FIR IDE: get unstable smartcast from FE1.0-based analysis API

Note that the current FE1.0 implementation still has some limitations

1. only references used as receiver are being considered for smartcast.
2. Somehow the smartcast information is not retained if the for generic
typed receivers. See multiSmartcastAsReceiver_stable.descriptors.txt

analysis/analysis-api-fe10/src/org/jetbrains/kotlin/analysis/api/descriptors/components/KtFe10SmartCastProvider.kt

@@ -28,13 +28,17 @@ internal class KtFe10SmartCastProvider(override val analysisSession: KtFe10Analy
         withValidityAssertion {
             val bindingContext = analysisSession.analyze(expression)
             val stableSmartCasts = bindingContext[BindingContext.SMARTCAST, expression]
+            val unstableSmartCasts = bindingContext[BindingContext.UNSTABLE_SMARTCAST, expression]
 
             return when {
                 stableSmartCasts != null -> {
                     val type = stableSmartCasts.getKtType() ?: return null
                     SmartCastInfo(type, true)
                 }
-                // TODO: collect unstable smartcast here.
+                unstableSmartCasts != null -> {
+                    val type = unstableSmartCasts.getKtType() ?: return null
+                    SmartCastInfo(type, false)
+                }
                 else -> null
             }
         }

analysis/analysis-api/testData/components/smartCastInfo/multiSmartcastAsReceiver_unstable.descriptors.txt

@@ -1,3 +1,3 @@
 expression: a
-isStable: null
-smartCastType: null
+isStable: false
+smartCastType: (A & B)

analysis/analysis-api/testData/components/smartCastInfo/smartcastAsReceiver_unstable.txt

@@ -1,3 +1,3 @@
 expression: a
-isStable: null
-smartCastType: null
+isStable: false
+smartCastType: kotlin.String

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

@@ -157,6 +157,7 @@ public interface BindingContext {
     WritableSlice<KtCollectionLiteralExpression, ResolvedCall<FunctionDescriptor>> COLLECTION_LITERAL_CALL = Slices.createSimpleSlice();
 
     WritableSlice<KtExpression, ExplicitSmartCasts> SMARTCAST = new BasicWritableSlice<>(DO_NOTHING);
+    WritableSlice<KtExpression, ExplicitSmartCasts> UNSTABLE_SMARTCAST = new BasicWritableSlice<>(DO_NOTHING);
     WritableSlice<KtExpression, Boolean> SMARTCAST_NULL = Slices.createSimpleSlice();
     WritableSlice<KtExpression, ImplicitSmartCasts> IMPLICIT_RECEIVER_SMARTCAST = new BasicWritableSlice<>(DO_NOTHING);
 

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

@@ -16,16 +16,19 @@ import org.jetbrains.kotlin.psi.*
 import org.jetbrains.kotlin.psi.psiUtil.isNull
 import org.jetbrains.kotlin.psi.psiUtil.lastBlockStatementOrThis
 import org.jetbrains.kotlin.resolve.BindingContext
-import org.jetbrains.kotlin.resolve.calls.util.*
 import org.jetbrains.kotlin.resolve.calls.context.BasicCallResolutionContext
 import org.jetbrains.kotlin.resolve.calls.inference.BuilderInferenceExpectedTypeConstraintPosition
 import org.jetbrains.kotlin.resolve.calls.inference.model.*
 import org.jetbrains.kotlin.resolve.calls.model.*
 import org.jetbrains.kotlin.resolve.calls.smartcasts.DataFlowValueFactory
+import org.jetbrains.kotlin.resolve.calls.smartcasts.SingleSmartCast
 import org.jetbrains.kotlin.resolve.calls.smartcasts.SmartCastManager
 import org.jetbrains.kotlin.resolve.calls.tasks.TracingStrategy
 import org.jetbrains.kotlin.resolve.calls.tower.*
-import org.jetbrains.kotlin.resolve.calls.util.*
+import org.jetbrains.kotlin.resolve.calls.util.extractCallableReferenceExpression
+import org.jetbrains.kotlin.resolve.calls.util.getCalleeExpressionIfAny
+import org.jetbrains.kotlin.resolve.calls.util.getResolvedCall
+import org.jetbrains.kotlin.resolve.calls.util.reportTrailingLambdaErrorOr
 import org.jetbrains.kotlin.resolve.constants.CompileTimeConstantChecker
 import org.jetbrains.kotlin.resolve.constants.TypedCompileTimeConstant
 import org.jetbrains.kotlin.resolve.constants.evaluate.ConstantExpressionEvaluator
@@ -358,10 +361,12 @@ class DiagnosticReporterByTrackingStrategy(
         val argumentExpression = unstableSmartCast.argument.psiExpression ?: return
 
         require(possibleTypes.isNotEmpty()) { "Receiver for unstable smart cast without possible types" }
+        val intersectWrappedTypes = intersectWrappedTypes(possibleTypes)
+        trace.record(BindingContext.UNSTABLE_SMARTCAST, argumentExpression, SingleSmartCast(null, intersectWrappedTypes))
         trace.report(
             SMARTCAST_IMPOSSIBLE.on(
                 argumentExpression,
-                intersectWrappedTypes(possibleTypes),
+                intersectWrappedTypes,
                 argumentExpression.text,
                 dataFlowValue.kind.description
             )

compiler/frontend/src/org/jetbrains/kotlin/resolve/calls/smartcasts/SmartCastManager.kt

@@ -25,8 +25,7 @@ import org.jetbrains.kotlin.diagnostics.Errors.SMARTCAST_IMPOSSIBLE
 import org.jetbrains.kotlin.psi.Call
 import org.jetbrains.kotlin.psi.KtExpression
 import org.jetbrains.kotlin.resolve.BindingContext
-import org.jetbrains.kotlin.resolve.BindingContext.IMPLICIT_RECEIVER_SMARTCAST
-import org.jetbrains.kotlin.resolve.BindingContext.SMARTCAST
+import org.jetbrains.kotlin.resolve.BindingContext.*
 import org.jetbrains.kotlin.resolve.BindingTrace
 import org.jetbrains.kotlin.resolve.calls.ArgumentTypeResolver
 import org.jetbrains.kotlin.resolve.calls.context.ResolutionContext
@@ -37,8 +36,8 @@ import org.jetbrains.kotlin.types.KotlinType
 import org.jetbrains.kotlin.types.TypeUtils
 import org.jetbrains.kotlin.types.checker.intersectWrappedTypes
 import org.jetbrains.kotlin.types.typeUtil.expandIntersectionTypeIfNecessary
+import org.jetbrains.kotlin.util.slicedMap.WritableSlice
 import org.jetbrains.kotlin.utils.addIfNotNull
-import java.util.*
 
 class SmartCastManager(private val argumentTypeResolver: ArgumentTypeResolver) {
 
@@ -232,23 +231,35 @@ class SmartCastManager(private val argumentTypeResolver: ArgumentTypeResolver) {
                     trace.report(Errors.DEPRECATED_SMARTCAST.on(expression, type, expression.text, dataFlowValue.kind.description))
                 }
 
-                val oldSmartCasts = trace[SMARTCAST, expression]
-                val newSmartCast = SingleSmartCast(call, type)
-                if (oldSmartCasts != null) {
-                    val oldType = oldSmartCasts.type(call)
-                    if (oldType != null && oldType != type) {
-                        throw AssertionError("Rewriting key $call for smart cast on ${expression.text}")
-                    }
-                }
-                trace.record(SMARTCAST, expression, oldSmartCasts?.let { it + newSmartCast } ?: newSmartCast)
+                updateSmartCast(trace, expression, call, type, SMARTCAST)
                 if (recordExpressionType) {
                     //TODO
                     //Why the expression type is rewritten for receivers and is not rewritten for arguments? Is it necessary?
                     trace.recordType(expression, type)
                 }
             } else {
+                updateSmartCast(trace, expression, call, type, UNSTABLE_SMARTCAST)
                 trace.report(SMARTCAST_IMPOSSIBLE.on(expression, type, expression.text, dataFlowValue.kind.description))
             }
         }
+
+        private fun updateSmartCast(
+            trace: BindingTrace,
+            expression: KtExpression,
+            call: Call?,
+            type: KotlinType,
+            key: WritableSlice<KtExpression, ExplicitSmartCasts>?
+        ) {
+            val oldSmartCasts = trace[key, expression]
+            val newSmartCast = SingleSmartCast(call, type)
+            if (oldSmartCasts != null) {
+                val oldType = oldSmartCasts.type(call)
+                if (oldType != null && oldType != type) {
+                    throw AssertionError("Rewriting key $call for smart cast on ${expression.text}")
+                }
+            }
+            val updatedSmartCasts = oldSmartCasts?.let { it + newSmartCast } ?: newSmartCast
+            trace.record(key, expression, updatedSmartCasts)
+        }
     }
 }