[NI] Extract logic about fixation order to separated component

compiler/resolution/src/org/jetbrains/kotlin/resolve/calls/KotlinResolutionConfiguration.kt

@@ -19,3 +19,9 @@ package org.jetbrains.kotlin.resolve.calls
 val USE_NEW_INFERENCE = false
 
 val REPORT_MISSING_NEW_INFERENCE_DIAGNOSTIC = false
+
+val USE_CS_COMPLETER_TYPE = CSCompleterType.INITIAL
+
+enum class CSCompleterType {
+    INITIAL
+}

compiler/resolution/src/org/jetbrains/kotlin/resolve/calls/components/ConstraintSystemCompleter.kt

@@ -0,0 +1,53 @@
+/*
+ * Copyright 2010-2017 JetBrains s.r.o.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package org.jetbrains.kotlin.resolve.calls.components
+
+import org.jetbrains.kotlin.resolve.calls.inference.components.FixationOrderCalculator
+import org.jetbrains.kotlin.resolve.calls.inference.components.ResultTypeResolver
+import org.jetbrains.kotlin.resolve.calls.inference.model.NewTypeVariable
+import org.jetbrains.kotlin.resolve.calls.model.KotlinCallDiagnostic
+import org.jetbrains.kotlin.resolve.calls.model.PostponedKotlinCallArgument
+import org.jetbrains.kotlin.types.UnwrappedType
+
+interface ConstraintSystemCompleter {
+    enum class CompletionType {
+        FULL,
+        PARTIAL
+    }
+
+    interface Context {
+        val hasContradiction: Boolean
+        val postponedArguments: List<PostponedKotlinCallArgument>
+
+        // type can be proper if it not contains not fixed type variables
+        fun canBeProper(type: UnwrappedType): Boolean
+        fun asFixationOrderCalculatorContext(): FixationOrderCalculator.Context
+        fun asResultTypeResolverContext(): ResultTypeResolver.Context
+
+        // mutable operations
+        fun addError(error: KotlinCallDiagnostic)
+        fun fixVariable(variable: NewTypeVariable, resultType: UnwrappedType)
+    }
+
+    fun runCompletion(
+            c: Context,
+            type: CompletionType,
+            topLevelType: UnwrappedType,
+            analyze: (PostponedKotlinCallArgument) -> Unit
+    )
+
+}

compiler/resolution/src/org/jetbrains/kotlin/resolve/calls/components/InitialConstraintSystemCompleterImpl.kt

@@ -0,0 +1,79 @@
+/*
+ * Copyright 2010-2017 JetBrains s.r.o.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package org.jetbrains.kotlin.resolve.calls.components
+
+import org.jetbrains.kotlin.resolve.calls.components.ConstraintSystemCompleter.Context
+import org.jetbrains.kotlin.resolve.calls.inference.components.FixationOrderCalculator
+import org.jetbrains.kotlin.resolve.calls.inference.components.InferenceStepResolver
+import org.jetbrains.kotlin.resolve.calls.model.PostponedCallableReferenceArgument
+import org.jetbrains.kotlin.resolve.calls.model.PostponedKotlinCallArgument
+import org.jetbrains.kotlin.resolve.calls.model.PostponedLambdaArgument
+import org.jetbrains.kotlin.types.UnwrappedType
+
+class InitialConstraintSystemCompleterImpl(
+        private val fixationOrderCalculator: FixationOrderCalculator,
+        private val inferenceStepResolver: InferenceStepResolver
+) : ConstraintSystemCompleter {
+
+    override fun runCompletion(
+            c: Context,
+            type: ConstraintSystemCompleter.CompletionType,
+            topLevelType: UnwrappedType,
+            analyze: (PostponedKotlinCallArgument) -> Unit
+    ) {
+        if (type == ConstraintSystemCompleter.CompletionType.PARTIAL) return
+
+        resolveCallableReferenceArguments(c, analyze)
+
+        while (!oneStepToEndOrLambda(c, topLevelType, analyze)) {
+            // do nothing -- be happy
+        }
+    }
+
+    private fun resolveCallableReferenceArguments(c: Context, analyze: (PostponedKotlinCallArgument) -> Unit) {
+        c.postponedArguments.filterIsInstance<PostponedCallableReferenceArgument>().forEach(analyze)
+    }
+
+    // true if it is the end (happy or not)
+    // every step we fix type variable or analyzeLambda
+    private fun oneStepToEndOrLambda(
+            c: Context,
+            topLevelType: UnwrappedType,
+            analyze: (PostponedKotlinCallArgument) -> Unit
+    ): Boolean {
+        val lambda = c.postponedArguments.find { it is PostponedLambdaArgument && canWeAnalyzeIt(c, it) }
+        if (lambda != null) {
+            analyze(lambda)
+            return false
+        }
+
+        val completionOrder = fixationOrderCalculator.computeCompletionOrder(c.asFixationOrderCalculatorContext(), topLevelType)
+        return inferenceStepResolver.resolveVariables(c, completionOrder)
+    }
+
+
+    private fun canWeAnalyzeIt(c: Context, lambda: PostponedLambdaArgument): Boolean {
+        if (lambda.analyzed) return false
+
+        if (c.hasContradiction) return true
+
+        lambda.receiver?.let {
+            if (!c.canBeProper(it)) return false
+        }
+        return lambda.parameters.all { c.canBeProper(it) }
+    }
+}

compiler/resolution/src/org/jetbrains/kotlin/resolve/calls/components/KotlinCallCompleter.kt

@@ -19,11 +19,11 @@ package org.jetbrains.kotlin.resolve.calls.components
 import org.jetbrains.kotlin.descriptors.CallableDescriptor
 import org.jetbrains.kotlin.descriptors.FunctionDescriptor
 import org.jetbrains.kotlin.descriptors.PropertyDescriptor
-import org.jetbrains.kotlin.resolve.calls.inference.ConstraintSystemBuilder
+import org.jetbrains.kotlin.resolve.calls.CSCompleterType
-import org.jetbrains.kotlin.resolve.calls.inference.components.*
+import org.jetbrains.kotlin.resolve.calls.USE_CS_COMPLETER_TYPE
+import org.jetbrains.kotlin.resolve.calls.components.ConstraintSystemCompleter.CompletionType
+import org.jetbrains.kotlin.resolve.calls.inference.components.NewTypeSubstitutor
 import org.jetbrains.kotlin.resolve.calls.inference.model.ExpectedTypeConstraintPosition
-import org.jetbrains.kotlin.resolve.calls.inference.model.LambdaArgumentConstraintPosition
-import org.jetbrains.kotlin.resolve.calls.inference.model.NewTypeVariable
 import org.jetbrains.kotlin.resolve.calls.inference.returnTypeOrNothing
 import org.jetbrains.kotlin.resolve.calls.inference.substituteAndApproximateCapturedTypes
 import org.jetbrains.kotlin.resolve.calls.model.*
@@ -32,33 +32,22 @@ import org.jetbrains.kotlin.types.TypeApproximatorConfiguration
 import org.jetbrains.kotlin.types.TypeUtils
 import org.jetbrains.kotlin.types.UnwrappedType
 import org.jetbrains.kotlin.types.checker.NewCapturedType
-import org.jetbrains.kotlin.types.typeUtil.builtIns
 import org.jetbrains.kotlin.types.typeUtil.contains
 
 class KotlinCallCompleter(
-        private val fixationOrderCalculator: FixationOrderCalculator,
         private val additionalDiagnosticReporter: AdditionalDiagnosticReporter,
-        private val inferenceStepResolver: InferenceStepResolver,
+        private val postponedArgumentsAnalyzer: PostponedArgumentsAnalyzer,
-        private val callableReferenceResolver: CallableReferenceResolver
+        initialConstraintSystemCompleter: InitialConstraintSystemCompleterImpl
 ) {
+    private val constraintSystemCompleter: ConstraintSystemCompleter = when(USE_CS_COMPLETER_TYPE) {
+        CSCompleterType.INITIAL -> initialConstraintSystemCompleter
+    }
+
     interface Context {
         val innerCalls: List<ResolvedKotlinCall.OnlyResolvedKotlinCall>
-        val hasContradiction: Boolean
-        fun buildCurrentSubstitutor(): NewTypeSubstitutor
         fun buildResultingSubstitutor(): NewTypeSubstitutor
         val postponedArguments: List<PostponedKotlinCallArgument>
         val lambdaArguments: List<PostponedLambdaArgument>
-
-        // type can be proper if it not contains not fixed type variables
-        fun canBeProper(type: UnwrappedType): Boolean
-        fun asFixationOrderCalculatorContext(): FixationOrderCalculator.Context
-        fun asResultTypeResolverContext(): ResultTypeResolver.Context
-
-        // mutable operations
-        fun asConstraintInjectorContext(): ConstraintInjector.Context
-        fun addError(error: KotlinCallDiagnostic)
-        fun fixVariable(variable: NewTypeVariable, resultType: UnwrappedType)
-        fun getBuilder(): ConstraintSystemBuilder
     }
 
     fun transformWhenAmbiguity(candidate: KotlinResolutionCandidate, resolutionCallbacks: KotlinResolutionCallbacks): ResolvedKotlinCall =
@@ -77,22 +66,18 @@ class KotlinCallCompleter(
                     else -> candidate as SimpleKotlinResolutionCandidate
                 }
 
-        if (topLevelCall.prepareForCompletion(expectedType)) {
+        val completionType = topLevelCall.prepareForCompletion(expectedType)
-            val c = candidate.lastCall.constraintSystem.asCallCompleterContext()
+        val constraintSystem = candidate.lastCall.constraintSystem
 
-            resolveCallableReferenceArguments(c)
+        constraintSystemCompleter.runCompletion(
-
+                constraintSystem.asConstraintSystemCompleterContext(), completionType, candidate.lastCall.descriptorWithFreshTypes.returnTypeOrNothing
-            topLevelCall.competeCall(c, resolutionCallbacks)
+        ) {
-            return toCompletedBaseResolvedCall(c, candidate, resolutionCallbacks)
+            postponedArgumentsAnalyzer.analyze(constraintSystem.asPostponedArgumentsAnalyzerContext(), resolutionCallbacks, it)
         }
 
-        return ResolvedKotlinCall.OnlyResolvedKotlinCall(candidate)
+        return when (completionType) {
-    }
+            CompletionType.FULL -> toCompletedBaseResolvedCall(constraintSystem.asCallCompleterContext(), candidate, resolutionCallbacks)
-
+            CompletionType.PARTIAL -> ResolvedKotlinCall.OnlyResolvedKotlinCall(candidate)
-    private fun resolveCallableReferenceArguments(c: Context) {
-        for (callableReferenceArgument in c.postponedArguments) {
-            if (callableReferenceArgument !is PostponedCallableReferenceArgument) continue
-            callableReferenceResolver.processCallableReferenceArgument(c.getBuilder(), callableReferenceArgument)
         }
     }
 
@@ -169,62 +154,17 @@ class KotlinCallCompleter(
     }
 
     // true if we should complete this call
-    private fun SimpleKotlinResolutionCandidate.prepareForCompletion(expectedType: UnwrappedType?): Boolean {
+    private fun SimpleKotlinResolutionCandidate.prepareForCompletion(expectedType: UnwrappedType?): CompletionType {
-        val returnType = descriptorWithFreshTypes.returnType?.unwrap() ?: return false
+        val returnType = descriptorWithFreshTypes.returnType?.unwrap() ?: return CompletionType.PARTIAL
         if (expectedType != null && !TypeUtils.noExpectedType(expectedType)) {
             csBuilder.addSubtypeConstraint(returnType, expectedType, ExpectedTypeConstraintPosition(kotlinCall))
         }
 
-        return expectedType != null || csBuilder.isProperType(returnType)
+        return if (expectedType != null || csBuilder.isProperType(returnType)) {
-    }
+            CompletionType.FULL
-
-    private fun SimpleKotlinResolutionCandidate.competeCall(c: Context, resolutionCallbacks: KotlinResolutionCallbacks) {
-        while (!oneStepToEndOrLambda(c, resolutionCallbacks)) {
-            // do nothing -- be happy
         }
-    }
+        else {
-
+            CompletionType.PARTIAL
-    // true if it is the end (happy or not)
-    // every step we fix type variable or analyzeLambda
-    private fun SimpleKotlinResolutionCandidate.oneStepToEndOrLambda(c: Context, resolutionCallbacks: KotlinResolutionCallbacks): Boolean {
-        val lambda = c.lambdaArguments.find { canWeAnalyzeIt(c, it) }
-        if (lambda != null) {
-            analyzeLambda(c, resolutionCallbacks, lambda)
-            return false
         }
-
-        val completionOrder = fixationOrderCalculator.computeCompletionOrder(c.asFixationOrderCalculatorContext(), descriptorWithFreshTypes.returnTypeOrNothing)
-        return inferenceStepResolver.resolveVariables(c, completionOrder)
-    }
-
-    private fun analyzeLambda(c: Context, resolutionCallbacks: KotlinResolutionCallbacks, lambda: PostponedLambdaArgument) {
-        val currentSubstitutor = c.buildCurrentSubstitutor()
-        fun substitute(type: UnwrappedType) = currentSubstitutor.safeSubstitute(type)
-
-        val receiver = lambda.receiver?.let(::substitute)
-        val parameters = lambda.parameters.map(::substitute)
-        val expectedType = lambda.returnType.takeIf { c.canBeProper(it) }?.let(::substitute)
-        lambda.analyzed = true
-        lambda.resultArguments = resolutionCallbacks.analyzeAndGetLambdaResultArguments(lambda.argument, lambda.isSuspend, receiver, parameters, expectedType)
-
-        for (resultLambdaArgument in lambda.resultArguments) {
-            checkSimpleArgument(c.getBuilder(), resultLambdaArgument, lambda.returnType.let(::substitute))
-        }
-
-        if (lambda.resultArguments.isEmpty()) {
-            val unitType = lambda.returnType.builtIns.unitType
-            c.getBuilder().addSubtypeConstraint(lambda.returnType.let(::substitute), unitType, LambdaArgumentConstraintPosition(lambda))
-        }
-    }
-
-    private fun canWeAnalyzeIt(c: Context, lambda: PostponedLambdaArgument): Boolean {
-        if (lambda.analyzed) return false
-
-        if (c.hasContradiction) return true // to record info about lambda and avoid exceptions
-
-        lambda.receiver?.let {
-            if (!c.canBeProper(it)) return false
-        }
-        return lambda.parameters.all { c.canBeProper(it) }
     }
 }

compiler/resolution/src/org/jetbrains/kotlin/resolve/calls/components/PostponedArgumentsAnalyzer.kt

@@ -0,0 +1,69 @@
+/*
+ * Copyright 2010-2017 JetBrains s.r.o.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package org.jetbrains.kotlin.resolve.calls.components
+
+import org.jetbrains.kotlin.resolve.calls.inference.ConstraintSystemBuilder
+import org.jetbrains.kotlin.resolve.calls.inference.components.NewTypeSubstitutor
+import org.jetbrains.kotlin.resolve.calls.inference.model.LambdaArgumentConstraintPosition
+import org.jetbrains.kotlin.resolve.calls.model.PostponedCallableReferenceArgument
+import org.jetbrains.kotlin.resolve.calls.model.PostponedCollectionLiteralArgument
+import org.jetbrains.kotlin.resolve.calls.model.PostponedKotlinCallArgument
+import org.jetbrains.kotlin.resolve.calls.model.PostponedLambdaArgument
+import org.jetbrains.kotlin.types.UnwrappedType
+import org.jetbrains.kotlin.types.typeUtil.builtIns
+
+class PostponedArgumentsAnalyzer(
+        private val callableReferenceResolver: CallableReferenceResolver
+) {
+    interface Context {
+        fun buildCurrentSubstitutor(): NewTypeSubstitutor
+
+        // type can be proper if it not contains not fixed type variables
+        fun canBeProper(type: UnwrappedType): Boolean
+
+        // mutable operations
+        fun getBuilder(): ConstraintSystemBuilder
+    }
+
+    fun analyze(c: Context, resolutionCallbacks: KotlinResolutionCallbacks, argument: PostponedKotlinCallArgument) {
+        when (argument) {
+            is PostponedLambdaArgument -> analyzeLambda(c, resolutionCallbacks, argument)
+            is PostponedCallableReferenceArgument -> callableReferenceResolver.processCallableReferenceArgument(c.getBuilder(), argument)
+            is PostponedCollectionLiteralArgument -> TODO("Not supported")
+        }
+    }
+
+    private fun analyzeLambda(c: Context, resolutionCallbacks: KotlinResolutionCallbacks, lambda: PostponedLambdaArgument) {
+        val currentSubstitutor = c.buildCurrentSubstitutor()
+        fun substitute(type: UnwrappedType) = currentSubstitutor.safeSubstitute(type)
+
+        val receiver = lambda.receiver?.let(::substitute)
+        val parameters = lambda.parameters.map(::substitute)
+        val expectedType = lambda.returnType.takeIf { c.canBeProper(it) }?.let(::substitute)
+        lambda.analyzed = true
+        lambda.resultArguments = resolutionCallbacks.analyzeAndGetLambdaResultArguments(lambda.argument, lambda.isSuspend, receiver, parameters, expectedType)
+
+        for (resultLambdaArgument in lambda.resultArguments) {
+            checkSimpleArgument(c.getBuilder(), resultLambdaArgument, lambda.returnType.let(::substitute))
+        }
+
+        if (lambda.resultArguments.isEmpty()) {
+            val unitType = lambda.returnType.builtIns.unitType
+            c.getBuilder().addSubtypeConstraint(lambda.returnType.let(::substitute), unitType, LambdaArgumentConstraintPosition(lambda))
+        }
+    }
+}

compiler/resolution/src/org/jetbrains/kotlin/resolve/calls/inference/NewConstraintSystem.kt

@@ -16,7 +16,9 @@
 
 package org.jetbrains.kotlin.resolve.calls.inference
 
+import org.jetbrains.kotlin.resolve.calls.components.ConstraintSystemCompleter
 import org.jetbrains.kotlin.resolve.calls.components.KotlinCallCompleter
+import org.jetbrains.kotlin.resolve.calls.components.PostponedArgumentsAnalyzer
 import org.jetbrains.kotlin.resolve.calls.inference.model.ConstraintStorage
 import org.jetbrains.kotlin.resolve.calls.model.KotlinCallDiagnostic
 
@@ -28,4 +30,6 @@ interface NewConstraintSystem {
     // after this method we shouldn't mutate system via ConstraintSystemBuilder
     fun asReadOnlyStorage(): ConstraintStorage
     fun asCallCompleterContext(): KotlinCallCompleter.Context
+    fun asConstraintSystemCompleterContext(): ConstraintSystemCompleter.Context
+    fun asPostponedArgumentsAnalyzerContext(): PostponedArgumentsAnalyzer.Context
 }

compiler/resolution/src/org/jetbrains/kotlin/resolve/calls/inference/components/InferenceStepResolver.kt

@@ -17,7 +17,7 @@
 package org.jetbrains.kotlin.resolve.calls.inference.components
 
 import org.jetbrains.kotlin.builtins.KotlinBuiltIns
-import org.jetbrains.kotlin.resolve.calls.components.KotlinCallCompleter
+import org.jetbrains.kotlin.resolve.calls.components.ConstraintSystemCompleter
 import org.jetbrains.kotlin.resolve.calls.inference.model.Constraint
 import org.jetbrains.kotlin.resolve.calls.inference.model.ConstraintKind
 import org.jetbrains.kotlin.resolve.calls.inference.model.NotEnoughInformationForTypeParameter
@@ -32,7 +32,7 @@ class InferenceStepResolver(
      * Resolves one or more of the `variables`.
      * Returns `true` if type variable resolution should stop.
      */
-    fun resolveVariables(c: KotlinCallCompleter.Context, variables: List<VariableResolutionNode>): Boolean {
+    fun resolveVariables(c: ConstraintSystemCompleter.Context, variables: List<VariableResolutionNode>): Boolean {
         if (variables.isEmpty()) return true
         if (c.hasContradiction) return true
 
@@ -50,7 +50,7 @@ class InferenceStepResolver(
         return false
     }
 
-    private fun VariableWithConstraints.hasProperConstraint(c: KotlinCallCompleter.Context) =
+    private fun VariableWithConstraints.hasProperConstraint(c: ConstraintSystemCompleter.Context) =
             constraints.any { !it.isTrivial() && c.canBeProper(it.type) }
 
     private fun Constraint.isTrivial() =

compiler/resolution/src/org/jetbrains/kotlin/resolve/calls/inference/model/NewConstraintSystemImpl.kt

@@ -16,7 +16,9 @@
 
 package org.jetbrains.kotlin.resolve.calls.inference.model
 
+import org.jetbrains.kotlin.resolve.calls.components.ConstraintSystemCompleter
 import org.jetbrains.kotlin.resolve.calls.components.KotlinCallCompleter
+import org.jetbrains.kotlin.resolve.calls.components.PostponedArgumentsAnalyzer
 import org.jetbrains.kotlin.resolve.calls.inference.*
 import org.jetbrains.kotlin.resolve.calls.inference.components.*
 import org.jetbrains.kotlin.resolve.calls.model.*
@@ -34,7 +36,9 @@ class NewConstraintSystemImpl(val constraintInjector: ConstraintInjector, val re
         ConstraintInjector.Context,
         ResultTypeResolver.Context,
         KotlinCallCompleter.Context,
-        FixationOrderCalculator.Context
+        FixationOrderCalculator.Context,
+        ConstraintSystemCompleter.Context,
+        PostponedArgumentsAnalyzer.Context
 {
     private val storage = MutableConstraintStorage()
     private var state = State.BUILDING
@@ -58,8 +62,6 @@ class NewConstraintSystemImpl(val constraintInjector: ConstraintInjector, val re
 
     override fun getBuilder() = apply { checkState(State.BUILDING, State.COMPLETION) }
 
-    override fun asConstraintInjectorContext() = apply { checkState(State.BUILDING, State.COMPLETION) }
-
     override fun asReadOnlyStorage(): ConstraintStorage {
         checkState(State.BUILDING, State.FREEZED)
         state = State.FREEZED
@@ -72,6 +74,10 @@ class NewConstraintSystemImpl(val constraintInjector: ConstraintInjector, val re
         return this
     }
 
+    override fun asConstraintSystemCompleterContext() = apply { checkState(State.BUILDING) }
+
+    override fun asPostponedArgumentsAnalyzerContext() = apply { checkState(State.BUILDING) }
+
     // ConstraintSystemOperation
     override fun registerVariable(variable: NewTypeVariable) {
         checkState(State.BUILDING, State.COMPLETION, State.TRANSACTION)
@@ -178,10 +184,11 @@ class NewConstraintSystemImpl(val constraintInjector: ConstraintInjector, val re
         return storage.buildCurrentSubstitutor()
     }
 
-    // ConstraintSystemBuilder, KotlinCallCompleter.Context
+    // ConstraintSystemBuilder, ConstraintSystemCompleter.Context
     override val hasContradiction: Boolean
         get() = diagnostics.any { !it.candidateApplicability.isSuccess }.apply { checkState(State.BUILDING, State.COMPLETION, State.TRANSACTION) }
 
+    // ConstraintSystemBuilder
     override fun addInnerCall(innerCall: ResolvedKotlinCall.OnlyResolvedKotlinCall) {
         checkState(State.BUILDING, State.COMPLETION)
         storage.innerCalls.add(innerCall)
@@ -232,7 +239,7 @@ class NewConstraintSystemImpl(val constraintInjector: ConstraintInjector, val re
         return storage.notFixedTypeVariables
     }
 
-    // ConstraintInjector.Context, KotlinCallCompleter.Context
+    // ConstraintInjector.Context, ConstraintSystemCompleter.Context
     override fun addError(error: KotlinCallDiagnostic) {
         checkState(State.BUILDING, State.COMPLETION, State.TRANSACTION)
         storage.errors.add(error)
@@ -240,18 +247,18 @@ class NewConstraintSystemImpl(val constraintInjector: ConstraintInjector, val re
 
     //  KotlinCallCompleter.Context, FixationOrderCalculator.Context
     override val lambdaArguments: List<PostponedLambdaArgument> get() {
-        checkState(State.COMPLETION)
+        checkState(State.BUILDING, State.COMPLETION)
         return storage.postponedArguments.filterIsInstance<PostponedLambdaArgument>()
     }
 
-    // FixationOrderCalculator.Context
+    // FixationOrderCalculator.Context, KotlinCallCompleter.Context, ConstraintSystemCompleter.Context
     override val postponedArguments: List<PostponedKotlinCallArgument>
-        get() = storage.postponedArguments
+        get() = storage.postponedArguments.apply { checkState(State.BUILDING, State.COMPLETION) }
 
-    // KotlinCallCompleter.Context
+    // ConstraintSystemCompleter.Context
-    override fun asResultTypeResolverContext() = apply { checkState(State.COMPLETION) }
+    override fun asResultTypeResolverContext() = apply { checkState(State.BUILDING, State.COMPLETION) }
 
-    override fun asFixationOrderCalculatorContext() = apply { checkState(State.COMPLETION) }
+    override fun asFixationOrderCalculatorContext() = apply { checkState(State.BUILDING, State.COMPLETION) }
 
     override fun fixVariable(variable: NewTypeVariable, resultType: UnwrappedType) {
         checkState(State.BUILDING, State.COMPLETION)
@@ -268,21 +275,25 @@ class NewConstraintSystemImpl(val constraintInjector: ConstraintInjector, val re
         storage.fixedTypeVariables[variable.freshTypeConstructor] = resultType
     }
 
+    // KotlinCallCompleter.Context
     override val innerCalls: List<ResolvedKotlinCall.OnlyResolvedKotlinCall> get() {
         checkState(State.COMPLETION)
         return storage.innerCalls
     }
 
+    // ConstraintSystemCompleter.Context, PostponedArgumentsAnalyzer.Context
     override fun canBeProper(type: UnwrappedType): Boolean {
-        checkState(State.COMPLETION)
+        checkState(State.BUILDING, State.COMPLETION)
         return !type.contains { storage.notFixedTypeVariables.containsKey(it.constructor) }
     }
 
+    // PostponedArgumentsAnalyzer.Context
     override fun buildCurrentSubstitutor(): NewTypeSubstitutor {
-        checkState(State.COMPLETION)
+        checkState(State.BUILDING, State.COMPLETION)
         return storage.buildCurrentSubstitutor()
     }
 
+    // KotlinCallCompleter.Context
     override fun buildResultingSubstitutor(): NewTypeSubstitutor {
         checkState(State.COMPLETION)
         val currentSubstitutorMap = storage.fixedTypeVariables.entries.associate {