From 1e04945609a37a175ea86954da14555f780d8679 Mon Sep 17 00:00:00 2001
From: Mikhail Glukhikh <Mikhail.Glukhikh@jetbrains.com>
Date: Thu, 20 Oct 2016 16:08:21 +0300
Subject: [PATCH] CFG refactoring: get rid of mergeWithLocalDeclarations
 (always true) + minor style fixes

---
 .../kotlin/cfg/PseudocodeTraverser.kt         | 31 +++++++------------
 .../cfg/PseudocodeVariableDataCollector.kt    |  3 +-
 .../kotlin/cfg/PseudocodeVariablesData.kt     |  8 ++---
 3 files changed, 14 insertions(+), 28 deletions(-)

diff --git a/compiler/frontend/src/org/jetbrains/kotlin/cfg/PseudocodeTraverser.kt b/compiler/frontend/src/org/jetbrains/kotlin/cfg/PseudocodeTraverser.kt
index 50176e5efea..7fbd205157f 100644
--- a/compiler/frontend/src/org/jetbrains/kotlin/cfg/PseudocodeTraverser.kt
+++ b/compiler/frontend/src/org/jetbrains/kotlin/cfg/PseudocodeTraverser.kt
@@ -57,7 +57,6 @@ fun <D> Pseudocode.traverse(
 
 fun <I : ControlFlowInfo<*>> Pseudocode.collectData(
         traversalOrder: TraversalOrder,
-        mergeDataWithLocalDeclarations: Boolean,
         mergeEdges: (Instruction, Collection<I>) -> Edges<I>,
         updateEdge: (Instruction, Instruction, I) -> I,
         initialInfo: I
@@ -70,7 +69,7 @@ fun <I : ControlFlowInfo<*>> Pseudocode.collectData(
     while (changed[0]) {
         changed[0] = false
         collectDataFromSubgraph(
-                traversalOrder, mergeDataWithLocalDeclarations, edgesMap,
+                traversalOrder, edgesMap,
                 mergeEdges, updateEdge, Collections.emptyList<Instruction>(), changed, false)
     }
     return edgesMap
@@ -78,7 +77,6 @@ fun <I : ControlFlowInfo<*>> Pseudocode.collectData(
 
 private fun <I : ControlFlowInfo<*>> Pseudocode.collectDataFromSubgraph(
         traversalOrder: TraversalOrder,
-        mergeDataWithLocalDeclarations: Boolean,
         edgesMap: MutableMap<Instruction, Edges<I>>,
         mergeEdges: (Instruction, Collection<I>) -> Edges<I>,
         updateEdge: (Instruction, Instruction, I) -> I,
@@ -98,30 +96,23 @@ private fun <I : ControlFlowInfo<*>> Pseudocode.collectDataFromSubgraph(
 
         if (instruction is LocalFunctionDeclarationInstruction) {
             val subroutinePseudocode = instruction.body
-            val previous = if (mergeDataWithLocalDeclarations) previousInstructions else Collections.emptyList()
             subroutinePseudocode.collectDataFromSubgraph(
-                    traversalOrder, mergeDataWithLocalDeclarations,
-                    edgesMap, mergeEdges, updateEdge, previous, changed, true)
-            if (mergeDataWithLocalDeclarations) {
-                val lastInstruction = subroutinePseudocode.getLastInstruction(traversalOrder)
-                val previousValue = edgesMap.get(instruction)
-                val newValue = edgesMap.get(lastInstruction)
-                val updatedValue =
-                        if (newValue == null)
-                            null
-                        else
-                            Edges(updateEdge(lastInstruction, instruction, newValue.incoming),
-                                  updateEdge(lastInstruction, instruction, newValue.outgoing))
-                updateEdgeDataForInstruction(instruction, previousValue, updatedValue, edgesMap, changed)
-                continue
+                    traversalOrder, edgesMap, mergeEdges, updateEdge, previousInstructions, changed, true)
+            val lastInstruction = subroutinePseudocode.getLastInstruction(traversalOrder)
+            val previousValue = edgesMap[instruction]
+            val newValue = edgesMap[lastInstruction]
+            val updatedValue = newValue?.let {
+                Edges(updateEdge(lastInstruction, instruction, it.incoming), updateEdge(lastInstruction, instruction, it.outgoing))
             }
+            updateEdgeDataForInstruction(instruction, previousValue, updatedValue, edgesMap, changed)
+            continue
         }
-        val previousDataValue = edgesMap.get(instruction)
+        val previousDataValue = edgesMap[instruction]
 
         val incomingEdgesData = HashSet<I>()
 
         for (previousInstruction in previousInstructions) {
-            val previousData = edgesMap.get(previousInstruction)
+            val previousData = edgesMap[previousInstruction]
             if (previousData != null) {
                 incomingEdgesData.add(updateEdge(
                         previousInstruction, instruction, previousData.outgoing))
diff --git a/compiler/frontend/src/org/jetbrains/kotlin/cfg/PseudocodeVariableDataCollector.kt b/compiler/frontend/src/org/jetbrains/kotlin/cfg/PseudocodeVariableDataCollector.kt
index c0b25ac78a3..fa97040924a 100644
--- a/compiler/frontend/src/org/jetbrains/kotlin/cfg/PseudocodeVariableDataCollector.kt
+++ b/compiler/frontend/src/org/jetbrains/kotlin/cfg/PseudocodeVariableDataCollector.kt
@@ -40,12 +40,11 @@ class PseudocodeVariableDataCollector(
 
     fun <I : ControlFlowInfo<*>> collectData(
             traversalOrder: TraversalOrder,
-            mergeDataWithLocalDeclarations: Boolean,
             initialInfo: I,
             instructionDataMergeStrategy: (Instruction, Collection<I>) -> Edges<I>
     ): Map<Instruction, Edges<I>> {
         return pseudocode.collectData(
-                traversalOrder, mergeDataWithLocalDeclarations,
+                traversalOrder,
                 instructionDataMergeStrategy,
                 { from, to, info -> filterOutVariablesOutOfScope(from, to, info) },
                 initialInfo
diff --git a/compiler/frontend/src/org/jetbrains/kotlin/cfg/PseudocodeVariablesData.kt b/compiler/frontend/src/org/jetbrains/kotlin/cfg/PseudocodeVariablesData.kt
index 1a33af1ceb1..40ecd4f56f3 100644
--- a/compiler/frontend/src/org/jetbrains/kotlin/cfg/PseudocodeVariablesData.kt
+++ b/compiler/frontend/src/org/jetbrains/kotlin/cfg/PseudocodeVariablesData.kt
@@ -89,9 +89,7 @@ class PseudocodeVariablesData(val pseudocode: Pseudocode, private val bindingCon
 
         val blockScopeVariableInfo = pseudocodeVariableDataCollector.blockScopeVariableInfo
 
-        return pseudocodeVariableDataCollector.collectData(
-                TraversalOrder.FORWARD, /*mergeDataWithLocalDeclarations=*/ true, InitControlFlowInfo()
-        ) {
+        return pseudocodeVariableDataCollector.collectData(TraversalOrder.FORWARD, InitControlFlowInfo()) {
             instruction: Instruction, incomingEdgesData: Collection<InitControlFlowInfo> ->
 
             val enterInstructionData = mergeIncomingEdgesDataForInitializers(instruction, incomingEdgesData, blockScopeVariableInfo)
@@ -148,9 +146,7 @@ class PseudocodeVariablesData(val pseudocode: Pseudocode, private val bindingCon
     // variable use
 
     val variableUseStatusData: Map<Instruction, Edges<UseControlFlowInfo>>
-        get() = pseudocodeVariableDataCollector.collectData(
-                TraversalOrder.BACKWARD, true, UseControlFlowInfo()
-        ) {
+        get() = pseudocodeVariableDataCollector.collectData(TraversalOrder.BACKWARD, UseControlFlowInfo()) {
             instruction: Instruction, incomingEdgesData: Collection<UseControlFlowInfo> ->
             val enterResult: UseControlFlowInfo