[FIR] Add contract description classes to fir

compiler/fir/psi2fir/tests/org/jetbrains/kotlin/fir/builder/AbstractRawFirBuilderTestCase.kt

@@ -15,6 +15,7 @@ import com.intellij.psi.tree.IElementType
 import com.intellij.util.PathUtil
 import org.jetbrains.kotlin.KtNodeTypes
 import org.jetbrains.kotlin.fir.*
+import org.jetbrains.kotlin.fir.contracts.impl.FirEmptyContractDescription
 import org.jetbrains.kotlin.fir.declarations.FirFile
 import org.jetbrains.kotlin.fir.declarations.FirResolvePhase
 import org.jetbrains.kotlin.fir.expressions.FirWrappedDelegateExpression
@@ -129,7 +130,7 @@ abstract class AbstractRawFirBuilderTestCase : KtParsingTestCase(
         override fun visitElement(element: FirElement) {
             // NB: types are reused sometimes (e.g. in accessors)
             if (!result.add(element)) {
-                if (element !is FirTypeRef && element !is FirNoReceiverExpression) {
+                if (element !is FirTypeRef && element !is FirNoReceiverExpression && element !is FirEmptyContractDescription) {
                     val elementDump = StringBuilder().also { element.accept(FirRenderer(it)) }.toString()
                     throw AssertionError("FirElement ${element.javaClass} is visited twice: $elementDump")
                 }
@@ -146,7 +147,7 @@ abstract class AbstractRawFirBuilderTestCase : KtParsingTestCase(
 
         override fun <E : FirElement> transformElement(element: E, data: Unit): CompositeTransformResult<E> {
             if (!result.add(element)) {
-                if (element !is FirTypeRef && element !is FirNoReceiverExpression) {
+                if (element !is FirTypeRef && element !is FirNoReceiverExpression && element !is FirEmptyContractDescription) {
                     val elementDump = StringBuilder().also { element.accept(FirRenderer(it)) }.toString()
                     throw AssertionError("FirElement ${element.javaClass} is visited twice: $elementDump")
                 }

compiler/fir/tree/src/org/jetbrains/kotlin/fir/contracts/FirContractDescription.kt

@@ -0,0 +1,24 @@
+/*
+ * Copyright 2010-2019 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.contracts
+
+import com.intellij.psi.PsiElement
+import org.jetbrains.kotlin.fir.FirElement
+import org.jetbrains.kotlin.fir.FirPureAbstractElement
+import org.jetbrains.kotlin.fir.contracts.description.ConeEffectDeclaration
+import org.jetbrains.kotlin.fir.visitors.*
+
+/*
+ * This file was generated automatically
+ * DO NOT MODIFY IT MANUALLY
+ */
+
+abstract class FirContractDescription : FirPureAbstractElement(), FirElement {
+    abstract override val psi: PsiElement?
+    abstract val effects: List<ConeEffectDeclaration>
+
+    override fun <R, D> accept(visitor: FirVisitor<R, D>, data: D): R = visitor.visitContractDescription(this, data)
+}

compiler/fir/tree/src/org/jetbrains/kotlin/fir/contracts/description/ConeContractDescription.kt

@@ -0,0 +1,20 @@
+/*
+ * Copyright 2010-2019 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.contracts.description
+
+interface ConeContractDescriptionElement {
+    fun <R, D> accept(contractDescriptionVisitor: ConeContractDescriptionVisitor<R, D>, data: D): R
+}
+
+interface ConeEffectDeclaration : ConeContractDescriptionElement {
+    override fun <R, D> accept(contractDescriptionVisitor: ConeContractDescriptionVisitor<R, D>, data: D): R =
+        contractDescriptionVisitor.visitEffectDeclaration(this, data)
+}
+
+interface ConeBooleanExpression : ConeContractDescriptionElement {
+    override fun <R, D> accept(contractDescriptionVisitor: ConeContractDescriptionVisitor<R, D>, data: D): R =
+        contractDescriptionVisitor.visitBooleanExpression(this, data)
+}

compiler/fir/tree/src/org/jetbrains/kotlin/fir/contracts/description/ConeContractDescriptionVisitor.kt

@@ -0,0 +1,53 @@
+/*
+ * Copyright 2010-2019 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.contracts.description
+
+
+abstract class ConeContractDescriptionVisitor<out R, in D> {
+    open fun visitContractDescriptionElement(contractDescriptionElement: ConeContractDescriptionElement, data: D): R {
+        throw IllegalStateException("Top of hierarchy reached, no overloads were found for element: $contractDescriptionElement")
+    }
+
+    // Effects
+    open fun visitEffectDeclaration(effectDeclaration: ConeEffectDeclaration, data: D): R = visitContractDescriptionElement(effectDeclaration, data)
+
+    open fun visitConditionalEffectDeclaration(conditionalEffect: ConeConditionalEffectDeclaration, data: D): R =
+        visitEffectDeclaration(conditionalEffect, data)
+
+    open fun visitReturnsEffectDeclaration(returnsEffect: ConeReturnsEffectDeclaration, data: D): R =
+        visitEffectDeclaration(returnsEffect, data)
+
+    open fun visitCallsEffectDeclaration(callsEffect: ConeCallsEffectDeclaration, data: D): R =
+        visitEffectDeclaration(callsEffect, data)
+
+    // Expressions
+    open fun visitBooleanExpression(booleanExpression: ConeBooleanExpression, data: D): R =
+        visitContractDescriptionElement(booleanExpression, data)
+
+    open fun visitLogicalBinaryOperationContractExpression(binaryLogicExpression: ConeBinaryLogicExpression, data: D): R =
+        visitBooleanExpression(binaryLogicExpression, data)
+
+    open fun visitLogicalNot(logicalNot: ConeLogicalNot, data: D): R = visitBooleanExpression(logicalNot, data)
+
+    open fun visitIsInstancePredicate(isInstancePredicate: ConeIsInstancePredicate, data: D): R =
+        visitBooleanExpression(isInstancePredicate, data)
+
+    open fun visitIsNullPredicate(isNullPredicate: ConeIsNullPredicate, data: D): R = visitBooleanExpression(isNullPredicate, data)
+
+    // Values
+    open fun visitValue(value: ConeContractDescriptionValue, data: D): R = visitContractDescriptionElement(value, data)
+
+    open fun visitConstantDescriptor(constantReference: ConeConstantReference, data: D): R = visitValue(constantReference, data)
+
+    open fun visitBooleanConstantDescriptor(booleanConstantDescriptor: ConeBooleanConstantReference, data: D): R =
+        visitConstantDescriptor(booleanConstantDescriptor, data)
+
+    open fun visitValueParameterReference(valueParameterReference: ConeValueParameterReference, data: D): R =
+        visitValue(valueParameterReference, data)
+
+   open fun visitBooleanValueParameterReference(booleanValueParameterReference: ConeBooleanValueParameterReference, data: D): R =
+        visitValueParameterReference(booleanValueParameterReference, data)
+}

compiler/fir/tree/src/org/jetbrains/kotlin/fir/contracts/description/ConeEffects.kt

@@ -0,0 +1,47 @@
+/*
+ * Copyright 2010-2019 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.contracts.description
+
+import org.jetbrains.kotlin.contracts.description.InvocationKind
+
+/**
+ * Effect with condition attached to it.
+ *
+ * [condition] is some expression, which result-type is Boolean, and clause should
+ * be interpreted as: "if [effect] took place then [condition]-expression is
+ * guaranteed to be true"
+ *
+ * NB. [effect] and [condition] connected with implication in math logic sense:
+ * [effect] => [condition]. In particular this means that:
+ *  - there can be multiple ways how [effect] can be produced, but for any of them
+ *    [condition] holds.
+ *  - if [effect] wasn't observed, we *can't* reason that [condition] is false
+ *  - if [condition] is true, we *can't* reason that [effect] will be observed.
+ */
+class ConeConditionalEffectDeclaration(val effect: ConeEffectDeclaration, val condition: ConeBooleanExpression) : ConeEffectDeclaration {
+    override fun <R, D> accept(contractDescriptionVisitor: ConeContractDescriptionVisitor<R, D>, data: D): R =
+        contractDescriptionVisitor.visitConditionalEffectDeclaration(this, data)
+}
+
+
+/**
+ * Effect which specifies that subroutine returns some particular value
+ */
+class ConeReturnsEffectDeclaration(val value: ConeConstantReference) : ConeEffectDeclaration {
+    override fun <R, D> accept(contractDescriptionVisitor: ConeContractDescriptionVisitor<R, D>, data: D): R =
+        contractDescriptionVisitor.visitReturnsEffectDeclaration(this, data)
+
+}
+
+
+/**
+ * Effect which specifies, that during execution of subroutine, callable [valueParameterReference] will be invoked
+ * [kind] amount of times, and will never be invoked after subroutine call is finished.
+ */
+class ConeCallsEffectDeclaration(val valueParameterReference: ConeValueParameterReference, val kind: InvocationKind) : ConeEffectDeclaration {
+    override fun <R, D> accept(contractDescriptionVisitor: ConeContractDescriptionVisitor<R, D>, data: D): R =
+        contractDescriptionVisitor.visitCallsEffectDeclaration(this, data)
+}

compiler/fir/tree/src/org/jetbrains/kotlin/fir/contracts/description/ConeLogicalCombinators.kt

@@ -0,0 +1,19 @@
+/*
+ * Copyright 2010-2019 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.contracts.description
+
+import org.jetbrains.kotlin.fir.expressions.LogicOperationKind
+
+class ConeBinaryLogicExpression(val left: ConeBooleanExpression, val right: ConeBooleanExpression, val kind: LogicOperationKind) : ConeBooleanExpression {
+    override fun <R, D> accept(contractDescriptionVisitor: ConeContractDescriptionVisitor<R, D>, data: D): R {
+        return contractDescriptionVisitor.visitLogicalBinaryOperationContractExpression(this, data)
+    }
+}
+
+class ConeLogicalNot(val arg: ConeBooleanExpression) : ConeBooleanExpression {
+    override fun <R, D> accept(contractDescriptionVisitor: ConeContractDescriptionVisitor<R, D>, data: D): R =
+        contractDescriptionVisitor.visitLogicalNot(this, data)
+}

compiler/fir/tree/src/org/jetbrains/kotlin/fir/contracts/description/ConePredicates.kt

@@ -0,0 +1,24 @@
+/*
+ * Copyright 2010-2019 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.contracts.description
+
+import org.jetbrains.kotlin.fir.types.ConeKotlinType
+
+class ConeIsInstancePredicate(val arg: ConeValueParameterReference, val type: ConeKotlinType, val isNegated: Boolean) : ConeBooleanExpression {
+    override fun <R, D> accept(contractDescriptionVisitor: ConeContractDescriptionVisitor<R, D>, data: D): R =
+        contractDescriptionVisitor.visitIsInstancePredicate(this, data)
+
+    fun negated(): ConeIsInstancePredicate =
+        ConeIsInstancePredicate(arg, type, isNegated.not())
+}
+
+class ConeIsNullPredicate(val arg: ConeValueParameterReference, val isNegated: Boolean) : ConeBooleanExpression {
+    override fun <R, D> accept(contractDescriptionVisitor: ConeContractDescriptionVisitor<R, D>, data: D): R =
+        contractDescriptionVisitor.visitIsNullPredicate(this, data)
+
+    fun negated(): ConeIsNullPredicate =
+        ConeIsNullPredicate(arg, isNegated.not())
+}

compiler/fir/tree/src/org/jetbrains/kotlin/fir/contracts/description/ConeValues.kt

@@ -0,0 +1,50 @@
+/*
+ * Copyright 2010-2019 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.contracts.description
+
+interface ConeContractDescriptionValue : ConeContractDescriptionElement {
+    override fun <R, D> accept(contractDescriptionVisitor: ConeContractDescriptionVisitor<R, D>, data: D): R =
+        contractDescriptionVisitor.visitValue(this, data)
+}
+
+open class ConeConstantReference protected constructor(val name: String) : ConeContractDescriptionValue {
+    override fun <R, D> accept(contractDescriptionVisitor: ConeContractDescriptionVisitor<R, D>, data: D): R =
+        contractDescriptionVisitor.visitConstantDescriptor(this, data)
+
+    companion object {
+        val NULL = ConeConstantReference("NULL")
+        val WILDCARD = ConeConstantReference("WILDCARD")
+        val NOT_NULL = ConeConstantReference("NOT_NULL")
+    }
+}
+
+class ConeBooleanConstantReference private constructor(name: String) : ConeConstantReference(name), ConeBooleanExpression {
+    override fun <R, D> accept(contractDescriptionVisitor: ConeContractDescriptionVisitor<R, D>, data: D): R =
+        contractDescriptionVisitor.visitBooleanConstantDescriptor(this, data)
+
+    companion object {
+        val TRUE = ConeBooleanConstantReference("TRUE")
+        val FALSE = ConeBooleanConstantReference("FALSE")
+    }
+}
+
+/*
+ * Index of value parameter of function
+ * -1 means that it is reference to extension receiver
+ */
+open class ConeValueParameterReference(val parameterIndex: Int) : ConeContractDescriptionValue {
+    init {
+        assert(parameterIndex >= -1)
+    }
+
+    override fun <R, D> accept(contractDescriptionVisitor: ConeContractDescriptionVisitor<R, D>, data: D): R =
+        contractDescriptionVisitor.visitValueParameterReference(this, data)
+}
+
+class ConeBooleanValueParameterReference(parameterIndex: Int) : ConeValueParameterReference(parameterIndex), ConeBooleanExpression {
+    override fun <R, D> accept(contractDescriptionVisitor: ConeContractDescriptionVisitor<R, D>, data: D): R =
+        contractDescriptionVisitor.visitBooleanValueParameterReference(this, data)
+}

compiler/fir/tree/src/org/jetbrains/kotlin/fir/contracts/impl/FirContractDescriptionImpl.kt

@@ -0,0 +1,28 @@
+/*
+ * Copyright 2010-2019 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.contracts.impl
+
+import com.intellij.psi.PsiElement
+import org.jetbrains.kotlin.fir.contracts.FirContractDescription
+import org.jetbrains.kotlin.fir.contracts.description.ConeEffectDeclaration
+import org.jetbrains.kotlin.fir.visitors.*
+
+/*
+ * This file was generated automatically
+ * DO NOT MODIFY IT MANUALLY
+ */
+
+class FirContractDescriptionImpl(
+    override val psi: PsiElement?
+) : FirContractDescription() {
+    override val effects: MutableList<ConeEffectDeclaration> = mutableListOf()
+
+    override fun <R, D> acceptChildren(visitor: FirVisitor<R, D>, data: D) {}
+
+    override fun <D> transformChildren(transformer: FirTransformer<D>, data: D): FirContractDescriptionImpl {
+        return this
+    }
+}

compiler/fir/tree/src/org/jetbrains/kotlin/fir/contracts/impl/FirEmptyContractDescription.kt

@@ -0,0 +1,23 @@
+/*
+ * Copyright 2010-2019 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.contracts.impl
+
+import com.intellij.psi.PsiElement
+import org.jetbrains.kotlin.fir.contracts.FirContractDescription
+import org.jetbrains.kotlin.fir.contracts.description.ConeEffectDeclaration
+import org.jetbrains.kotlin.fir.visitors.FirTransformer
+import org.jetbrains.kotlin.fir.visitors.FirVisitor
+
+object FirEmptyContractDescription : FirContractDescription() {
+    override val psi: PsiElement? get() = null
+    override val effects: List<ConeEffectDeclaration> get() = emptyList()
+
+    override fun <R, D> acceptChildren(visitor: FirVisitor<R, D>, data: D) {}
+
+    override fun <D> transformChildren(transformer: FirTransformer<D>, data: D): FirContractDescription {
+        return this
+    }
+}

compiler/fir/tree/src/org/jetbrains/kotlin/fir/declarations/FirContractDescriptionOwner.kt

@@ -0,0 +1,25 @@
+/*
+ * Copyright 2010-2019 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.declarations
+
+import com.intellij.psi.PsiElement
+import org.jetbrains.kotlin.fir.FirElement
+import org.jetbrains.kotlin.fir.contracts.FirContractDescription
+import org.jetbrains.kotlin.fir.visitors.*
+
+/*
+ * This file was generated automatically
+ * DO NOT MODIFY IT MANUALLY
+ */
+
+interface FirContractDescriptionOwner : FirElement {
+    override val psi: PsiElement?
+    val contractDescription: FirContractDescription
+
+    override fun <R, D> accept(visitor: FirVisitor<R, D>, data: D): R = visitor.visitContractDescriptionOwner(this, data)
+
+    fun <D> transformContractDescription(transformer: FirTransformer<D>, data: D): FirContractDescriptionOwner
+}

compiler/fir/tree/src/org/jetbrains/kotlin/fir/declarations/FirPropertyAccessor.kt

@@ -8,6 +8,7 @@ package org.jetbrains.kotlin.fir.declarations
 import com.intellij.psi.PsiElement
 import org.jetbrains.kotlin.fir.FirPureAbstractElement
 import org.jetbrains.kotlin.fir.FirSession
+import org.jetbrains.kotlin.fir.contracts.FirContractDescription
 import org.jetbrains.kotlin.fir.expressions.FirAnnotationCall
 import org.jetbrains.kotlin.fir.expressions.FirBlock
 import org.jetbrains.kotlin.fir.references.FirControlFlowGraphReference
@@ -20,7 +21,7 @@ import org.jetbrains.kotlin.fir.visitors.*
  * DO NOT MODIFY IT MANUALLY
  */
 
-abstract class FirPropertyAccessor : FirPureAbstractElement(), FirFunction<FirPropertyAccessor> {
+abstract class FirPropertyAccessor : FirPureAbstractElement(), FirFunction<FirPropertyAccessor>, FirContractDescriptionOwner {
     abstract override val psi: PsiElement?
     abstract override val session: FirSession
     abstract override val resolvePhase: FirResolvePhase
@@ -30,6 +31,7 @@ abstract class FirPropertyAccessor : FirPureAbstractElement(), FirFunction<FirPr
     abstract override val typeParameters: List<FirTypeParameter>
     abstract override val valueParameters: List<FirValueParameter>
     abstract override val body: FirBlock?
+    abstract override val contractDescription: FirContractDescription
     abstract override val symbol: FirPropertyAccessorSymbol
     abstract val isGetter: Boolean
     abstract val isSetter: Boolean
@@ -43,4 +45,6 @@ abstract class FirPropertyAccessor : FirPureAbstractElement(), FirFunction<FirPr
     abstract override fun <D> transformControlFlowGraphReference(transformer: FirTransformer<D>, data: D): FirPropertyAccessor
 
     abstract override fun <D> transformValueParameters(transformer: FirTransformer<D>, data: D): FirPropertyAccessor
+
+    abstract override fun <D> transformContractDescription(transformer: FirTransformer<D>, data: D): FirPropertyAccessor
 }

compiler/fir/tree/src/org/jetbrains/kotlin/fir/declarations/FirSimpleFunction.kt

@@ -8,6 +8,7 @@ package org.jetbrains.kotlin.fir.declarations
 import com.intellij.psi.PsiElement
 import org.jetbrains.kotlin.fir.FirPureAbstractElement
 import org.jetbrains.kotlin.fir.FirSession
+import org.jetbrains.kotlin.fir.contracts.FirContractDescription
 import org.jetbrains.kotlin.fir.expressions.FirAnnotationCall
 import org.jetbrains.kotlin.fir.expressions.FirBlock
 import org.jetbrains.kotlin.fir.references.FirControlFlowGraphReference
@@ -22,7 +23,7 @@ import org.jetbrains.kotlin.fir.visitors.*
  * DO NOT MODIFY IT MANUALLY
  */
 
-abstract class FirSimpleFunction : FirPureAbstractElement(), FirMemberFunction<FirSimpleFunction> {
+abstract class FirSimpleFunction : FirPureAbstractElement(), FirMemberFunction<FirSimpleFunction>, FirContractDescriptionOwner {
     abstract override val psi: PsiElement?
     abstract override val session: FirSession
     abstract override val resolvePhase: FirResolvePhase
@@ -37,6 +38,7 @@ abstract class FirSimpleFunction : FirPureAbstractElement(), FirMemberFunction<F
     abstract override val containerSource: DeserializedContainerSource?
     abstract override val symbol: FirFunctionSymbol<FirSimpleFunction>
     abstract override val annotations: List<FirAnnotationCall>
+    abstract override val contractDescription: FirContractDescription
 
     override fun <R, D> accept(visitor: FirVisitor<R, D>, data: D): R = visitor.visitSimpleFunction(this, data)
 
@@ -45,4 +47,6 @@ abstract class FirSimpleFunction : FirPureAbstractElement(), FirMemberFunction<F
     abstract override fun <D> transformControlFlowGraphReference(transformer: FirTransformer<D>, data: D): FirSimpleFunction
 
     abstract override fun <D> transformValueParameters(transformer: FirTransformer<D>, data: D): FirSimpleFunction
+
+    abstract override fun <D> transformContractDescription(transformer: FirTransformer<D>, data: D): FirSimpleFunction
 }

compiler/fir/tree/src/org/jetbrains/kotlin/fir/declarations/impl/FirPropertyAccessorImpl.kt

@@ -8,6 +8,8 @@ package org.jetbrains.kotlin.fir.declarations.impl
 import com.intellij.psi.PsiElement
 import org.jetbrains.kotlin.descriptors.Modality
 import org.jetbrains.kotlin.fir.FirSession
+import org.jetbrains.kotlin.fir.contracts.FirContractDescription
+import org.jetbrains.kotlin.fir.contracts.impl.FirEmptyContractDescription
 import org.jetbrains.kotlin.fir.declarations.FirDeclarationStatus
 import org.jetbrains.kotlin.fir.declarations.FirPropertyAccessor
 import org.jetbrains.kotlin.fir.declarations.FirResolvePhase
@@ -41,6 +43,7 @@ open class FirPropertyAccessorImpl(
     override val typeParameters: MutableList<FirTypeParameter> = mutableListOf()
     override val valueParameters: MutableList<FirValueParameter> = mutableListOf()
     override var body: FirBlock? = null
+    override var contractDescription: FirContractDescription = FirEmptyContractDescription
     override val isSetter: Boolean get() = !isGetter
     override val annotations: MutableList<FirAnnotationCall> = mutableListOf()
 
@@ -55,6 +58,7 @@ open class FirPropertyAccessorImpl(
         typeParameters.forEach { it.accept(visitor, data) }
         valueParameters.forEach { it.accept(visitor, data) }
         body?.accept(visitor, data)
+        contractDescription.accept(visitor, data)
         status.accept(visitor, data)
         annotations.forEach { it.accept(visitor, data) }
     }
@@ -66,6 +70,7 @@ open class FirPropertyAccessorImpl(
         typeParameters.transformInplace(transformer, data)
         transformValueParameters(transformer, data)
         body = body?.transformSingle(transformer, data)
+        transformContractDescription(transformer, data)
         status = status.transformSingle(transformer, data)
         annotations.transformInplace(transformer, data)
         return this
@@ -86,6 +91,11 @@ open class FirPropertyAccessorImpl(
         return this
     }
 
+    override fun <D> transformContractDescription(transformer: FirTransformer<D>, data: D): FirPropertyAccessorImpl {
+        contractDescription = contractDescription.transformSingle(transformer, data)
+        return this
+    }
+
     override fun replaceResolvePhase(newResolvePhase: FirResolvePhase) {
         resolvePhase = newResolvePhase
     }

compiler/fir/tree/src/org/jetbrains/kotlin/fir/declarations/impl/FirSimpleFunctionImpl.kt

@@ -7,6 +7,8 @@ package org.jetbrains.kotlin.fir.declarations.impl
 
 import com.intellij.psi.PsiElement
 import org.jetbrains.kotlin.fir.FirSession
+import org.jetbrains.kotlin.fir.contracts.FirContractDescription
+import org.jetbrains.kotlin.fir.contracts.impl.FirEmptyContractDescription
 import org.jetbrains.kotlin.fir.declarations.FirDeclarationStatus
 import org.jetbrains.kotlin.fir.declarations.FirResolvePhase
 import org.jetbrains.kotlin.fir.declarations.FirSimpleFunction
@@ -44,6 +46,7 @@ open class FirSimpleFunctionImpl(
     override var body: FirBlock? = null
     override var containerSource: DeserializedContainerSource? = null
     override val annotations: MutableList<FirAnnotationCall> = mutableListOf()
+    override var contractDescription: FirContractDescription = FirEmptyContractDescription
 
     init {
         symbol.bind(this)
@@ -58,6 +61,7 @@ open class FirSimpleFunctionImpl(
         body?.accept(visitor, data)
         status.accept(visitor, data)
         annotations.forEach { it.accept(visitor, data) }
+        contractDescription.accept(visitor, data)
     }
 
     override fun <D> transformChildren(transformer: FirTransformer<D>, data: D): FirSimpleFunctionImpl {
@@ -69,6 +73,7 @@ open class FirSimpleFunctionImpl(
         body = body?.transformSingle(transformer, data)
         status = status.transformSingle(transformer, data)
         annotations.transformInplace(transformer, data)
+        transformContractDescription(transformer, data)
         return this
     }
 
@@ -87,6 +92,11 @@ open class FirSimpleFunctionImpl(
         return this
     }
 
+    override fun <D> transformContractDescription(transformer: FirTransformer<D>, data: D): FirSimpleFunctionImpl {
+        contractDescription = contractDescription.transformSingle(transformer, data)
+        return this
+    }
+
     override fun replaceResolvePhase(newResolvePhase: FirResolvePhase) {
         resolvePhase = newResolvePhase
     }

compiler/fir/tree/src/org/jetbrains/kotlin/fir/visitors/FirTransformer.kt

@@ -40,6 +40,7 @@ import org.jetbrains.kotlin.fir.declarations.FirSealedClass
 import org.jetbrains.kotlin.fir.declarations.FirTypeAlias
 import org.jetbrains.kotlin.fir.declarations.FirEnumEntry
 import org.jetbrains.kotlin.fir.declarations.FirFunction
+import org.jetbrains.kotlin.fir.declarations.FirContractDescriptionOwner
 import org.jetbrains.kotlin.fir.declarations.FirMemberFunction
 import org.jetbrains.kotlin.fir.declarations.FirSimpleFunction
 import org.jetbrains.kotlin.fir.declarations.FirPropertyAccessor
@@ -113,6 +114,7 @@ import org.jetbrains.kotlin.fir.types.FirDynamicTypeRef
 import org.jetbrains.kotlin.fir.types.FirFunctionTypeRef
 import org.jetbrains.kotlin.fir.types.FirResolvedFunctionTypeRef
 import org.jetbrains.kotlin.fir.types.FirImplicitTypeRef
+import org.jetbrains.kotlin.fir.contracts.FirContractDescription
 import org.jetbrains.kotlin.fir.visitors.CompositeTransformResult
 
 /*
@@ -260,6 +262,10 @@ abstract class FirTransformer<in D> : FirVisitor<CompositeTransformResult<FirEle
         return transformElement(function, data)
     }
 
+    open fun transformContractDescriptionOwner(contractDescriptionOwner: FirContractDescriptionOwner, data: D): CompositeTransformResult<FirContractDescriptionOwner> {
+        return transformElement(contractDescriptionOwner, data)
+    }
+
     open fun <F : FirMemberFunction<F>> transformMemberFunction(memberFunction: FirMemberFunction<F>, data: D): CompositeTransformResult<FirDeclaration> {
         return transformElement(memberFunction, data)
     }
@@ -552,6 +558,10 @@ abstract class FirTransformer<in D> : FirVisitor<CompositeTransformResult<FirEle
         return transformElement(implicitTypeRef, data)
     }
 
+    open fun transformContractDescription(contractDescription: FirContractDescription, data: D): CompositeTransformResult<FirContractDescription> {
+        return transformElement(contractDescription, data)
+    }
+
     final override fun visitElement(element: FirElement, data: D): CompositeTransformResult<FirElement> {
         return transformElement(element, data)
     }
@@ -692,6 +702,10 @@ abstract class FirTransformer<in D> : FirVisitor<CompositeTransformResult<FirEle
         return transformFunction(function, data)
     }
 
+    final override fun visitContractDescriptionOwner(contractDescriptionOwner: FirContractDescriptionOwner, data: D): CompositeTransformResult<FirContractDescriptionOwner> {
+        return transformContractDescriptionOwner(contractDescriptionOwner, data)
+    }
+
     final override fun <F : FirMemberFunction<F>> visitMemberFunction(memberFunction: FirMemberFunction<F>, data: D): CompositeTransformResult<FirDeclaration> {
         return transformMemberFunction(memberFunction, data)
     }
@@ -984,4 +998,8 @@ abstract class FirTransformer<in D> : FirVisitor<CompositeTransformResult<FirEle
         return transformImplicitTypeRef(implicitTypeRef, data)
     }
 
+    final override fun visitContractDescription(contractDescription: FirContractDescription, data: D): CompositeTransformResult<FirContractDescription> {
+        return transformContractDescription(contractDescription, data)
+    }
+
 }

compiler/fir/tree/src/org/jetbrains/kotlin/fir/visitors/FirVisitor.kt

@@ -40,6 +40,7 @@ import org.jetbrains.kotlin.fir.declarations.FirSealedClass
 import org.jetbrains.kotlin.fir.declarations.FirTypeAlias
 import org.jetbrains.kotlin.fir.declarations.FirEnumEntry
 import org.jetbrains.kotlin.fir.declarations.FirFunction
+import org.jetbrains.kotlin.fir.declarations.FirContractDescriptionOwner
 import org.jetbrains.kotlin.fir.declarations.FirMemberFunction
 import org.jetbrains.kotlin.fir.declarations.FirSimpleFunction
 import org.jetbrains.kotlin.fir.declarations.FirPropertyAccessor
@@ -113,6 +114,7 @@ import org.jetbrains.kotlin.fir.types.FirDynamicTypeRef
 import org.jetbrains.kotlin.fir.types.FirFunctionTypeRef
 import org.jetbrains.kotlin.fir.types.FirResolvedFunctionTypeRef
 import org.jetbrains.kotlin.fir.types.FirImplicitTypeRef
+import org.jetbrains.kotlin.fir.contracts.FirContractDescription
 
 /*
  * This file was generated automatically
@@ -190,6 +192,8 @@ abstract class FirVisitor<out R, in D> {
 
     open fun <F : FirFunction<F>> visitFunction(function: FirFunction<F>, data: D): R  = visitElement(function, data)
 
+    open fun visitContractDescriptionOwner(contractDescriptionOwner: FirContractDescriptionOwner, data: D): R  = visitElement(contractDescriptionOwner, data)
+
     open fun <F : FirMemberFunction<F>> visitMemberFunction(memberFunction: FirMemberFunction<F>, data: D): R  = visitElement(memberFunction, data)
 
     open fun visitSimpleFunction(simpleFunction: FirSimpleFunction, data: D): R  = visitElement(simpleFunction, data)
@@ -336,4 +340,6 @@ abstract class FirVisitor<out R, in D> {
 
     open fun visitImplicitTypeRef(implicitTypeRef: FirImplicitTypeRef, data: D): R  = visitElement(implicitTypeRef, data)
 
+    open fun visitContractDescription(contractDescription: FirContractDescription, data: D): R  = visitElement(contractDescription, data)
+
 }

compiler/fir/tree/src/org/jetbrains/kotlin/fir/visitors/FirVisitorVoid.kt

@@ -40,6 +40,7 @@ import org.jetbrains.kotlin.fir.declarations.FirSealedClass
 import org.jetbrains.kotlin.fir.declarations.FirTypeAlias
 import org.jetbrains.kotlin.fir.declarations.FirEnumEntry
 import org.jetbrains.kotlin.fir.declarations.FirFunction
+import org.jetbrains.kotlin.fir.declarations.FirContractDescriptionOwner
 import org.jetbrains.kotlin.fir.declarations.FirMemberFunction
 import org.jetbrains.kotlin.fir.declarations.FirSimpleFunction
 import org.jetbrains.kotlin.fir.declarations.FirPropertyAccessor
@@ -113,6 +114,7 @@ import org.jetbrains.kotlin.fir.types.FirDynamicTypeRef
 import org.jetbrains.kotlin.fir.types.FirFunctionTypeRef
 import org.jetbrains.kotlin.fir.types.FirResolvedFunctionTypeRef
 import org.jetbrains.kotlin.fir.types.FirImplicitTypeRef
+import org.jetbrains.kotlin.fir.contracts.FirContractDescription
 
 /*
  * This file was generated automatically
@@ -258,6 +260,10 @@ abstract class FirVisitorVoid : FirVisitor<Unit, Nothing?>() {
         visitElement(function)
     }
 
+    open fun visitContractDescriptionOwner(contractDescriptionOwner: FirContractDescriptionOwner) {
+        visitElement(contractDescriptionOwner)
+    }
+
     open fun <F : FirMemberFunction<F>> visitMemberFunction(memberFunction: FirMemberFunction<F>) {
         visitElement(memberFunction)
     }
@@ -550,6 +556,10 @@ abstract class FirVisitorVoid : FirVisitor<Unit, Nothing?>() {
         visitElement(implicitTypeRef)
     }
 
+    open fun visitContractDescription(contractDescription: FirContractDescription) {
+        visitElement(contractDescription)
+    }
+
     final override fun visitElement(element: FirElement, data: Nothing?) {
         visitElement(element)
     }
@@ -690,6 +700,10 @@ abstract class FirVisitorVoid : FirVisitor<Unit, Nothing?>() {
         visitFunction(function)
     }
 
+    final override fun visitContractDescriptionOwner(contractDescriptionOwner: FirContractDescriptionOwner, data: Nothing?) {
+        visitContractDescriptionOwner(contractDescriptionOwner)
+    }
+
     final override fun <F : FirMemberFunction<F>> visitMemberFunction(memberFunction: FirMemberFunction<F>, data: Nothing?) {
         visitMemberFunction(memberFunction)
     }
@@ -982,4 +996,8 @@ abstract class FirVisitorVoid : FirVisitor<Unit, Nothing?>() {
         visitImplicitTypeRef(implicitTypeRef)
     }
 
+    final override fun visitContractDescription(contractDescription: FirContractDescription, data: Nothing?) {
+        visitContractDescription(contractDescription)
+    }
+
 }

compiler/fir/tree/tree-generator/src/org/jetbrains/kotlin/fir/tree/generator/FirTreeBuilder.kt

@@ -49,9 +49,10 @@ object FirTreeBuilder : AbstractFirTreeBuilder() {
 
     val function = element("Function", Declaration, callableDeclaration, controlFlowGraphOwner, targetElement, annotationContainer, typeParametersOwner, statement)
 
+    val contractDescriptionOwner = element("ContractDescriptionOwner", Declaration)
     val memberFunction = element("MemberFunction", Declaration, function, callableMemberDeclaration)
-    val simpleFunction = element("SimpleFunction", Declaration, memberFunction)
-    val propertyAccessor = element("PropertyAccessor", Declaration, function)
+    val simpleFunction = element("SimpleFunction", Declaration, memberFunction, contractDescriptionOwner)
+    val propertyAccessor = element("PropertyAccessor", Declaration, function, contractDescriptionOwner)
     val constructor = element("Constructor", Declaration, memberFunction)
     val file = element("File", Declaration, annotationContainer, declaration)
 
@@ -132,4 +133,6 @@ object FirTreeBuilder : AbstractFirTreeBuilder() {
     val functionTypeRef = element("FunctionTypeRef", TypeRef, typeRefWithNullability)
     val resolvedFunctionTypeRef = element("ResolvedFunctionTypeRef", TypeRef, resolvedTypeRef, functionTypeRef)
     val implicitTypeRef = element("ImplicitTypeRef", TypeRef, typeRef)
-}
+
+    val contractDescription = element("ContractDescription", Contracts)
+}

compiler/fir/tree/tree-generator/src/org/jetbrains/kotlin/fir/tree/generator/ImplementationConfigurator.kt

@@ -402,7 +402,8 @@ object ImplementationConfigurator : AbstractFirTreeImplementationConfigurator()
                 withGetter = true
             }
             defaultNull("body")
-            useTypes(modalityType)
+            default("contractDescription", "FirEmptyContractDescription")
+            useTypes(modalityType, emptyContractDescriptionType)
             kind = OpenClass
         }
 
@@ -556,6 +557,8 @@ object ImplementationConfigurator : AbstractFirTreeImplementationConfigurator()
             parents += modifiableFunction.withArg(simpleFunction)
             parents += modifiableTypeParametersOwner
             defaultNull("body")
+            default("contractDescription", "FirEmptyContractDescription")
+            useTypes(emptyContractDescriptionType)
         }
 
         impl(delegatedTypeRef) {

compiler/fir/tree/tree-generator/src/org/jetbrains/kotlin/fir/tree/generator/NodeConfigurator.kt

@@ -266,6 +266,10 @@ object NodeConfigurator : AbstractFieldConfigurator() {
             parentArg(memberFunction, "F", simpleFunction)
         }
 
+        contractDescriptionOwner.configure {
+            +field(contractDescription).withTransform()
+        }
+
         property.configure {
             parentArg(variable, "F", property)
             parentArg(callableMemberDeclaration, "F", property)
@@ -524,6 +528,10 @@ object NodeConfigurator : AbstractFieldConfigurator() {
         errorNamedReference.configure {
             +stringField("errorReason")
         }
+
+        contractDescription.configure {
+            +fieldList("effects", effectDeclarationType)
+        }
     }
 }
 

compiler/fir/tree/tree-generator/src/org/jetbrains/kotlin/fir/tree/generator/Types.kt

@@ -61,4 +61,6 @@ val backingFieldSymbolType = type("fir.symbols.impl", "FirBackingFieldSymbol")
 val delegateFieldSymbolType = type("fir.symbols.impl", "FirDelegateFieldSymbol")
 val classSymbolType = type("fir.symbols.impl", "FirClassSymbol")
 
-val pureAbstractElementType = generatedType("FirPureAbstractElement")
+val pureAbstractElementType = generatedType("FirPureAbstractElement")
+val effectDeclarationType = type("fir.contracts.description", "ConeEffectDeclaration")
+val emptyContractDescriptionType = generatedType("contracts.impl", "FirEmptyContractDescription")

compiler/fir/tree/tree-generator/src/org/jetbrains/kotlin/fir/tree/generator/model/Element.kt

@@ -124,6 +124,7 @@ class Element(val name: String, kind: Kind) : AbstractElement {
         Declaration("declarations"),
         Reference("references"),
         TypeRef("types"),
+        Contracts("contracts"),
         Other("")
     }
 }