FIR CFA: skip member function graphs when looking for member assignments

Shouldn't affect the result, since in member functions all properties
are assumed to be initialized so the CFG is not needed for reporting
VAL_REASSIGNMENT.

compiler/fir/checkers/src/org/jetbrains/kotlin/fir/analysis/cfa/util/CfgTraverser.kt

@@ -14,17 +14,12 @@ enum class TraverseDirection {
 fun <I : ControlFlowInfo<I, *, *>> ControlFlowGraph.collectDataForNode(
     direction: TraverseDirection,
     visitor: PathAwareControlFlowGraphVisitor<I>,
-    visitSubGraphs: Boolean = true
 ): Map<CFGNode<*>, PathAwareControlFlowInfo<I>> {
-    val nodeMap = LinkedHashMap<CFGNode<*>, PathAwareControlFlowInfo<I>>()
-    val startNode = getEnterNode(direction)
-    nodeMap[startNode] = visitor.emptyInfo
-
+    val nodeMap = HashMap<CFGNode<*>, PathAwareControlFlowInfo<I>>()
     var shouldContinue: Boolean
     do {
-        shouldContinue = collectDataForNodeInternal(direction, visitor, nodeMap, visitSubGraphs)
+        shouldContinue = collectDataForNodeInternal(direction, visitor, nodeMap)
     } while (shouldContinue)
-
     return nodeMap
 }
 
@@ -32,38 +27,36 @@ private fun <I : ControlFlowInfo<I, *, *>> ControlFlowGraph.collectDataForNodeIn
     direction: TraverseDirection,
     visitor: PathAwareControlFlowGraphVisitor<I>,
     nodeMap: MutableMap<CFGNode<*>, PathAwareControlFlowInfo<I>>,
-    visitSubGraphs: Boolean = true
 ): Boolean {
     var changed = false
-    val nodes = getNodesInOrder(direction)
-    for (node in nodes) {
-        if (visitSubGraphs && direction == TraverseDirection.Backward && node is CFGNodeWithSubgraphs<*>) {
-            node.subGraphs.forEach { changed = changed or it.collectDataForNodeInternal(direction, visitor, nodeMap) }
-        }
-        val previousNodes = when (direction) {
-            TraverseDirection.Forward -> node.previousCfgNodes
-            TraverseDirection.Backward -> node.followingCfgNodes
+    for (node in getNodesInOrder(direction)) {
+        if (direction == TraverseDirection.Backward && node is CFGNodeWithSubgraphs<*>) {
+            node.subGraphs.forEach {
+                changed = changed or (visitor.visitSubGraph(node, it) && it.collectDataForNodeInternal(direction, visitor, nodeMap))
+            }
         }
         // TODO: if data for previousNodes hasn't changed, then should be no need to recompute data for this one
         val union = node.isUnion
-        val previousData =
-            previousNodes.mapNotNull {
-                val k = when (direction) {
-                    TraverseDirection.Forward -> node.edgeFrom(it)
-                    TraverseDirection.Backward -> node.edgeTo(it)
+        val previousData = when (direction) {
+            TraverseDirection.Forward -> node.previousCfgNodes
+            TraverseDirection.Backward -> node.followingCfgNodes
+        }.mapNotNull { source ->
+            nodeMap[source]?.let {
+                val edge = when (direction) {
+                    TraverseDirection.Forward -> node.edgeFrom(source)
+                    TraverseDirection.Backward -> node.edgeTo(source)
                 }
-                val v = nodeMap[it] ?: return@mapNotNull null
-                visitor.visitEdge(it, node, k, v)
-            }.reduceOrNull { a, b -> a.join(b, union) }
-        val data = nodeMap[node]
+                visitor.visitEdge(source, node, edge, it)
+            }
+        }.reduceOrNull { a, b -> a.join(b, union) }
         val newData = node.accept(visitor, previousData ?: visitor.emptyInfo)
-        val hasChanged = newData != data
-        changed = changed or hasChanged
-        if (hasChanged) {
-            nodeMap[node] = newData
+        if (newData != nodeMap.put(node, newData)) {
+            changed = true
         }
-        if (visitSubGraphs && direction == TraverseDirection.Forward && node is CFGNodeWithSubgraphs<*>) {
-            node.subGraphs.forEach { changed = changed or it.collectDataForNodeInternal(direction, visitor, nodeMap) }
+        if (direction == TraverseDirection.Forward && node is CFGNodeWithSubgraphs<*>) {
+            node.subGraphs.forEach {
+                changed = changed or (visitor.visitSubGraph(node, it) && it.collectDataForNodeInternal(direction, visitor, nodeMap))
+            }
         }
     }
     return changed

compiler/fir/checkers/src/org/jetbrains/kotlin/fir/analysis/cfa/util/CfgUtils.kt

@@ -8,11 +8,6 @@ package org.jetbrains.kotlin.fir.analysis.cfa.util
 import org.jetbrains.kotlin.fir.resolve.dfa.cfg.CFGNode
 import org.jetbrains.kotlin.fir.resolve.dfa.cfg.ControlFlowGraph
 
-fun ControlFlowGraph.getEnterNode(direction: TraverseDirection): CFGNode<*> = when (direction) {
-    TraverseDirection.Forward -> enterNode
-    TraverseDirection.Backward -> exitNode
-}
-
 fun ControlFlowGraph.getNodesInOrder(direction: TraverseDirection): List<CFGNode<*>> = when (direction) {
     TraverseDirection.Forward -> nodes
     TraverseDirection.Backward -> nodes.asReversed()

compiler/fir/checkers/src/org/jetbrains/kotlin/fir/analysis/cfa/util/PathAwareControlFlowGraphVisitor.kt

@@ -31,6 +31,9 @@ abstract class PathAwareControlFlowGraphVisitor<I : ControlFlowInfo<I, *, *>> :
 
     abstract val emptyInfo: PathAwareControlFlowInfo<I>
 
+    open fun visitSubGraph(node: CFGNodeWithSubgraphs<*>, graph: ControlFlowGraph): Boolean =
+        true // false to skip
+
     open fun visitEdge(from: CFGNode<*>, to: CFGNode<*>, metadata: Edge, data: PathAwareControlFlowInfo<I>): PathAwareControlFlowInfo<I> {
         val label = metadata.label
         return when {

compiler/fir/checkers/src/org/jetbrains/kotlin/fir/analysis/cfa/util/PropertyInitializationInfoCollector.kt

@@ -39,6 +39,11 @@ class PropertyInitializationInfoCollector(
     override val emptyInfo: PathAwarePropertyInitializationInfo
         get() = EMPTY_INFO
 
+    // When looking for initializations of member properties, skip subgraphs of member functions;
+    // all properties are assumed to be initialized there.
+    override fun visitSubGraph(node: CFGNodeWithSubgraphs<*>, graph: ControlFlowGraph): Boolean =
+        expectedReceiver == null || node !is ClassExitNode || node !== node.owner.exitNode
+
     override fun visitVariableAssignmentNode(
         node: VariableAssignmentNode,
         data: PathAwarePropertyInitializationInfo

compiler/fir/checkers/src/org/jetbrains/kotlin/fir/analysis/checkers/declaration/FirMemberPropertiesChecker.kt

@@ -50,7 +50,6 @@ object FirMemberPropertiesChecker : FirClassChecker() {
             (it.symbol as? FirPropertySymbol)?.takeIf { symbol -> symbol.requiresInitialization }
         }
         if (memberPropertySymbols.isEmpty()) return null
-        // TODO: this also visits non-constructor member functions...
         // TODO: merge with `FirPropertyInitializationAnalyzer` for fewer passes.
         val data = PropertyInitializationInfoData(memberPropertySymbols, symbol, graph)
         data.checkPropertyAccesses(context, reporter)