Get rid of FUNCTOR slice, use lazy value in ContractDecription instead

Functor is an imperative representation of function's contract (contrary
to ContractDescription, which is a declarative one). ContractDescription
is convenient when we deal with sources of contracts declarations
(binaries, source), while Functors are convenient for analyzing code
with contracts.

It means that we have to convert ContractDescription into Functor when
we start working with contracts. This computation isn't trivial, and
Functor and ContractDescription are in 1-1 correspondence, so we would
like to cache Functor for each ContractDescription somewhere.

We used to do this in binding trace, in slice FUNCTOR.

Now, it turns out that this approach causes "Rewrite at slice"
exception, see KT-28847. We won't go into details of why that happens
here, you can see the issue comments for details (but be prepared for the
very long and nitty-gritty story)

This commit removes the problematic slice and introduces another
approach, where Functor is attached to the ContractDescription, computed
lazily and cached here.

^KT-28847 Fixed

compiler/frontend/src/org/jetbrains/kotlin/contracts/ContractDeserializerImpl.kt

@@ -28,10 +28,14 @@ import org.jetbrains.kotlin.metadata.deserialization.isInstanceType
 import org.jetbrains.kotlin.serialization.deserialization.ContractDeserializer
 import org.jetbrains.kotlin.serialization.deserialization.DeserializationConfiguration
 import org.jetbrains.kotlin.serialization.deserialization.TypeDeserializer
+import org.jetbrains.kotlin.storage.StorageManager
 import org.jetbrains.kotlin.types.KotlinType
 import org.jetbrains.kotlin.utils.addIfNotNull
 
-class ContractDeserializerImpl(private val configuration: DeserializationConfiguration) : ContractDeserializer {
+class ContractDeserializerImpl(
+    private val configuration: DeserializationConfiguration,
+    private val storageManager: StorageManager
+) : ContractDeserializer {
     override fun deserializeContractFromFunction(
         proto: ProtoBuf.Function,
         ownerFunction: FunctionDescriptor,
@@ -42,7 +46,7 @@ class ContractDeserializerImpl(private val configuration: DeserializationConfigu
 
         if (!configuration.readDeserializedContracts) return null
 
-        val worker = ContractDeserializationWorker(typeTable, typeDeserializer, ownerFunction)
+        val worker = ContractDeserializationWorker(typeTable, typeDeserializer, ownerFunction, storageManager)
         val contract = worker.deserializeContract(proto.contract)
         return ContractProviderKey to LazyContractProvider.createInitialized(contract)
     }
@@ -50,12 +54,13 @@ class ContractDeserializerImpl(private val configuration: DeserializationConfigu
     private class ContractDeserializationWorker(
         private val typeTable: TypeTable,
         private val typeDeserializer: TypeDeserializer,
-        private val ownerFunction: FunctionDescriptor
+        private val ownerFunction: FunctionDescriptor,
+        private val storageManager: StorageManager
     ) {
 
         fun deserializeContract(proto: ProtoBuf.Contract): ContractDescription? {
             val effects = proto.effectList.map { deserializePossiblyConditionalEffect(it) ?: return null }
-            return ContractDescription(effects, ownerFunction)
+            return ContractDescription(effects, ownerFunction, storageManager)
         }
 
         private fun deserializePossiblyConditionalEffect(proto: ProtoBuf.Effect): EffectDeclaration? {
@@ -75,7 +80,7 @@ class ContractDeserializerImpl(private val configuration: DeserializationConfigu
                     val argument = proto.effectConstructorArgumentList.getOrNull(0)
                     val returnValue =
                         if (argument == null) ConstantReference.WILDCARD else deserializeExpression(argument) as? ConstantReference
-                                ?: return null
+                            ?: return null
                     ReturnsEffectDeclaration(returnValue)
                 }
 

compiler/frontend/src/org/jetbrains/kotlin/contracts/EffectsExtractingVisitor.kt

@@ -17,6 +17,7 @@
 package org.jetbrains.kotlin.contracts
 
 import org.jetbrains.kotlin.builtins.DefaultBuiltIns
+import org.jetbrains.kotlin.contracts.description.ContractProviderKey
 import org.jetbrains.kotlin.contracts.interpretation.ContractInterpretationDispatcher
 import org.jetbrains.kotlin.contracts.model.Computation
 import org.jetbrains.kotlin.contracts.model.ConditionalEffect
@@ -168,11 +169,8 @@ class EffectsExtractingVisitor(
     }
 
     private fun FunctionDescriptor.getFunctor(): Functor? {
-        trace[BindingContext.FUNCTOR, this]?.let { return it }
+        val contractDescription = getUserData(ContractProviderKey)?.getContractDescription() ?: return null
-
+        return contractDescription.functor
-        val functor = ContractInterpretationDispatcher().resolveFunctor(this) ?: return null
-        trace.record(BindingContext.FUNCTOR, this, functor)
-        return functor
     }
 
     private fun ResolvedCall<*>.isCallWithUnsupportedReceiver(): Boolean =

compiler/frontend/src/org/jetbrains/kotlin/contracts/parsing/ContractParsingServices.kt

@@ -32,8 +32,9 @@ import org.jetbrains.kotlin.resolve.BindingTrace
 import org.jetbrains.kotlin.resolve.calls.callUtil.getResolvedCall
 import org.jetbrains.kotlin.resolve.scopes.LexicalScope
 import org.jetbrains.kotlin.resolve.scopes.LexicalScopeKind
+import org.jetbrains.kotlin.storage.StorageManager
 
-class ContractParsingServices(val languageVersionSettings: LanguageVersionSettings) {
+class ContractParsingServices(val languageVersionSettings: LanguageVersionSettings, private val storageManager: StorageManager) {
     /**
      * ! IMPORTANT NOTICE !
      *
@@ -77,7 +78,7 @@ class ContractParsingServices(val languageVersionSettings: LanguageVersionSettin
             // Small optimization: do not even try to parse contract if we already have errors
             if (collector.hasErrors()) return null
 
-            val parsedContract = PsiContractParserDispatcher(collector, callContext).parseContract()
+            val parsedContract = PsiContractParserDispatcher(collector, callContext, storageManager).parseContract()
 
             // Make sure that at least generic error will be reported if we couldn't parse contract
             // (null returned => at least one error was reported)

compiler/frontend/src/org/jetbrains/kotlin/contracts/parsing/PsiContractParserDispatcher.kt

@@ -40,10 +40,12 @@ import org.jetbrains.kotlin.psi.KtExpression
 import org.jetbrains.kotlin.psi.KtLambdaExpression
 import org.jetbrains.kotlin.resolve.calls.callUtil.getResolvedCall
 import org.jetbrains.kotlin.resolve.calls.callUtil.getType
+import org.jetbrains.kotlin.storage.StorageManager
 
 internal class PsiContractParserDispatcher(
     private val collector: ContractParsingDiagnosticsCollector,
-    private val callContext: ContractCallContext
+    private val callContext: ContractCallContext,
+    private val storageManager: StorageManager
 ) {
     private val conditionParser = PsiConditionParser(collector, callContext, this)
     private val constantParser = PsiConstantParser(callContext)
@@ -71,7 +73,7 @@ internal class PsiContractParserDispatcher(
 
         if (effects.isEmpty()) return null
 
-        return ContractDescription(effects, callContext.functionDescriptor)
+        return ContractDescription(effects, callContext.functionDescriptor, storageManager)
     }
 
     fun parseCondition(expression: KtExpression?): BooleanExpression? = expression?.accept(conditionParser, Unit)

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

@@ -98,7 +98,6 @@ public interface BindingContext {
     WritableSlice<KtExpression, DataFlowInfo> DATA_FLOW_INFO_BEFORE = new BasicWritableSlice<>(DO_NOTHING);
     WritableSlice<KtExpression, KotlinType> EXPECTED_EXPRESSION_TYPE = new BasicWritableSlice<>(DO_NOTHING);
     WritableSlice<KtElement, Computation> EXPRESSION_EFFECTS = Slices.createSimpleSlice();
-    WritableSlice<FunctionDescriptor, Functor> FUNCTOR = Slices.createSimpleSlice();
     WritableSlice<KtFunction, KotlinType> EXPECTED_RETURN_TYPE = new BasicWritableSlice<>(DO_NOTHING);
     WritableSlice<KtExpression, DataFlowInfo> DATAFLOW_INFO_AFTER_CONDITION = Slices.createSimpleSlice();
     WritableSlice<VariableDescriptor, DataFlowValue> BOUND_INITIALIZER_VALUE = Slices.createSimpleSlice();

compiler/resolution/src/org/jetbrains/kotlin/contracts/description/ContractDescription.kt

@@ -16,7 +16,10 @@
 
 package org.jetbrains.kotlin.contracts.description
 
+import org.jetbrains.kotlin.contracts.interpretation.ContractInterpretationDispatcher
+import org.jetbrains.kotlin.contracts.model.Functor
 import org.jetbrains.kotlin.descriptors.FunctionDescriptor
+import org.jetbrains.kotlin.storage.StorageManager
 
 /**
  * This is actual model of contracts, i.e. what is expected to be parsed from
@@ -30,7 +33,18 @@ import org.jetbrains.kotlin.descriptors.FunctionDescriptor
  * backward compatibility. Ideally, this model should only be extended, but not
  * changed.
  */
-open class ContractDescription(val effects: List<EffectDeclaration>, val ownerFunction: FunctionDescriptor)
+open class ContractDescription(
+    val effects: List<EffectDeclaration>,
+    val ownerFunction: FunctionDescriptor,
+    storageManager: StorageManager
+) {
+    private val functorLazyValue = storageManager.createNullableLazyValue {
+        ContractInterpretationDispatcher().convertContractDescriptorToFunctor(this)
+    }
+
+    val functor: Functor?
+        get() = functorLazyValue()
+}
 
 interface ContractDescriptionElement {
     fun <R, D> accept(contractDescriptionVisitor: ContractDescriptionVisitor<R, D>, data: D): R

compiler/resolution/src/org/jetbrains/kotlin/contracts/interpretation/ContractInterpretationDispatcher.kt

@@ -39,12 +39,7 @@ class ContractInterpretationDispatcher {
         CallsEffectInterpreter(this)
     )
 
-    fun resolveFunctor(functionDescriptor: FunctionDescriptor): Functor? {
+    fun convertContractDescriptorToFunctor(contractDescription: ContractDescription): Functor? {
-        val contractDescriptor = functionDescriptor.getUserData(ContractProviderKey)?.getContractDescription() ?: return null
-        return convertContractDescriptorToFunctor(contractDescriptor)
-    }
-
-    private fun convertContractDescriptorToFunctor(contractDescription: ContractDescription): Functor? {
         val resultingClauses = contractDescription.effects.map { effect ->
             if (effect is ConditionalEffectDeclaration) {
                 conditionalEffectInterpreter.interpret(effect) ?: return null

compiler/testData/diagnostics/testsWithStdLib/contracts/dsl/rewriteAtSliceFunctor.txt

@@ -1,10 +1,10 @@
 package
 
 public final class Foo {
-    public constructor Foo()
+    public constructor Foo(/*0*/ str: kotlin.String?)
-    private final val foo: Foo.foo.<no name provided>
+    public final val first: kotlin.Boolean
-    public final var property: kotlin.String?
+    public final val second: kotlin.Boolean
-    public final inline fun </*0*/ T> equalVetoingObservable(/*0*/ initialValue: T, /*1*/ crossinline onChange: (newValue: T) -> kotlin.Unit): kotlin.properties.ObservableProperty<T>
+    public final val str: kotlin.String?
     public open override /*1*/ /*fake_override*/ fun equals(/*0*/ other: kotlin.Any?): kotlin.Boolean
     public open override /*1*/ /*fake_override*/ fun hashCode(): kotlin.Int
     public open override /*1*/ /*fake_override*/ fun toString(): kotlin.String

idea/idea-analysis/src/org/jetbrains/kotlin/idea/decompiler/classFile/DeserializerForClassfileDecompiler.kt

@@ -77,7 +77,7 @@ class DeserializerForClassfileDecompiler(
                 storageManager, moduleDescriptor, configuration, classDataFinder, annotationAndConstantLoader,
                 packageFragmentProvider, ResolveEverythingToKotlinAnyLocalClassifierResolver(builtIns), LoggingErrorReporter(LOG),
                 LookupTracker.DO_NOTHING, JavaFlexibleTypeDeserializer, emptyList(), notFoundClasses,
-                ContractDeserializerImpl(configuration),
+                ContractDeserializerImpl(configuration, storageManager),
                 extensionRegistryLite = JvmProtoBufUtil.EXTENSION_REGISTRY
         )
     }

js/js.serializer/src/org/jetbrains/kotlin/serialization/js/kotlinJavascriptPackageFragmentProvider.kt

@@ -76,7 +76,7 @@ fun createKotlinJavascriptPackageFragmentProvider(
         DynamicTypeDeserializer,
         emptyList(),
         notFoundClasses,
-        ContractDeserializerImpl(configuration),
+        ContractDeserializerImpl(configuration, storageManager),
         platformDependentDeclarationFilter = PlatformDependentDeclarationFilter.NoPlatformDependent,
         extensionRegistryLite = JsSerializerProtocol.extensionRegistry
     )

konan/library-reader/src/org/jetbrains/kotlin/serialization/konan/impl/KonanDeserializedPackageFragmentsFactoryImpl.kt

@@ -119,7 +119,7 @@ internal object KonanDeserializedPackageFragmentsFactoryImpl : KonanDeserialized
             NullFlexibleTypeDeserializer,
             emptyList(),
             notFoundClasses,
-            ContractDeserializerImpl(configuration),
+            ContractDeserializerImpl(configuration, storageManager),
             extensionRegistryLite = KonanSerializerProtocol.extensionRegistry
         )