[NI] Update lambda result types.

When completing calls, update return types for functional descriptors
for lambdas using type inference results.

Add toString to some Call subclasses (for debugging purposes).

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

@@ -43,7 +43,6 @@ import org.jetbrains.kotlin.resolve.constants.evaluate.ConstantExpressionEvaluat
 import org.jetbrains.kotlin.resolve.scopes.receivers.ReceiverValue
 import org.jetbrains.kotlin.types.KotlinType
 import org.jetbrains.kotlin.types.TypeUtils
-import org.jetbrains.kotlin.types.UnwrappedType
 import org.jetbrains.kotlin.types.expressions.DataFlowAnalyzer
 import java.util.*
 import kotlin.collections.HashMap

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

@@ -21,20 +21,20 @@ import org.jetbrains.kotlin.builtins.getReturnTypeFromFunctionType
 import org.jetbrains.kotlin.builtins.isFunctionType
 import org.jetbrains.kotlin.descriptors.CallableDescriptor
 import org.jetbrains.kotlin.descriptors.annotations.Annotations
+import org.jetbrains.kotlin.descriptors.impl.FunctionDescriptorImpl
 import org.jetbrains.kotlin.psi.KtExpression
 import org.jetbrains.kotlin.psi.KtPsiUtil
 import org.jetbrains.kotlin.psi.psiUtil.lastBlockStatementOrThis
+import org.jetbrains.kotlin.resolve.BindingContext
 import org.jetbrains.kotlin.resolve.BindingTrace
 import org.jetbrains.kotlin.resolve.calls.components.LambdaAnalyzer
 import org.jetbrains.kotlin.types.TypeApproximator
 import org.jetbrains.kotlin.types.TypeApproximatorConfiguration
 import org.jetbrains.kotlin.resolve.calls.context.ContextDependency
-import org.jetbrains.kotlin.resolve.calls.model.KotlinCall
+import org.jetbrains.kotlin.resolve.calls.model.*
-import org.jetbrains.kotlin.resolve.calls.model.KotlinCallArgument
-import org.jetbrains.kotlin.resolve.calls.model.KotlinResolutionCandidate
-import org.jetbrains.kotlin.resolve.calls.model.LambdaKotlinCallArgument
 import org.jetbrains.kotlin.resolve.calls.util.CallMaker
 import org.jetbrains.kotlin.resolve.descriptorUtil.builtIns
+import org.jetbrains.kotlin.types.KotlinType
 import org.jetbrains.kotlin.types.TypeUtils
 import org.jetbrains.kotlin.types.UnwrappedType
 import org.jetbrains.kotlin.types.expressions.ExpressionTypingServices
@@ -94,4 +94,16 @@ class LambdaAnalyzerImpl(
     override fun bindStubResolvedCallForCandidate(candidate: KotlinResolutionCandidate) {
         kotlinToResolvedCallTransformer.createStubResolvedCallAndWriteItToTrace<CallableDescriptor>(candidate, trace)
     }
+
+    override fun completeLambdaReturnType(lambdaArgument: ResolvedLambdaArgument, returnType: KotlinType) {
+        val psiCallArgument = lambdaArgument.argument.psiCallArgument
+        val ktFunction = when (psiCallArgument) {
+            is LambdaKotlinCallArgumentImpl -> psiCallArgument.ktLambdaExpression.functionLiteral
+            is FunctionExpressionImpl -> psiCallArgument.ktFunction
+            else -> throw AssertionError("Unexpected psiCallArgument for resolved lambda argument: $psiCallArgument")
+        }
+        val functionDescriptor = trace.bindingContext.get(BindingContext.FUNCTION, ktFunction) as? FunctionDescriptorImpl ?:
+                                 throw AssertionError("No function descriptor for resolved lambda argument")
+        functionDescriptor.setReturnType(returnType)
+    }
 }

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

@@ -130,7 +130,9 @@ class PSICallResolver(
         val expectedType = context.expectedType.unwrap()
 
         return if (context.contextDependency == ContextDependency.DEPENDENT) {
-            assert(expectedType == TypeUtils.NO_EXPECTED_TYPE)
+            assert(TypeUtils.noExpectedType(expectedType)) {
+                "Should have no expected type, got: $expectedType"
+            }
             null
         }
         else {

compiler/frontend/src/org/jetbrains/kotlin/resolve/calls/util/CallMaker.java

@@ -366,6 +366,11 @@ public class CallMaker {
             public CallType getCallType() {
                 return CallType.DEFAULT;
             }
+
+            @Override
+            public String toString() {
+                return DebugTextUtilKt.getDebugText(callElement);
+            }
         };
     }
 

compiler/frontend/src/org/jetbrains/kotlin/resolve/calls/util/DelegatingCall.java

@@ -100,4 +100,9 @@ public class DelegatingCall implements Call {
     public CallType getCallType() {
         return delegate.getCallType();
     }
+
+    @Override
+    public String toString() {
+        return "*" + delegate.toString();
+    }
 }

compiler/frontend/src/org/jetbrains/kotlin/types/expressions/FunctionsTypingVisitor.kt

@@ -220,8 +220,10 @@ internal class FunctionsTypingVisitor(facade: ExpressionTypingInternals) : Expre
 
         // This is needed for ControlStructureTypingVisitor#visitReturnExpression() to properly type-check returned expressions
         context.trace.record(EXPECTED_RETURN_TYPE, functionLiteral, expectedType)
-        val typeOfBodyExpression = // Type-check the body
+
-                components.expressionTypingServices.getBlockReturnedType(functionLiteral.bodyExpression!!, COERCION_TO_UNIT, newContext).type
+        // Type-check the body
+        val blockReturnedType = components.expressionTypingServices.getBlockReturnedType(functionLiteral.bodyExpression!!, COERCION_TO_UNIT, newContext)
+        val typeOfBodyExpression = blockReturnedType.type
 
         return computeReturnTypeBasedOnReturnExpressions(functionLiteral, context, typeOfBodyExpression)
     }

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

@@ -102,7 +102,7 @@ class KotlinCallResolver(
         }
 
         return maximallySpecificCandidates.map {
-            kotlinCallCompleter.transformWhenAmbiguity(it)
+            kotlinCallCompleter.transformWhenAmbiguity(it, callContext.lambdaAnalyzer)
         }
     }
 }

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

@@ -17,10 +17,8 @@
 package org.jetbrains.kotlin.resolve.calls.components
 
 import org.jetbrains.kotlin.descriptors.CallableDescriptor
-import org.jetbrains.kotlin.resolve.calls.model.KotlinCall
+import org.jetbrains.kotlin.resolve.calls.model.*
-import org.jetbrains.kotlin.resolve.calls.model.KotlinCallArgument
+import org.jetbrains.kotlin.types.KotlinType
-import org.jetbrains.kotlin.resolve.calls.model.KotlinResolutionCandidate
-import org.jetbrains.kotlin.resolve.calls.model.LambdaKotlinCallArgument
 import org.jetbrains.kotlin.types.UnwrappedType
 
 interface IsDescriptorFromSourcePredicate: (CallableDescriptor) -> Boolean
@@ -39,4 +37,6 @@ interface LambdaAnalyzer {
     // todo this is hack for some client which try to read ResolvedCall from trace before all calls completed
     fun bindStubResolvedCallForCandidate(candidate: KotlinResolutionCandidate)
 
+    fun completeLambdaReturnType(lambdaArgument: ResolvedLambdaArgument, returnType: KotlinType)
+
 }

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

@@ -63,8 +63,8 @@ class KotlinCallCompleter(
         fun getBuilder(): ConstraintSystemBuilder
     }
 
-    fun transformWhenAmbiguity(candidate: KotlinResolutionCandidate): ResolvedKotlinCall =
+    fun transformWhenAmbiguity(candidate: KotlinResolutionCandidate, lambdaAnalyzer: LambdaAnalyzer): ResolvedKotlinCall =
-            toCompletedBaseResolvedCall(candidate.lastCall.constraintSystem.asCallCompleterContext(), candidate)
+            toCompletedBaseResolvedCall(candidate.lastCall.constraintSystem.asCallCompleterContext(), candidate, lambdaAnalyzer)
 
     fun completeCallIfNecessary(
             candidate: KotlinResolutionCandidate,
@@ -82,7 +82,7 @@ class KotlinCallCompleter(
             val c = candidate.lastCall.constraintSystem.asCallCompleterContext()
 
             topLevelCall.competeCall(c, lambdaAnalyzer)
-            return toCompletedBaseResolvedCall(c, candidate)
+            return toCompletedBaseResolvedCall(c, candidate, lambdaAnalyzer)
         }
 
         return ResolvedKotlinCall.OnlyResolvedKotlinCall(candidate)
@@ -90,13 +90,17 @@ class KotlinCallCompleter(
 
     private fun toCompletedBaseResolvedCall(
             c: Context,
-            candidate: KotlinResolutionCandidate
+            candidate: KotlinResolutionCandidate,
+            lambdaAnalyzer: LambdaAnalyzer
     ): ResolvedKotlinCall.CompletedResolvedKotlinCall {
         val currentSubstitutor = c.buildResultingSubstitutor()
         val completedCall = candidate.toCompletedCall(currentSubstitutor)
         val competedCalls = c.innerCalls.map {
             it.candidate.toCompletedCall(currentSubstitutor)
         }
+        c.lambdaArguments.forEach {
+            lambdaAnalyzer.completeLambdaReturnType(it, currentSubstitutor.safeSubstitute(it.returnType))
+        }
         return ResolvedKotlinCall.CompletedResolvedKotlinCall(completedCall, competedCalls)
     }