[FIR] Properly create edges from return expression to finally block

^KT-48376 Fixed

compiler/fir/analysis-tests/legacy-fir-tests/tests-gen/org/jetbrains/kotlin/fir/LazyBodyIsNotTouchedTilContractsPhaseTestGenerated.java

@@ -958,6 +958,11 @@ public class LazyBodyIsNotTouchedTilContractsPhaseTestGenerated extends Abstract
             runTest("compiler/fir/analysis-tests/testData/resolve/cfg/tryCatch.kt");
         }
 
+        @TestMetadata("variableInitializedInTryBlock.kt")
+        public void testVariableInitializedInTryBlock() throws Exception {
+            runTest("compiler/fir/analysis-tests/testData/resolve/cfg/variableInitializedInTryBlock.kt");
+        }
+
         @TestMetadata("when.kt")
         public void testWhen() throws Exception {
             runTest("compiler/fir/analysis-tests/testData/resolve/cfg/when.kt");

compiler/fir/analysis-tests/testData/resolve/cfg/variableInitializedInTryBlock.dot

@@ -0,0 +1,127 @@
+digraph variableInitializedInTryBlock_kt {
+    graph [nodesep=3]
+    node [shape=box penwidth=2]
+    edge [penwidth=2]
+
+    subgraph cluster_0 {
+        color=red
+        0 [label="Enter function test" style="filled" fillcolor=red];
+        subgraph cluster_1 {
+            color=blue
+            1 [label="Enter block"];
+            2 [label="Variable declaration: lval b: R|kotlin/Boolean|"];
+            subgraph cluster_2 {
+                color=blue
+                3 [label="Try expression enter"];
+                subgraph cluster_3 {
+                    color=blue
+                    4 [label="Try main block enter"];
+                    subgraph cluster_4 {
+                        color=blue
+                        5 [label="Enter block"];
+                        6 [label="Function call: R|/getStringOrNull|()"];
+                        7 [label="Exit lhs of ?:"];
+                        8 [label="Enter rhs of ?:"];
+                        9 [label="Jump: ^test Unit"];
+                        10 [label="Stub" style="filled" fillcolor=gray];
+                        11 [label="Lhs of ?: is not null"];
+                        12 [label="Exit ?:"];
+                        13 [label="Variable declaration: lval s: R|kotlin/String|"];
+                        14 [label="Access variable R|<local>/s|"];
+                        15 [label="Access variable R|kotlin/String.length|"];
+                        16 [label="Const: Int(0)"];
+                        17 [label="Equality operator !="];
+                        18 [label="Assignment: R|<local>/b|"];
+                        19 [label="Exit block"];
+                    }
+                    20 [label="Try main block exit"];
+                }
+                subgraph cluster_5 {
+                    color=blue
+                    21 [label="Enter finally"];
+                    subgraph cluster_6 {
+                        color=blue
+                        22 [label="Enter block"];
+                        23 [label="Function call: R|/test|()"];
+                        24 [label="Exit block"];
+                    }
+                    25 [label="Exit finally"];
+                }
+                26 [label="Try expression exit"];
+            }
+            27 [label="Access variable R|<local>/b|"];
+            28 [label="Function call: R|/takeBoolean|(...)"];
+            29 [label="Exit block"];
+        }
+        30 [label="Exit function test" style="filled" fillcolor=red];
+    }
+    0 -> {1};
+    1 -> {2};
+    2 -> {3};
+    3 -> {4};
+    3 -> {21}    [label=onUncaughtException];
+    4 -> {5};
+    5 -> {6};
+    6 -> {7};
+    7 -> {11 8};
+    8 -> {9};
+    9 -> {21}    [label="return@/test"];
+    9 -> {10} [style=dotted];
+    10 -> {12} [style=dotted];
+    11 -> {12};
+    12 -> {13};
+    13 -> {14};
+    14 -> {15};
+    15 -> {16};
+    16 -> {17};
+    17 -> {18};
+    18 -> {19};
+    19 -> {20};
+    20 -> {21};
+    21 -> {22};
+    22 -> {23};
+    23 -> {24};
+    24 -> {25};
+    25 -> {26};
+    25 -> {30}    [label="return@/test"];
+    26 -> {27};
+    27 -> {28};
+    28 -> {29};
+    29 -> {30};
+
+    subgraph cluster_7 {
+        color=red
+        31 [label="Enter function takeBoolean" style="filled" fillcolor=red];
+        subgraph cluster_8 {
+            color=blue
+            32 [label="Enter block"];
+            33 [label="Exit block"];
+        }
+        34 [label="Exit function takeBoolean" style="filled" fillcolor=red];
+    }
+    31 -> {32};
+    32 -> {33};
+    33 -> {34};
+
+    subgraph cluster_9 {
+        color=red
+        35 [label="Enter function getStringOrNull" style="filled" fillcolor=red];
+        subgraph cluster_10 {
+            color=blue
+            36 [label="Enter block"];
+            37 [label="Const: String(hello)"];
+            38 [label="Jump: ^getStringOrNull String(hello)"];
+            39 [label="Stub" style="filled" fillcolor=gray];
+            40 [label="Exit block" style="filled" fillcolor=gray];
+        }
+        41 [label="Exit function getStringOrNull" style="filled" fillcolor=red];
+    }
+    35 -> {36};
+    36 -> {37};
+    37 -> {38};
+    38 -> {41};
+    38 -> {39} [style=dotted];
+    39 -> {40} [style=dotted];
+    40 -> {41} [style=dotted];
+
+}

compiler/fir/analysis-tests/testData/resolve/cfg/variableInitializedInTryBlock.fir.txt

@@ -0,0 +1,18 @@
+FILE: variableInitializedInTryBlock.kt
+    public final fun test(): R|kotlin/Unit| {
+        lval b: R|kotlin/Boolean|
+        try {
+            lval s: R|kotlin/String| = R|/getStringOrNull|() ?: ^test Unit
+            R|<local>/b| = !=(R|<local>/s|.R|kotlin/String.length|, Int(0))
+        }
+        finally {
+            R|/test|()
+        }
+
+        R|/takeBoolean|(R|<local>/b|)
+    }
+    public final fun takeBoolean(b: R|kotlin/Boolean|): R|kotlin/Unit| {
+    }
+    public final fun getStringOrNull(): R|kotlin/String?| {
+        ^getStringOrNull String(hello)
+    }

compiler/fir/analysis-tests/testData/resolve/cfg/variableInitializedInTryBlock.kt

@@ -0,0 +1,19 @@
+// DUMP_CFG
+// ISSUE: KT-48376
+
+fun test() {
+    val b: Boolean
+    try {
+        val s = getStringOrNull() ?: return
+        b = s.length != 0
+    } finally {
+        test()
+    }
+    takeBoolean(b)
+}
+
+fun takeBoolean(b: Boolean) {}
+
+fun getStringOrNull(): String? {
+    return "hello"
+}

compiler/fir/analysis-tests/tests-gen/org/jetbrains/kotlin/test/runners/FirDiagnosticTestGenerated.java

@@ -1113,6 +1113,12 @@ public class FirDiagnosticTestGenerated extends AbstractFirDiagnosticTest {
                 runTest("compiler/fir/analysis-tests/testData/resolve/cfg/tryCatch.kt");
             }
 
+            @Test
+            @TestMetadata("variableInitializedInTryBlock.kt")
+            public void testVariableInitializedInTryBlock() throws Exception {
+                runTest("compiler/fir/analysis-tests/testData/resolve/cfg/variableInitializedInTryBlock.kt");
+            }
+
             @Test
             @TestMetadata("when.kt")
             public void testWhen() throws Exception {

compiler/fir/analysis-tests/tests-gen/org/jetbrains/kotlin/test/runners/FirDiagnosticsWithLightTreeTestGenerated.java

@@ -1113,6 +1113,12 @@ public class FirDiagnosticsWithLightTreeTestGenerated extends AbstractFirDiagnos
                 runTest("compiler/fir/analysis-tests/testData/resolve/cfg/tryCatch.kt");
             }
 
+            @Test
+            @TestMetadata("variableInitializedInTryBlock.kt")
+            public void testVariableInitializedInTryBlock() throws Exception {
+                runTest("compiler/fir/analysis-tests/testData/resolve/cfg/variableInitializedInTryBlock.kt");
+            }
+
             @Test
             @TestMetadata("when.kt")
             public void testWhen() throws Exception {

compiler/fir/resolve/src/org/jetbrains/kotlin/fir/resolve/dfa/cfg/ControlFlowGraphBuilder.kt

@@ -613,7 +613,21 @@ class ControlFlowGraphBuilder {
             is FirBreakExpression -> loopExitNodes[jump.target.labeledElement]
             else -> throw IllegalArgumentException("Unknown jump type: ${jump.render()}")
         }
-        addNodeWithJump(node, nextNode, isBack = jump is FirContinueExpression, trackJump = jump is FirReturnExpression)
+
+        val labelForFinallyBLock = if (jump is FirReturnExpression) {
+            ReturnPath(jump.target.labeledElement.symbol)
+        } else {
+            NormalPath
+        }
+
+        addNodeWithJump(
+            node,
+            nextNode,
+            isBack = jump is FirContinueExpression,
+            trackJump = jump is FirReturnExpression,
+            label = NormalPath,
+            labelForFinallyBLock = labelForFinallyBLock
+        )
         return node
     }
 
@@ -1411,6 +1425,7 @@ class ControlFlowGraphBuilder {
         preferredKind: EdgeKind = EdgeKind.Forward,
         isBack: Boolean = false,
         label: EdgeLabel = NormalPath,
+        labelForFinallyBLock: EdgeLabel = label,
         trackJump: Boolean = false
     ) {
         popAndAddEdge(node, preferredKind)
@@ -1423,13 +1438,18 @@ class ControlFlowGraphBuilder {
                     addBackEdge(node, targetNode, label = label)
                 }
             } else {
-                //go through all final nodes between node and target
+                // go through all final nodes between node and target
                 val finallyNodes = finallyBefore(targetNode)
                 val finalFrom = finallyNodes.fold(node) { from, (finallyEnter, tryExit) ->
-                    addEdgeIfNotExist(from, finallyEnter, propagateDeadness = false, label = label)
+                    addEdgeIfNotExist(from, finallyEnter, propagateDeadness = false, label = labelForFinallyBLock)
                     tryExit
                 }
-                addEdgeIfNotExist(finalFrom, targetNode, propagateDeadness = false, label = label)
+                addEdgeIfNotExist(
+                    finalFrom,
+                    targetNode,
+                    propagateDeadness = false,
+                    label = if (finallyNodes.isEmpty()) label else labelForFinallyBLock
+                )
                 if (trackJump && finallyNodes.isNotEmpty()) {
                     //actually we can store all returns like this, but not sure if it makes anything better
                     nonDirectJumps.put(targetNode, node)

idea/idea-frontend-fir/idea-fir-low-level-api/tests/org/jetbrains/kotlin/idea/fir/low/level/api/diagnostic/compiler/based/DiagnosisCompilerFirTestdataTestGenerated.java

@@ -1113,6 +1113,12 @@ public class DiagnosisCompilerFirTestdataTestGenerated extends AbstractDiagnosis
                 runTest("compiler/fir/analysis-tests/testData/resolve/cfg/tryCatch.kt");
             }
 
+            @Test
+            @TestMetadata("variableInitializedInTryBlock.kt")
+            public void testVariableInitializedInTryBlock() throws Exception {
+                runTest("compiler/fir/analysis-tests/testData/resolve/cfg/variableInitializedInTryBlock.kt");
+            }
+
             @Test
             @TestMetadata("when.kt")
             public void testWhen() throws Exception {