FE: properly clear the deferred generator stack

Before this commit the stack wasn't cleared for read variable case.
#KT-47168 Fixed

compiler/fir/fir2ir/tests-gen/org/jetbrains/kotlin/test/runners/codegen/FirBlackBoxCodegenTestGenerated.java

@@ -7538,6 +7538,12 @@ public class FirBlackBoxCodegenTestGenerated extends AbstractFirBlackBoxCodegenT
             runTest("compiler/testData/codegen/box/contracts/kt45236.kt");
         }
 
+        @Test
+        @TestMetadata("kt47168.kt")
+        public void testKt47168() throws Exception {
+            runTest("compiler/testData/codegen/box/contracts/kt47168.kt");
+        }
+
         @Test
         @TestMetadata("lambdaParameter.kt")
         public void testLambdaParameter() throws Exception {

compiler/frontend/cfg/src/org/jetbrains/kotlin/cfg/ControlFlowProcessor.kt

@@ -1574,19 +1574,18 @@ class ControlFlowProcessor(
                 }
             }
 
-            if (resolvedCall.resultingDescriptor is VariableDescriptor) {
+            val callInstruction = if (resolvedCall.resultingDescriptor is VariableDescriptor) {
                 // If a callee of the call is just a variable (without 'invoke'), 'read variable' is generated.
                 // todo : process arguments for such a case (KT-5387)
                 val callExpression =
                     callElement as? KtExpression ?: error("Variable-based call without callee expression: " + callElement.text)
                 assert(parameterValues.isEmpty()) { "Variable-based call with non-empty argument list: " + callElement.text }
-                return builder.readVariable(callExpression, resolvedCall, receivers)
+                builder.readVariable(callExpression, resolvedCall, receivers)
+            } else {
+                mark(resolvedCall.call.callElement)
+                builder.call(callElement, resolvedCall, receivers, parameterValues)
             }
-
+            deferredGeneratorsStack.pop().forEach { it.invoke(builder) }
-            mark(resolvedCall.call.callElement)
-            val callInstruction = builder.call(callElement, resolvedCall, receivers, parameterValues)
-            val deferredGeneratorsForCall = deferredGeneratorsStack.pop()
-            deferredGeneratorsForCall.forEach { it.invoke(builder) }
             return callInstruction
         }
 

compiler/testData/codegen/box/contracts/kt47168.kt

@@ -0,0 +1,16 @@
+// !USE_EXPERIMENTAL: kotlin.contracts.ExperimentalContracts
+// IGNORE_BACKEND: NATIVE
+import kotlin.contracts.*
+
+inline fun foo(x: () -> String, y: () -> String): String {
+    contract {
+        callsInPlace(x, InvocationKind.EXACTLY_ONCE)
+        callsInPlace(y, InvocationKind.EXACTLY_ONCE)
+    }
+    return x() + y()
+}
+
+fun box(): String {
+    val y = { "K" }
+    return foo({ "O" }, y)
+}

compiler/tests-common-new/tests-gen/org/jetbrains/kotlin/test/runners/codegen/BlackBoxCodegenTestGenerated.java

@@ -7538,6 +7538,12 @@ public class BlackBoxCodegenTestGenerated extends AbstractBlackBoxCodegenTest {
             runTest("compiler/testData/codegen/box/contracts/kt45236.kt");
         }
 
+        @Test
+        @TestMetadata("kt47168.kt")
+        public void testKt47168() throws Exception {
+            runTest("compiler/testData/codegen/box/contracts/kt47168.kt");
+        }
+
         @Test
         @TestMetadata("lambdaParameter.kt")
         public void testLambdaParameter() throws Exception {

compiler/tests-common-new/tests-gen/org/jetbrains/kotlin/test/runners/codegen/IrBlackBoxCodegenTestGenerated.java

@@ -7538,6 +7538,12 @@ public class IrBlackBoxCodegenTestGenerated extends AbstractIrBlackBoxCodegenTes
             runTest("compiler/testData/codegen/box/contracts/kt45236.kt");
         }
 
+        @Test
+        @TestMetadata("kt47168.kt")
+        public void testKt47168() throws Exception {
+            runTest("compiler/testData/codegen/box/contracts/kt47168.kt");
+        }
+
         @Test
         @TestMetadata("lambdaParameter.kt")
         public void testLambdaParameter() throws Exception {

compiler/tests-gen/org/jetbrains/kotlin/codegen/LightAnalysisModeTestGenerated.java

@@ -5744,6 +5744,11 @@ public class LightAnalysisModeTestGenerated extends AbstractLightAnalysisModeTes
             runTest("compiler/testData/codegen/box/contracts/kt45236.kt");
         }
 
+        @TestMetadata("kt47168.kt")
+        public void testKt47168() throws Exception {
+            runTest("compiler/testData/codegen/box/contracts/kt47168.kt");
+        }
+
         @TestMetadata("lambdaParameter.kt")
         public void testLambdaParameter() throws Exception {
             runTest("compiler/testData/codegen/box/contracts/lambdaParameter.kt");

js/js.tests/tests-gen/org/jetbrains/kotlin/js/test/es6/semantics/IrJsCodegenBoxES6TestGenerated.java

@@ -5018,6 +5018,11 @@ public class IrJsCodegenBoxES6TestGenerated extends AbstractIrJsCodegenBoxES6Tes
             runTest("compiler/testData/codegen/box/contracts/kt45236.kt");
         }
 
+        @TestMetadata("kt47168.kt")
+        public void testKt47168() throws Exception {
+            runTest("compiler/testData/codegen/box/contracts/kt47168.kt");
+        }
+
         @TestMetadata("lambdaParameter.kt")
         public void testLambdaParameter() throws Exception {
             runTest("compiler/testData/codegen/box/contracts/lambdaParameter.kt");

js/js.tests/tests-gen/org/jetbrains/kotlin/js/test/ir/semantics/IrJsCodegenBoxTestGenerated.java

@@ -4424,6 +4424,11 @@ public class IrJsCodegenBoxTestGenerated extends AbstractIrJsCodegenBoxTest {
             runTest("compiler/testData/codegen/box/contracts/kt45236.kt");
         }
 
+        @TestMetadata("kt47168.kt")
+        public void testKt47168() throws Exception {
+            runTest("compiler/testData/codegen/box/contracts/kt47168.kt");
+        }
+
         @TestMetadata("lambdaParameter.kt")
         public void testLambdaParameter() throws Exception {
             runTest("compiler/testData/codegen/box/contracts/lambdaParameter.kt");

js/js.tests/tests-gen/org/jetbrains/kotlin/js/test/semantics/JsCodegenBoxTestGenerated.java

@@ -4424,6 +4424,11 @@ public class JsCodegenBoxTestGenerated extends AbstractJsCodegenBoxTest {
             runTest("compiler/testData/codegen/box/contracts/kt45236.kt");
         }
 
+        @TestMetadata("kt47168.kt")
+        public void testKt47168() throws Exception {
+            runTest("compiler/testData/codegen/box/contracts/kt47168.kt");
+        }
+
         @TestMetadata("lambdaParameter.kt")
         public void testLambdaParameter() throws Exception {
             runTest("compiler/testData/codegen/box/contracts/lambdaParameter.kt");