StringValue
 import org.jetbrains.kotlin.fir.serialization.constant.toConstantValue
+import org.jetbrains.kotlin.fir.symbols.impl.ConeClassLikeLookupTagImpl
 import org.jetbrains.kotlin.fir.symbols.impl.FirCallableSymbol
 import org.jetbrains.kotlin.fir.types.*
 import org.jetbrains.kotlin.fir.types.builder.buildResolvedTypeRef
+import org.jetbrains.kotlin.fir.types.impl.ConeClassLikeTypeImpl
 import org.jetbrains.kotlin.fir.types.impl.FirImplicitNullableAnyTypeRef
 import org.jetbrains.kotlin.metadata.ProtoBuf
 import org.jetbrains.kotlin.metadata.deserialization.Flags
@@ -606,9 +610,41 @@ class FirElementSerializer private constructor(
     fun typeId(type: ConeKotlinType): Int = typeTable[typeProto(type)]
 
     private fun typeProto(typeRef: FirTypeRef, toSuper: Boolean = false): ProtoBuf.Type.Builder {
-        return typeProto(typeRef.coneType, toSuper, correspondingTypeRef = typeRef).also {
-            for (annotation in typeRef.annotations) {
-                extension.serializeTypeAnnotation(annotation, it)
+        val coneType = typeRef.coneType
+        return typeProto(coneType, toSuper, correspondingTypeRef = typeRef).also { typeProto ->
+            for (annotation in coneType.attributes.customAnnotations) {
+                extension.serializeTypeAnnotation(annotation, typeProto)
+            }
+
+            val compilerAttributes = mutableListOf<ConeAttribute<*>>()
+            val extensionAttributes = mutableListOf<ConeAttribute<*>>()
+            for (attribute in coneType.attributes) {
+                when (attribute) {
+                    is CustomAnnotationTypeAttribute -> continue
+                    in CompilerConeAttributes.classIdByCompilerAttribute -> compilerAttributes += attribute
+                    else -> extensionAttributes += attribute
+                }
+            }
+
+            for (attribute in compilerAttributes) {
+                val annotation = buildAnnotation {
+                    annotationTypeRef = buildResolvedTypeRef {
+                        type = ConeClassLikeTypeImpl(
+                            ConeClassLikeLookupTagImpl(CompilerConeAttributes.classIdByCompilerAttribute.getValue(attribute)),
+                            emptyArray(),
+                            isNullable = false
+                        )
+                    }
+                    argumentMapping = FirEmptyAnnotationArgumentMapping
+                }
+                extension.serializeTypeAnnotation(annotation, typeProto)
+            }
+
+            for (attributeExtension in session.extensionService.typeAttributeExtensions) {
+                for (attribute in extensionAttributes) {
+                    val annotation = attributeExtension.convertAttributeToAnnotation(attribute) ?: continue
+                    extension.serializeTypeAnnotation(annotation, typeProto)
+                }
             }
         }
     }
diff --git a/compiler/fir/resolve/src/org/jetbrains/kotlin/fir/extensions/FirExtensionRegistrar.kt b/compiler/fir/resolve/src/org/jetbrains/kotlin/fir/extensions/FirExtensionRegistrar.kt
index 78786e6880d..2be0e11d75f 100644
--- a/compiler/fir/resolve/src/org/jetbrains/kotlin/fir/extensions/FirExtensionRegistrar.kt
+++ b/compiler/fir/resolve/src/org/jetbrains/kotlin/fir/extensions/FirExtensionRegistrar.kt
@@ -15,7 +15,8 @@ abstract class FirExtensionRegistrar {
             FirStatusTransformerExtension::class,
             FirDeclarationGenerationExtension::class,
             AbstractFirAdditionalCheckersExtension::class,
-            FirSupertypeGenerationExtension::class
+            FirSupertypeGenerationExtension::class,
+            FirTypeAttributeExtension::class,
         )
     }
 
@@ -44,6 +45,11 @@ abstract class FirExtensionRegistrar {
         operator fun ((FirSession) -> FirSupertypeGenerationExtension).unaryPlus() {
             registerExtension(FirSupertypeGenerationExtension::class, FirSupertypeGenerationExtension.Factory { this.invoke(it) })
         }
+
+        @JvmName("plusTypeAttributeExtension")
+        operator fun ((FirSession) -> FirTypeAttributeExtension).unaryPlus() {
+            registerExtension(FirTypeAttributeExtension::class, FirTypeAttributeExtension.Factory { this.invoke(it) })
+        }
     }
 
     @OptIn(PluginServicesInitialization::class)
diff --git a/compiler/fir/resolve/src/org/jetbrains/kotlin/fir/resolve/providers/impl/FirTypeResolverImpl.kt b/compiler/fir/resolve/src/org/jetbrains/kotlin/fir/resolve/providers/impl/FirTypeResolverImpl.kt
index 067798f4eb9..f736b76cb07 100644
--- a/compiler/fir/resolve/src/org/jetbrains/kotlin/fir/resolve/providers/impl/FirTypeResolverImpl.kt
+++ b/compiler/fir/resolve/src/org/jetbrains/kotlin/fir/resolve/providers/impl/FirTypeResolverImpl.kt
@@ -243,13 +243,16 @@ class FirTypeResolverImpl(private val session: FirSession) : FirTypeResolver() {
             }
         }
 
-        return symbol.constructType(allTypeArguments.toTypedArray(), typeRef.isMarkedNullable, typeRef.annotations.computeTypeAttributes())
-            .also {
-                val lookupTag = it.lookupTag
-                if (lookupTag is ConeClassLikeLookupTagImpl && symbol is FirClassLikeSymbol<*>) {
-                    lookupTag.bindSymbolToLookupTag(session, symbol)
-                }
+        return symbol.constructType(
+            allTypeArguments.toTypedArray(),
+            typeRef.isMarkedNullable,
+            typeRef.annotations.computeTypeAttributes(session)
+        ).also {
+            val lookupTag = it.lookupTag
+            if (lookupTag is ConeClassLikeLookupTagImpl && symbol is FirClassLikeSymbol<*>) {
+                lookupTag.bindSymbolToLookupTag(session, symbol)
             }
+        }
     }
 
     @OptIn(SymbolInternals::class)
@@ -352,7 +355,7 @@ class FirTypeResolverImpl(private val session: FirSession) : FirTypeResolver() {
         } else {
             StandardClassIds.FunctionN(typeRef.parametersCount)
         }
-        val attributes = typeRef.annotations.computeTypeAttributes()
+        val attributes = typeRef.annotations.computeTypeAttributes(session)
         val symbol = resolveBuiltInQualified(classId, session)
         return ConeClassLikeTypeImpl(
             symbol.toLookupTag().also {
diff --git a/compiler/fir/tree/src/org/jetbrains/kotlin/fir/extensions/FirTypeAttributeExtension.kt b/compiler/fir/tree/src/org/jetbrains/kotlin/fir/extensions/FirTypeAttributeExtension.kt
new file mode 100644
index 00000000000..accce46a0c6
--- /dev/null
+++ b/compiler/fir/tree/src/org/jetbrains/kotlin/fir/extensions/FirTypeAttributeExtension.kt
@@ -0,0 +1,42 @@
+/*
+ * 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.extensions
+
+import org.jetbrains.kotlin.fir.FirSession
+import org.jetbrains.kotlin.fir.expressions.FirAnnotation
+import org.jetbrains.kotlin.fir.types.ConeAttribute
+import kotlin.reflect.KClass
+
+/**
+ * Note that when you declare your own attribute you HAVE TO declare accessor to it using following syntax:
+ *
+ * class MyAttribute : ConeAttribute<MyAttribute>() {...}
+ *
+ * val ConeAttributes.myAttribute: MyAttribute? by ConeAttributes.attributeAccessor<MyAttribute>()
+ */
+abstract class FirTypeAttributeExtension(session: FirSession) : FirExtension(session) {
+    companion object {
+        val NAME = FirExtensionPointName("AdditionalTypeAttributeExtension")
+    }
+
+    final override val name: FirExtensionPointName
+        get() = NAME
+
+    final override val extensionType: KClass<out FirExtension>
+        get() = FirTypeAttributeExtension::class
+
+    abstract fun extractAttributeFromAnnotation(annotation: FirAnnotation): ConeAttribute<*>?
+
+    /**
+     * Please don't convert attributes which you didn't create
+     * If [attribute] came from compiler or another plugin just return null
+     */
+    abstract fun convertAttributeToAnnotation(attribute: ConeAttribute<*>): FirAnnotation?
+
+    fun interface Factory : FirExtension.Factory<FirTypeAttributeExtension>
+}
+
+val FirExtensionService.typeAttributeExtensions: List<FirTypeAttributeExtension> by FirExtensionService.registeredExtensions()
diff --git a/compiler/fir/tree/src/org/jetbrains/kotlin/fir/types/FirTypeUtils.kt b/compiler/fir/tree/src/org/jetbrains/kotlin/fir/types/FirTypeUtils.kt
index 0e298b89367..02a0b376f4d 100644
--- a/compiler/fir/tree/src/org/jetbrains/kotlin/fir/types/FirTypeUtils.kt
+++ b/compiler/fir/tree/src/org/jetbrains/kotlin/fir/types/FirTypeUtils.kt
@@ -6,10 +6,13 @@
 package org.jetbrains.kotlin.fir.types
 
 import org.jetbrains.kotlin.builtins.functions.FunctionClassKind
+import org.jetbrains.kotlin.fir.FirSession
 import org.jetbrains.kotlin.fir.expressions.FirAnnotation
 import org.jetbrains.kotlin.fir.expressions.FirConstExpression
 import org.jetbrains.kotlin.fir.expressions.FirExpression
 import org.jetbrains.kotlin.fir.expressions.FirExpressionWithSmartcast
+import org.jetbrains.kotlin.fir.extensions.extensionService
+import org.jetbrains.kotlin.fir.extensions.typeAttributeExtensions
 import org.jetbrains.kotlin.fir.render
 import org.jetbrains.kotlin.fir.types.impl.FirImplicitBuiltinTypeRef
 import org.jetbrains.kotlin.name.ClassId
@@ -109,26 +112,25 @@ fun ConeClassLikeType.toConstKind(): ConstantValueKind<*>? = when (lookupTag.cla
     else -> null
 }
 
-fun List<FirAnnotation>.computeTypeAttributes(
-    additionalProcessor: MutableList<ConeAttribute<*>>.(ClassId) -> Unit = {}
-): ConeAttributes {
+fun List<FirAnnotation>.computeTypeAttributes(session: FirSession): ConeAttributes {
     if (this.isEmpty()) return ConeAttributes.Empty
     val attributes = mutableListOf<ConeAttribute<*>>()
     val customAnnotations = mutableListOf<FirAnnotation>()
     for (annotation in this) {
         val type = annotation.annotationTypeRef.coneTypeSafe<ConeClassLikeType>() ?: continue
-        when (val classId = type.lookupTag.classId) {
+        when (type.lookupTag.classId) {
             CompilerConeAttributes.Exact.ANNOTATION_CLASS_ID -> attributes += CompilerConeAttributes.Exact
             CompilerConeAttributes.NoInfer.ANNOTATION_CLASS_ID -> attributes += CompilerConeAttributes.NoInfer
             CompilerConeAttributes.ExtensionFunctionType.ANNOTATION_CLASS_ID -> attributes += CompilerConeAttributes.ExtensionFunctionType
             CompilerConeAttributes.UnsafeVariance.ANNOTATION_CLASS_ID -> attributes += CompilerConeAttributes.UnsafeVariance
             else -> {
-                val annotationAttributes = mutableListOf<ConeAttribute<*>>()
-                additionalProcessor.invoke(annotationAttributes, classId)
-                if (annotationAttributes.isEmpty()) {
-                    customAnnotations += annotation
+                val attributeFromPlugin = session.extensionService.typeAttributeExtensions.firstNotNullOfOrNull {
+                    it.extractAttributeFromAnnotation(annotation)
+                }
+                if (attributeFromPlugin != null) {
+                    attributes += attributeFromPlugin
                 } else {
-                    attributes += annotationAttributes
+                    customAnnotations += annotation
                 }
             }
         }
diff --git a/plugins/fir/fir-plugin-prototype/plugin-annotations/src/org/jetbrains/kotlin/fir/plugin/annotations.kt b/plugins/fir/fir-plugin-prototype/plugin-annotations/src/org/jetbrains/kotlin/fir/plugin/annotations.kt
index 63fb1180963..362c95641f2 100644
--- a/plugins/fir/fir-plugin-prototype/plugin-annotations/src/org/jetbrains/kotlin/fir/plugin/annotations.kt
+++ b/plugins/fir/fir-plugin-prototype/plugin-annotations/src/org/jetbrains/kotlin/fir/plugin/annotations.kt
@@ -20,6 +20,12 @@ annotation class G
 
 annotation class AllPublic(val visibility: Visibility)
 
+@Target(AnnotationTarget.TYPE)
+annotation class Positive
+
+@Target(AnnotationTarget.TYPE)
+annotation class Negative
+
 enum class Visibility {
     Public, Internal, Private, Protected
-}
\ No newline at end of file
+}
diff --git a/plugins/fir/fir-plugin-prototype/src/org/jetbrains/kotlin/fir/plugin/AllOpenAdditionalCheckers.kt b/plugins/fir/fir-plugin-prototype/src/org/jetbrains/kotlin/fir/plugin/AllOpenAdditionalCheckers.kt
index 8d918fe5bc3..d3da070ec83 100644
--- a/plugins/fir/fir-plugin-prototype/src/org/jetbrains/kotlin/fir/plugin/AllOpenAdditionalCheckers.kt
+++ b/plugins/fir/fir-plugin-prototype/src/org/jetbrains/kotlin/fir/plugin/AllOpenAdditionalCheckers.kt
@@ -8,16 +8,24 @@ package org.jetbrains.kotlin.fir.plugin
 import org.jetbrains.kotlin.fir.FirSession
 import org.jetbrains.kotlin.fir.analysis.checkers.declaration.DeclarationCheckers
 import org.jetbrains.kotlin.fir.analysis.checkers.declaration.FirSimpleFunctionChecker
+import org.jetbrains.kotlin.fir.analysis.checkers.expression.ExpressionCheckers
+import org.jetbrains.kotlin.fir.analysis.checkers.expression.FirFunctionCallChecker
 import org.jetbrains.kotlin.fir.analysis.extensions.FirAdditionalCheckersExtension
 import org.jetbrains.kotlin.fir.declarations.FirPluginKey
 import org.jetbrains.kotlin.fir.plugin.checkers.DummyNameChecker
+import org.jetbrains.kotlin.fir.plugin.checkers.SignedNumberCallChecker
 
 class AllOpenAdditionalCheckers(session: FirSession) : FirAdditionalCheckersExtension(session) {
     override val key: FirPluginKey
         get() = AllOpenPluginKey
 
     override val declarationCheckers: DeclarationCheckers = object : DeclarationCheckers() {
-                override val simpleFunctionCheckers: Set<FirSimpleFunctionChecker>
+        override val simpleFunctionCheckers: Set<FirSimpleFunctionChecker>
             get() = setOf(DummyNameChecker)
     }
+
+    override val expressionCheckers: ExpressionCheckers = object : ExpressionCheckers() {
+        override val functionCallCheckers: Set<FirFunctionCallChecker>
+            get() = setOf(SignedNumberCallChecker)
+    }
 }
diff --git a/plugins/fir/fir-plugin-prototype/src/org/jetbrains/kotlin/fir/plugin/FirAllOpenComponentRegistrar.kt b/plugins/fir/fir-plugin-prototype/src/org/jetbrains/kotlin/fir/plugin/FirAllOpenComponentRegistrar.kt
index 73cc266ad3c..fb30f377f8e 100644
--- a/plugins/fir/fir-plugin-prototype/src/org/jetbrains/kotlin/fir/plugin/FirAllOpenComponentRegistrar.kt
+++ b/plugins/fir/fir-plugin-prototype/src/org/jetbrains/kotlin/fir/plugin/FirAllOpenComponentRegistrar.kt
@@ -7,6 +7,7 @@ package org.jetbrains.kotlin.fir.plugin
 
 import org.jetbrains.kotlin.fir.extensions.FirExtensionRegistrar
 import org.jetbrains.kotlin.fir.plugin.generators.*
+import org.jetbrains.kotlin.fir.plugin.types.FirNumberSignAttributeExtension
 
 class FirAllOpenComponentRegistrar : FirExtensionRegistrar() {
     override fun ExtensionRegistrarContext.configurePlugin() {
@@ -14,6 +15,7 @@ class FirAllOpenComponentRegistrar : FirExtensionRegistrar() {
         +::AllOpenVisibilityTransformer
         +::AllOpenSupertypeGenerator
         +::AllOpenAdditionalCheckers
+        +::FirNumberSignAttributeExtension
 
         // Declaration generators
         +::AllOpenTopLevelDeclarationsGenerator
diff --git a/plugins/fir/fir-plugin-prototype/src/org/jetbrains/kotlin/fir/plugin/checkers/AllOpenErrors.kt b/plugins/fir/fir-plugin-prototype/src/org/jetbrains/kotlin/fir/plugin/checkers/AllOpenErrors.kt
index 099c3bd8825..5922a40ab77 100644
--- a/plugins/fir/fir-plugin-prototype/src/org/jetbrains/kotlin/fir/plugin/checkers/AllOpenErrors.kt
+++ b/plugins/fir/fir-plugin-prototype/src/org/jetbrains/kotlin/fir/plugin/checkers/AllOpenErrors.kt
@@ -7,8 +7,10 @@ package org.jetbrains.kotlin.fir.plugin.checkers
 
 import com.intellij.psi.PsiElement
 import org.jetbrains.kotlin.fir.analysis.diagnostics.SourceElementPositioningStrategies
+import org.jetbrains.kotlin.fir.analysis.diagnostics.error2
 import org.jetbrains.kotlin.fir.analysis.diagnostics.warning1
 
 object AllOpenErrors {
     val FUNCTION_WITH_DUMMY_NAME by warning1<PsiElement, String>(SourceElementPositioningStrategies.DECLARATION_NAME)
+    val ILLEGAL_NUMBER_SIGN by error2<PsiElement, String, String>()
 }
diff --git a/plugins/fir/fir-plugin-prototype/src/org/jetbrains/kotlin/fir/plugin/checkers/SignedNumberCallChecker.kt b/plugins/fir/fir-plugin-prototype/src/org/jetbrains/kotlin/fir/plugin/checkers/SignedNumberCallChecker.kt
new file mode 100644
index 00000000000..a587f645ede
--- /dev/null
+++ b/plugins/fir/fir-plugin-prototype/src/org/jetbrains/kotlin/fir/plugin/checkers/SignedNumberCallChecker.kt
@@ -0,0 +1,39 @@
+/*
+ * 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.plugin.checkers
+
+import org.jetbrains.kotlin.fir.analysis.checkers.context.CheckerContext
+import org.jetbrains.kotlin.fir.analysis.checkers.expression.FirFunctionCallChecker
+import org.jetbrains.kotlin.fir.analysis.diagnostics.DiagnosticReporter
+import org.jetbrains.kotlin.fir.analysis.diagnostics.InternalDiagnosticFactoryMethod
+import org.jetbrains.kotlin.fir.analysis.diagnostics.reportOn
+import org.jetbrains.kotlin.fir.analysis.diagnostics.withSuppressedDiagnostics
+import org.jetbrains.kotlin.fir.expressions.FirFunctionCall
+import org.jetbrains.kotlin.fir.expressions.argumentMapping
+import org.jetbrains.kotlin.fir.plugin.types.ConeNumberSignAttribute
+import org.jetbrains.kotlin.fir.plugin.types.numberSign
+import org.jetbrains.kotlin.fir.types.coneType
+
+object SignedNumberCallChecker : FirFunctionCallChecker() {
+    @OptIn(InternalDiagnosticFactoryMethod::class)
+    override fun check(expression: FirFunctionCall, context: CheckerContext, reporter: DiagnosticReporter) {
+        val argumentMapping = expression.argumentMapping ?: return
+        for ((argument, parameter) in argumentMapping.entries) {
+            val expectedSign = parameter.returnTypeRef.coneType.attributes.numberSign ?: continue
+            val actualSign = argument.typeRef.coneType.attributes.numberSign
+            if (expectedSign != actualSign) {
+                withSuppressedDiagnostics(argument, context) {
+                    reporter.reportOn(argument.source, AllOpenErrors.ILLEGAL_NUMBER_SIGN, expectedSign.asString(), actualSign.asString(), it)
+                }
+            }
+        }
+    }
+
+    private fun ConeNumberSignAttribute?.asString(): String = when (this?.sign) {
+        null -> "None"
+        else -> sign.name
+    }
+}
diff --git a/plugins/fir/fir-plugin-prototype/src/org/jetbrains/kotlin/fir/plugin/types/ConeNumberSignAttribute.kt b/plugins/fir/fir-plugin-prototype/src/org/jetbrains/kotlin/fir/plugin/types/ConeNumberSignAttribute.kt
new file mode 100644
index 00000000000..a4d704d8af9
--- /dev/null
+++ b/plugins/fir/fir-plugin-prototype/src/org/jetbrains/kotlin/fir/plugin/types/ConeNumberSignAttribute.kt
@@ -0,0 +1,73 @@
+/*
+ * 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.plugin.types
+
+import org.jetbrains.kotlin.fir.types.ConeAttribute
+import org.jetbrains.kotlin.fir.types.ConeAttributes
+import kotlin.reflect.KClass
+
+class ConeNumberSignAttribute private constructor(val sign: Sign) : ConeAttribute<ConeNumberSignAttribute>() {
+    companion object {
+        private val Positive = ConeNumberSignAttribute(Sign.Positive)
+        private val Negative = ConeNumberSignAttribute(Sign.Negative)
+
+        fun fromSign(sign: Sign?): ConeNumberSignAttribute? {
+            return when (sign) {
+                Sign.Positive -> Positive
+                Sign.Negative -> Negative
+                null -> null
+            }
+        }
+    }
+
+    enum class Sign {
+        Positive {
+            override fun combine(other: Sign?): Sign? = when (other) {
+                Positive -> Positive
+                Negative,
+                null -> null
+            }
+        },
+        Negative {
+            override fun combine(other: Sign?): Sign? = when (other) {
+                Negative -> Negative
+                Positive,
+                null -> null
+            }
+        };
+
+        abstract fun combine(other: Sign?): Sign?
+    }
+
+    private fun combine(other: ConeNumberSignAttribute?): ConeNumberSignAttribute? {
+        return fromSign(sign.combine(other?.sign))
+    }
+
+    override fun union(other: ConeNumberSignAttribute?): ConeNumberSignAttribute? {
+        return combine(other)
+    }
+
+    override fun intersect(other: ConeNumberSignAttribute?): ConeNumberSignAttribute? {
+        return combine(other)
+    }
+
+    override fun add(other: ConeNumberSignAttribute?): ConeNumberSignAttribute? {
+        return combine(other)
+    }
+
+    override fun isSubtypeOf(other: ConeNumberSignAttribute?): Boolean {
+        return true
+    }
+
+    override fun toString(): String {
+        return "@${sign.name}"
+    }
+
+    override val key: KClass<out ConeNumberSignAttribute>
+        get() = ConeNumberSignAttribute::class
+}
+
+val ConeAttributes.numberSign: ConeNumberSignAttribute? by ConeAttributes.attributeAccessor<ConeNumberSignAttribute>()
diff --git a/plugins/fir/fir-plugin-prototype/src/org/jetbrains/kotlin/fir/plugin/types/FirNumberSignAttributeExtension.kt b/plugins/fir/fir-plugin-prototype/src/org/jetbrains/kotlin/fir/plugin/types/FirNumberSignAttributeExtension.kt
new file mode 100644
index 00000000000..0981043c85a
--- /dev/null
+++ b/plugins/fir/fir-plugin-prototype/src/org/jetbrains/kotlin/fir/plugin/types/FirNumberSignAttributeExtension.kt
@@ -0,0 +1,62 @@
+/*
+ * 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.plugin.types
+
+import org.jetbrains.kotlin.fir.FirSession
+import org.jetbrains.kotlin.fir.declarations.FirPluginKey
+import org.jetbrains.kotlin.fir.expressions.FirAnnotation
+import org.jetbrains.kotlin.fir.expressions.builder.buildAnnotation
+import org.jetbrains.kotlin.fir.expressions.impl.FirEmptyAnnotationArgumentMapping
+import org.jetbrains.kotlin.fir.extensions.FirTypeAttributeExtension
+import org.jetbrains.kotlin.fir.plugin.AllOpenPluginKey
+import org.jetbrains.kotlin.fir.symbols.impl.ConeClassLikeLookupTagImpl
+import org.jetbrains.kotlin.fir.types.ConeAttribute
+import org.jetbrains.kotlin.fir.types.ConeClassLikeType
+import org.jetbrains.kotlin.fir.types.builder.buildResolvedTypeRef
+import org.jetbrains.kotlin.fir.types.classId
+import org.jetbrains.kotlin.fir.types.coneTypeSafe
+import org.jetbrains.kotlin.fir.types.impl.ConeClassLikeTypeImpl
+import org.jetbrains.kotlin.name.ClassId
+import org.jetbrains.kotlin.name.FqName
+import org.jetbrains.kotlin.name.Name
+
+class FirNumberSignAttributeExtension(session: FirSession) : FirTypeAttributeExtension(session) {
+    companion object {
+        private val PACKAGE_FQN = FqName("org.jetbrains.kotlin.fir.plugin")
+        private val PositiveClassId = ClassId(PACKAGE_FQN, Name.identifier("Positive"))
+        private val NegativeClassId = ClassId(PACKAGE_FQN, Name.identifier("Negative"))
+    }
+
+    override val key: FirPluginKey
+        get() = AllOpenPluginKey
+
+    override fun extractAttributeFromAnnotation(annotation: FirAnnotation): ConeAttribute<*>? {
+        val sign = when (annotation.annotationTypeRef.coneTypeSafe<ConeClassLikeType>()?.classId) {
+            PositiveClassId -> ConeNumberSignAttribute.Sign.Positive
+            NegativeClassId -> ConeNumberSignAttribute.Sign.Negative
+            else -> return null
+        }
+        return ConeNumberSignAttribute.fromSign(sign)
+    }
+
+    override fun convertAttributeToAnnotation(attribute: ConeAttribute<*>): FirAnnotation? {
+        if (attribute !is ConeNumberSignAttribute) return null
+        val classId = when (attribute.sign) {
+            ConeNumberSignAttribute.Sign.Positive -> PositiveClassId
+            ConeNumberSignAttribute.Sign.Negative -> NegativeClassId
+        }
+        return buildAnnotation {
+            annotationTypeRef = buildResolvedTypeRef {
+                type = ConeClassLikeTypeImpl(
+                    ConeClassLikeLookupTagImpl(classId),
+                    emptyArray(),
+                    isNullable = false
+                )
+            }
+            argumentMapping = FirEmptyAnnotationArgumentMapping
+        }
+    }
+}
diff --git a/plugins/fir/fir-plugin-prototype/testData/checkers/signedNumbersCheckers.fir.txt b/plugins/fir/fir-plugin-prototype/testData/checkers/signedNumbersCheckers.fir.txt
new file mode 100644
index 00000000000..94ea040886c
--- /dev/null
+++ b/plugins/fir/fir-plugin-prototype/testData/checkers/signedNumbersCheckers.fir.txt
@@ -0,0 +1,26 @@
+FILE: signedNumbersCheckers.kt
+    public final fun takePositive(x: R|@Positive kotlin/Number|): R|kotlin/Unit| {
+    }
+    public final fun takeNegative(x: R|@Negative kotlin/Number|): R|kotlin/Unit| {
+    }
+    public final fun takeAny(x: R|kotlin/Number|): R|kotlin/Unit| {
+    }
+    public final fun <K> id(x: R|K|): R|K| {
+        ^id R|<local>/x|
+    }
+    public final fun <K> select(x: R|K|, y: R|K|): R|K| {
+        ^select R|<local>/x|
+    }
+    public final fun test(positiveInt: R|@Positive kotlin/Int|, positiveDouble: R|@Positive kotlin/Double|, negativeDouble: R|@Negative kotlin/Double|): R|kotlin/Unit| {
+        R|/takePositive|(R|<local>/positiveInt|)
+        R|/takeNegative|(R|<local>/negativeDouble|)
+        R|/takeAny|(R|<local>/positiveInt|)
+        R|/takePositive|(R|<local>/negativeDouble|)
+        R|/takeNegative|(R|<local>/positiveInt|)
+        R|/takePositive|(R|/id|<R|@Positive kotlin/Int|>(R|<local>/positiveInt|))
+        R|/takeNegative|(R|/id|<R|@Positive kotlin/Int|>(R|<local>/positiveInt|))
+        R|/takePositive|(R|/select|<R|@Positive kotlin/Int|>(R|<local>/positiveInt|, R|<local>/positiveInt|))
+        R|/takePositive|(R|/select|<R|it(kotlin/Number & kotlin/Comparable<*>)|>(R|<local>/positiveInt|, R|<local>/positiveDouble|))
+        R|/takePositive|(R|/select|<R|it(kotlin/Number & kotlin/Comparable<*>)|>(R|<local>/positiveInt|, R|<local>/negativeDouble|))
+        R|/takeNegative|(R|/select|<R|it(kotlin/Number & kotlin/Comparable<*>)|>(R|<local>/positiveInt|, R|<local>/negativeDouble|))
+    }
diff --git a/plugins/fir/fir-plugin-prototype/testData/checkers/signedNumbersCheckers.kt b/plugins/fir/fir-plugin-prototype/testData/checkers/signedNumbersCheckers.kt
new file mode 100644
index 00000000000..44b67fa98b7
--- /dev/null
+++ b/plugins/fir/fir-plugin-prototype/testData/checkers/signedNumbersCheckers.kt
@@ -0,0 +1,31 @@
+import org.jetbrains.kotlin.fir.plugin.Positive
+import org.jetbrains.kotlin.fir.plugin.Negative
+
+fun takePositive(x: @Positive Number) {}
+fun takeNegative(x: @Negative Number) {}
+fun takeAny(x: Number) {}
+
+fun <K> id(x: K): K = x
+fun <K> select(x: K, y: K): K = x
+
+fun test(
+    positiveInt: @Positive Int,
+    positiveDouble: @Positive Double,
+    negativeDouble: @Negative Double
+) {
+    takePositive(positiveInt) // ok
+    takeNegative(negativeDouble) // ok
+    takeAny(positiveInt)
+
+    takePositive(<!ILLEGAL_NUMBER_SIGN!>negativeDouble<!>) // error
+    takeNegative(<!ILLEGAL_NUMBER_SIGN!>positiveInt<!>) // error
+
+    takePositive(id(positiveInt)) // ok
+    takeNegative(<!ILLEGAL_NUMBER_SIGN!>id(positiveInt)<!>) // error
+
+    takePositive(select(positiveInt, positiveInt)) // ok
+    // Should be ok, but currently attributes are not passed through common super type calculation
+    takePositive(<!ILLEGAL_NUMBER_SIGN!>select(positiveInt, positiveDouble)<!>)
+    takePositive(<!ILLEGAL_NUMBER_SIGN!>select(positiveInt, negativeDouble)<!>) // error
+    takeNegative(<!ILLEGAL_NUMBER_SIGN!>select(positiveInt, negativeDouble)<!>) // error
+}
diff --git a/plugins/fir/fir-plugin-prototype/tests-gen/org/jetbrains/kotlin/fir/plugin/FirAllOpenDiagnosticTestGenerated.java b/plugins/fir/fir-plugin-prototype/tests-gen/org/jetbrains/kotlin/fir/plugin/FirAllOpenDiagnosticTestGenerated.java
index 89591d5c3b5..9a2e95c099f 100644
--- a/plugins/fir/fir-plugin-prototype/tests-gen/org/jetbrains/kotlin/fir/plugin/FirAllOpenDiagnosticTestGenerated.java
+++ b/plugins/fir/fir-plugin-prototype/tests-gen/org/jetbrains/kotlin/fir/plugin/FirAllOpenDiagnosticTestGenerated.java
@@ -33,6 +33,12 @@ public class FirAllOpenDiagnosticTestGenerated extends AbstractFirAllOpenDiagnos
             KtTestUtil.assertAllTestsPresentByMetadataWithExcluded(this.getClass(), new File("plugins/fir/fir-plugin-prototype/testData/checkers"), Pattern.compile("^(.+)\\.kt$"), null, true);
         }
 
+        @Test
+        @TestMetadata("signedNumbersCheckers.kt")
+        public void testSignedNumbersCheckers() throws Exception {
+            runTest("plugins/fir/fir-plugin-prototype/testData/checkers/signedNumbersCheckers.kt");
+        }
+
         @Test
         @TestMetadata("simple.kt")
         public void testSimple() throws Exception {