[NI] Fix recursion in contract declaration analysis.

#KT-30410 Fixed

compiler/frontend/src/org/jetbrains/kotlin/resolve/RecursiveContractHelper.kt

@@ -0,0 +1,37 @@
+/*
+ * 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.resolve
+
+import org.jetbrains.kotlin.contracts.description.ContractProviderKey
+import org.jetbrains.kotlin.contracts.description.LazyContractProvider
+import org.jetbrains.kotlin.contracts.parsing.isContractCallDescriptor
+import org.jetbrains.kotlin.descriptors.CallableDescriptor
+import org.jetbrains.kotlin.descriptors.FunctionDescriptor
+import org.jetbrains.kotlin.psi.Call
+import org.jetbrains.kotlin.psi.KtExpression
+import org.jetbrains.kotlin.psi.psiUtil.isContractDescriptionCallPsiCheck
+import org.jetbrains.kotlin.psi.psiUtil.isFirstStatement
+import org.jetbrains.kotlin.resolve.scopes.LexicalScope
+import org.jetbrains.kotlin.utils.addToStdlib.safeAs
+
+/*
+ * See KT-26386 and KT-30410
+ */
+fun disableContractsInsideContractsBlock(call: Call, descriptor: CallableDescriptor?, scope: LexicalScope, trace: BindingTrace) {
+    call.callElement.safeAs<KtExpression>()?.let { callExpression ->
+        if (callExpression.isFirstStatement() && callExpression.isContractDescriptionCallPsiCheck()) {
+            if (descriptor?.isContractCallDescriptor() != true) {
+                scope.ownerDescriptor
+                    .safeAs<FunctionDescriptor>()
+                    ?.getUserData(ContractProviderKey)
+                    ?.safeAs<LazyContractProvider>()
+                    ?.setContractDescription(null)
+            } else {
+                trace.record(BindingContext.IS_CONTRACT_DECLARATION_BLOCK, callExpression, true)
+            }
+        }
+    }
+}

compiler/frontend/src/org/jetbrains/kotlin/resolve/calls/CallCompleter.kt

@@ -135,19 +135,7 @@ class CallCompleter(
         context: BasicCallResolutionContext,
         tracing: TracingStrategy
     ) {
-        context.call.callElement.safeAs<KtExpression>()?.let { callExpression ->
-            if (callExpression.isFirstStatement() && callExpression.isContractDescriptionCallPsiCheck()) {
-                if (resolvedCall?.resultingDescriptor?.isContractCallDescriptor() != true) {
-                    context.scope.ownerDescriptor
-                        .safeAs<FunctionDescriptor>()
-                        ?.getUserData(ContractProviderKey)
-                        ?.safeAs<LazyContractProvider>()
-                        ?.setContractDescription(null)
-                } else {
-                    context.trace.record(BindingContext.IS_CONTRACT_DECLARATION_BLOCK, callExpression, true)
-                }
-            }
-        }
+        disableContractsInsideContractsBlock(context.call, resolvedCall?.resultingDescriptor, context.scope, context.trace)
 
         if (resolvedCall == null || resolvedCall.isCompleted || resolvedCall.constraintSystem == null) {
             completeArguments(context, results)

compiler/frontend/src/org/jetbrains/kotlin/resolve/calls/tower/KotlinResolutionCallbacksImpl.kt

@@ -265,4 +265,10 @@ class KotlinResolutionCallbacksImpl(
         trace.record(BindingContext.CAST_TYPE_USED_AS_EXPECTED_TYPE, binaryParent)
         return resultType
     }
+
+    override fun disableContractsIfNecessary(resolvedAtom: ResolvedCallAtom) {
+        val atom = resolvedAtom.atom as? PSIKotlinCall ?: return
+        val context = topLevelCallContext ?: return
+        disableContractsInsideContractsBlock(atom.psiCall, resolvedAtom.candidateDescriptor, context.scope, trace)
+    }
 }

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

@@ -55,6 +55,8 @@ interface KotlinResolutionCallbacks {
     val inferenceSession: InferenceSession
 
     fun getExpectedTypeFromAsExpressionAndRecordItInTrace(resolvedAtom: ResolvedCallAtom): UnwrappedType?
+
+    fun disableContractsIfNecessary(resolvedAtom: ResolvedCallAtom)
 }
 
 interface SamConversionTransformer {

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

@@ -133,7 +133,10 @@ class KotlinCallCompleter(
         val candidate = candidates.singleOrNull()
 
         // this is needed at least for non-local return checker, because when we analyze lambda we should already bind descriptor for outer call
-        candidate?.resolvedCall?.let { resolutionCallbacks.bindStubResolvedCallForCandidate(it) }
+        candidate?.resolvedCall?.let {
+            resolutionCallbacks.bindStubResolvedCallForCandidate(it)
+            resolutionCallbacks.disableContractsIfNecessary(it)
+        }
 
         return candidate ?: factory.createErrorCandidate().forceResolution()
     }