[FIR] KT-37009: Fix loss of bound smart-cast due to synthetic removal

compiler/fir/resolve/src/org/jetbrains/kotlin/fir/resolve/dfa/FirDataFlowAnalyzer.kt

@@ -552,7 +552,7 @@ abstract class FirDataFlowAnalyzer<FLOW : Flow>(
                 flow,
                 variable notEq null,
                 shouldFork,
-                shouldRemoveSynthetics = true
+                shouldRemoveSynthetics = false
             )
         }
 

compiler/fir/resolve/src/org/jetbrains/kotlin/fir/resolve/dfa/PersistentLogicSystem.kt

@@ -257,6 +257,7 @@ abstract class PersistentLogicSystem(context: ConeInferenceContext) : LogicSyste
     }
 
     override fun removeAllAboutVariable(flow: PersistentFlow, variable: RealVariable) {
+        flow.logicStatements -= variable
         flow.approvedTypeStatements -= variable
         flow.approvedTypeStatementsDiff -= variable
         // TODO: should we search variable in all logic statements?

compiler/fir/resolve/testData/resolve/smartcasts/boundSmartcasts/functionCallBound.dot

@@ -0,0 +1,139 @@
+digraph functionCallBound_kt {
+    graph [splines=ortho nodesep=3]
+    node [shape=box penwidth=2]
+    edge [penwidth=2]
+
+    subgraph cluster_0 {
+        color=red
+        0 [label="Enter function <init>" style="filled" fillcolor=red];
+        1 [label="Exit function <init>" style="filled" fillcolor=red];
+    }
+
+    0 -> {1};
+
+    subgraph cluster_1 {
+        color=red
+        2 [label="Enter function <init>" style="filled" fillcolor=red];
+        3 [label="Exit function <init>" style="filled" fillcolor=red];
+    }
+
+    2 -> {3};
+
+    subgraph cluster_2 {
+        color=red
+        4 [label="Enter function getter" style="filled" fillcolor=red];
+        5 [label="Exit function getter" style="filled" fillcolor=red];
+    }
+
+    4 -> {5};
+
+    subgraph cluster_3 {
+        color=red
+        6 [label="Enter property" style="filled" fillcolor=red];
+        7 [label="Access variable R|<local>/data|"];
+        8 [label="Exit property" style="filled" fillcolor=red];
+    }
+
+    6 -> {7};
+    7 -> {8};
+
+    subgraph cluster_4 {
+        color=red
+        9 [label="Enter function isOk" style="filled" fillcolor=red];
+        10 [label="Const: Boolean(true)"];
+        11 [label="Jump: ^isOk Boolean(true)"];
+        12 [label="Stub" style="filled" fillcolor=gray];
+        13 [label="Exit function isOk" style="filled" fillcolor=red];
+    }
+
+    9 -> {10};
+    10 -> {11};
+    11 -> {13};
+    11 -> {12} [style=dotted];
+    12 -> {13} [style=dotted];
+
+    subgraph cluster_5 {
+        color=red
+        14 [label="Enter function check" style="filled" fillcolor=red];
+        subgraph cluster_6 {
+            color=blue
+            15 [label="Enter when"];
+            subgraph cluster_7 {
+                color=blue
+                16 [label="Enter when branch condition "];
+                17 [label="Access variable R|<local>/base|"];
+                18 [label="Type operator: (R|<local>/base| as? R|Sub|)"];
+                19 [label="Enter safe call"];
+                20 [label="Function call: (R|<local>/base| as? R|Sub|)?.R|/isOk|()"];
+                21 [label="Exit safe call"];
+                22 [label="Const: Boolean(true)"];
+                23 [label="Operator =="];
+                24 [label="Exit when branch condition"];
+            }
+            subgraph cluster_8 {
+                color=blue
+                25 [label="Enter when branch condition else"];
+                26 [label="Exit when branch condition"];
+            }
+            27 [label="Enter when branch result"];
+            subgraph cluster_9 {
+                color=blue
+                28 [label="Enter block"];
+                29 [label="Access variable R|<local>/base|"];
+                30 [label="Exit block"];
+            }
+            31 [label="Exit when branch result"];
+            32 [label="Enter when branch result"];
+            subgraph cluster_10 {
+                color=blue
+                33 [label="Enter block"];
+                34 [label="Access variable R|<local>/base|"];
+                35 [label="Access variable R|/Sub.data|"];
+                36 [label="Exit block"];
+            }
+            37 [label="Exit when branch result"];
+            38 [label="Exit when"];
+        }
+        39 [label="Jump: ^check when () {
+    ==((R|<local>/base| as? R|Sub|)?.R|/isOk|(), Boolean(true)) ->  {
+        R|<local>/base|.R|/Sub.data|
+    }
+    else ->  {
+        R|<local>/base|
+    }
+}
+"];
+        40 [label="Stub" style="filled" fillcolor=gray];
+        41 [label="Exit function check" style="filled" fillcolor=red];
+    }
+
+    14 -> {15};
+    15 -> {16};
+    16 -> {17};
+    17 -> {18};
+    18 -> {19 21};
+    19 -> {20};
+    20 -> {21};
+    21 -> {22};
+    22 -> {23};
+    23 -> {24};
+    24 -> {32 25};
+    25 -> {26};
+    26 -> {27};
+    27 -> {28};
+    28 -> {29};
+    29 -> {30};
+    30 -> {31};
+    31 -> {38};
+    32 -> {33};
+    33 -> {34};
+    34 -> {35};
+    35 -> {36};
+    36 -> {37};
+    37 -> {38};
+    38 -> {39};
+    39 -> {41};
+    39 -> {40} [style=dotted];
+    40 -> {41} [style=dotted];
+
+}

compiler/fir/resolve/testData/resolve/smartcasts/boundSmartcasts/functionCallBound.kt

@@ -0,0 +1,18 @@
+// !DUMP_CFG
+
+open class Base
+class Sub(val data: Base): Base()
+
+fun Sub.isOk() = true
+
+fun check(base: Base): Base =
+    when {
+        (base as? Sub)?.isOk() == true -> {
+            base.data
+        }
+        else -> {
+            base
+        }
+    }
+
+

compiler/fir/resolve/testData/resolve/smartcasts/boundSmartcasts/functionCallBound.txt

@@ -0,0 +1,30 @@
+FILE: functionCallBound.kt
+    public open class Base : R|kotlin/Any| {
+        public constructor(): R|Base| {
+            super<R|kotlin/Any|>()
+        }
+
+    }
+    public final class Sub : R|Base| {
+        public constructor(data: R|Base|): R|Sub| {
+            super<R|Base|>()
+        }
+
+        public final val data: R|Base| = R|<local>/data|
+            public get(): R|Base|
+
+    }
+    public final fun R|Sub|.isOk(): R|kotlin/Boolean| {
+        ^isOk Boolean(true)
+    }
+    public final fun check(base: R|Base|): R|Base| {
+        ^check when () {
+            ==((R|<local>/base| as? R|Sub|)?.R|/isOk|(), Boolean(true)) ->  {
+                R|<local>/base|.R|/Sub.data|
+            }
+            else ->  {
+                R|<local>/base|
+            }
+        }
+
+    }

compiler/fir/resolve/tests/org/jetbrains/kotlin/fir/FirDiagnosticsTestGenerated.java

@@ -1535,6 +1535,11 @@ public class FirDiagnosticsTestGenerated extends AbstractFirDiagnosticsTest {
             public void testBoundSmartcastsInBranches() throws Exception {
                 runTest("compiler/fir/resolve/testData/resolve/smartcasts/boundSmartcasts/boundSmartcastsInBranches.kt");
             }
+
+            @TestMetadata("functionCallBound.kt")
+            public void testFunctionCallBound() throws Exception {
+                runTest("compiler/fir/resolve/testData/resolve/smartcasts/boundSmartcasts/functionCallBound.kt");
+            }
         }
 
         @TestMetadata("compiler/fir/resolve/testData/resolve/smartcasts/controlStructures")

compiler/fir/resolve/tests/org/jetbrains/kotlin/fir/FirDiagnosticsWithLightTreeTestGenerated.java

@@ -1535,6 +1535,11 @@ public class FirDiagnosticsWithLightTreeTestGenerated extends AbstractFirDiagnos
             public void testBoundSmartcastsInBranches() throws Exception {
                 runTest("compiler/fir/resolve/testData/resolve/smartcasts/boundSmartcasts/boundSmartcastsInBranches.kt");
             }
+
+            @TestMetadata("functionCallBound.kt")
+            public void testFunctionCallBound() throws Exception {
+                runTest("compiler/fir/resolve/testData/resolve/smartcasts/boundSmartcasts/functionCallBound.kt");
+            }
         }
 
         @TestMetadata("compiler/fir/resolve/testData/resolve/smartcasts/controlStructures")

compiler/testData/diagnostics/tests/smartCasts/castchecks/basicOff.fir.kt

@@ -19,8 +19,8 @@ fun g(a: SomeClass?) {
     val b = (a as? SomeSubClass)?.foo
     if (b != null) {
         // 'a' can be cast to SomeSubClass
-        a.<!INAPPLICABLE_CANDIDATE!>hashCode<!>()
+        a.hashCode()
-        a.<!UNRESOLVED_REFERENCE!>foo<!>
+        a.foo
         (a as? SomeSubClass).<!INAPPLICABLE_CANDIDATE!>foo<!>
         (a as SomeSubClass).foo
     }

compiler/testData/diagnostics/tests/smartCasts/castchecks/basicOn.fir.kt

@@ -19,8 +19,8 @@ fun g(a: SomeClass?) {
     val b = (a as? SomeSubClass)?.foo
     if (b != null) {
         // 'a' can be cast to SomeSubClass
-        a.<!INAPPLICABLE_CANDIDATE!>hashCode<!>()
+        a.hashCode()
-        a.<!UNRESOLVED_REFERENCE!>foo<!>
+        a.foo
         (a as? SomeSubClass).<!INAPPLICABLE_CANDIDATE!>foo<!>
         (a as SomeSubClass).foo
     }

compiler/testData/diagnostics/tests/smartCasts/castchecks/variables.fir.kt

@@ -27,8 +27,8 @@ fun g(a: SomeClass?) {
     c = Impl
     if (c != null) {
         // 'a' cannot be cast to SomeSubClass
-        a.hashCode()
+        a.<!INAPPLICABLE_CANDIDATE!>hashCode<!>()
-        a.foo
+        a.<!UNRESOLVED_REFERENCE!>foo<!>
         (a as? SomeSubClass).<!INAPPLICABLE_CANDIDATE!>foo<!>
         c.hashCode()
         c.foo

compiler/testData/diagnostics/tests/smartCasts/safecalls/safeAccessReceiverNotNull.fir.kt

@@ -63,7 +63,7 @@ fun kt4565_2(a: SomeClass?) {
     }
     val extra = (a as? SubClass)?.extra
     if (extra != null) {
-        a.<!UNRESOLVED_REFERENCE!>extra<!>.<!UNRESOLVED_REFERENCE!>hashCode<!>()
+        a.extra.hashCode()
     }
 }