Forbid val field initialization inside EXACLTY_ONCE lambda

unless the lambda is inline. This way, final field will remain final.

compiler/backend/src/org/jetbrains/kotlin/codegen/PropertyCodegen.java

@@ -422,14 +422,6 @@ public class PropertyCodegen {
         }
         modifiers |= getVisibilityForBackingField(propertyDescriptor, isDelegate);
 
-        // If val is initialized in EXACTLY_ONCE closure, other class from the same package initializes it
-        // so, its visibility should be package private and not final
-        if (!propertyDescriptor.isVar() &&
-            bindingContext.get(BindingContext.FIELD_CAPTURED_IN_EXACLY_ONCE_CLOSURE, propertyDescriptor) != null
-        ) {
-            modifiers &= ~(ACC_PRIVATE | ACC_FINAL);
-        }
-
         if (AsmUtil.isPropertyWithBackingFieldCopyInOuterClass(propertyDescriptor)) {
             ImplementationBodyCodegen parentBodyCodegen = (ImplementationBodyCodegen) memberCodegen.getParentCodegen();
             parentBodyCodegen.addCompanionObjectPropertyToCopy(propertyDescriptor, defaultValue);

compiler/fir/analysis-tests/tests/org/jetbrains/kotlin/fir/FirOldFrontendDiagnosticsTestGenerated.java

@@ -3816,6 +3816,11 @@ public class FirOldFrontendDiagnosticsTestGenerated extends AbstractFirOldFronte
             runTest("compiler/testData/diagnostics/tests/controlFlowAnalysis/fieldAsClassDelegate.kt");
         }
 
+        @TestMetadata("fieldInitialization.kt")
+        public void testFieldInitialization() throws Exception {
+            runTest("compiler/testData/diagnostics/tests/controlFlowAnalysis/fieldInitialization.kt");
+        }
+
         @TestMetadata("infiniteLoops.kt")
         public void testInfiniteLoops() throws Exception {
             runTest("compiler/testData/diagnostics/tests/controlFlowAnalysis/infiniteLoops.kt");

compiler/fir/fir2ir/tests/org/jetbrains/kotlin/codegen/ir/FirBlackBoxCodegenTestGenerated.java

@@ -5097,11 +5097,6 @@ public class FirBlackBoxCodegenTestGenerated extends AbstractFirBlackBoxCodegenT
             runTest("compiler/testData/codegen/box/contracts/exception.kt");
         }
 
-        @TestMetadata("field.kt")
-        public void testField() throws Exception {
-            runTest("compiler/testData/codegen/box/contracts/field.kt");
-        }
-
         @TestMetadata("forLoop.kt")
         public void testForLoop() throws Exception {
             runTest("compiler/testData/codegen/box/contracts/forLoop.kt");

compiler/frontend/src/org/jetbrains/kotlin/resolve/BindingContext.java

@@ -179,7 +179,6 @@ public interface BindingContext {
     WritableSlice<KtElement, Boolean> USED_AS_RESULT_OF_LAMBDA = Slices.createSimpleSetSlice();
 
     WritableSlice<VariableDescriptor, CaptureKind> CAPTURED_IN_CLOSURE = new BasicWritableSlice<>(DO_NOTHING);
-    WritableSlice<PropertyDescriptor, Boolean> FIELD_CAPTURED_IN_EXACLY_ONCE_CLOSURE = new BasicWritableSlice<>(DO_NOTHING);
     WritableSlice<KtDeclaration, PreliminaryDeclarationVisitor> PRELIMINARY_VISITOR = new BasicWritableSlice<>(DO_NOTHING);
 
     WritableSlice<Box<DeferredType>, Boolean> DEFERRED_TYPE = Slices.createCollectiveSetSlice();

compiler/frontend/src/org/jetbrains/kotlin/resolve/calls/checkers/CapturingInClosureChecker.kt

@@ -13,10 +13,10 @@ import org.jetbrains.kotlin.descriptors.*
 import org.jetbrains.kotlin.descriptors.impl.AnonymousFunctionDescriptor
 import org.jetbrains.kotlin.descriptors.impl.LocalVariableDescriptor
 import org.jetbrains.kotlin.descriptors.impl.ValueParameterDescriptorImpl
+import org.jetbrains.kotlin.diagnostics.Errors.CAPTURED_VAL_INITIALIZATION
 import org.jetbrains.kotlin.psi.*
 import org.jetbrains.kotlin.resolve.BindingContext
 import org.jetbrains.kotlin.resolve.BindingContext.CAPTURED_IN_CLOSURE
-import org.jetbrains.kotlin.resolve.BindingContext.FIELD_CAPTURED_IN_EXACLY_ONCE_CLOSURE
 import org.jetbrains.kotlin.resolve.BindingTrace
 import org.jetbrains.kotlin.resolve.DescriptorToSourceUtils
 import org.jetbrains.kotlin.resolve.calls.callUtil.getResolvedCall
@@ -35,6 +35,7 @@ class CapturingInClosureChecker : CallChecker {
         val variableDescriptor = variableResolvedCall.resultingDescriptor as? VariableDescriptor
         if (variableDescriptor != null) {
             checkCapturingInClosure(variableDescriptor, context.trace, context.scope)
+            checkFieldInExactlyOnceLambdaInitialization(variableDescriptor, context.trace, context.scope.ownerDescriptor, reportOn)
         }
     }
 
@@ -47,12 +48,23 @@ class CapturingInClosureChecker : CallChecker {
                 return
             }
         }
-        // Check whether a field is captured in EXACTLY_ONCE contract
+    }
-        if (variable !is PropertyDescriptor || scopeContainer !is AnonymousFunctionDescriptor) return
+
+    private fun checkFieldInExactlyOnceLambdaInitialization(
+        variable: VariableDescriptor,
+        trace: BindingTrace,
+        scopeContainer: DeclarationDescriptor,
+        reportOn: PsiElement
+    ) {
+        if (variable !is PropertyDescriptor || scopeContainer !is AnonymousFunctionDescriptor || variable.isVar) return
         val scopeDeclaration = DescriptorToSourceUtils.descriptorToDeclaration(scopeContainer) as? KtFunction ?: return
         if (scopeContainer.containingDeclaration !is ConstructorDescriptor) return
-        if (isExactlyOnceContract(trace.bindingContext, scopeDeclaration)) {
+        if (!isExactlyOnceContract(trace.bindingContext, scopeDeclaration)) return
-            trace.record(FIELD_CAPTURED_IN_EXACLY_ONCE_CLOSURE, variable)
+        if (trace.bindingContext[CAPTURED_IN_CLOSURE, variable] == CaptureKind.NOT_INLINE) return
+        val (callee, param) = getCalleeDescriptorAndParameter(trace.bindingContext, scopeDeclaration) ?: return
+        if (callee !is FunctionDescriptor) return
+        if (!callee.isInline || (param.isCrossinline || !InlineUtil.isInlineParameter(param))) {
+            trace.report(CAPTURED_VAL_INITIALIZATION.on(reportOn as KtExpression, variable))
         }
     }
 

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

@@ -1,26 +0,0 @@
-// !USE_EXPERIMENTAL: kotlin.contracts.ExperimentalContracts
-// IGNORE_BACKEND: NATIVE
-// WITH_RUNTIME
-// IGNORE_LIGHT_ANALYSIS
-
-import kotlin.contracts.*
-
-fun runOnce(action: () -> Unit) {
-    contract {
-        callsInPlace(action, InvocationKind.EXACTLY_ONCE)
-    }
-    action()
-}
-
-class Foo {
-    val res: String
-    init {
-        runOnce {
-            res = "OK"
-        }
-    }
-}
-
-fun box(): String {
-    return Foo().res
-}

compiler/testData/diagnostics/tests/controlFlowAnalysis/fieldInitialization.fir.kt

@@ -0,0 +1,60 @@
+// !LANGUAGE: +AllowContractsForCustomFunctions +UseCallsInPlaceEffect
+// !USE_EXPERIMENTAL: kotlin.internal.ContractsDsl
+
+import kotlin.contracts.*
+
+@kotlin.contracts.ExperimentalContracts
+inline fun inlineMe(block: () -> Unit) {
+    contract {
+        callsInPlace(block, InvocationKind.EXACTLY_ONCE)
+    }
+    block()
+}
+
+@kotlin.contracts.ExperimentalContracts
+inline fun crossinlineMe(crossinline block: () -> Unit) {
+    contract {
+        callsInPlace(block, InvocationKind.EXACTLY_ONCE)
+    }
+    block()
+}
+
+@Suppress("NOTHING_TO_INLINE")
+@kotlin.contracts.ExperimentalContracts
+inline fun noinlineMe(noinline block: () -> Unit) {
+    contract {
+        callsInPlace(block, InvocationKind.EXACTLY_ONCE)
+    }
+    block()
+}
+
+@kotlin.contracts.ExperimentalContracts
+fun notinline(block: () -> Unit) {
+    contract {
+        callsInPlace(block, InvocationKind.EXACTLY_ONCE)
+    }
+    block()
+}
+
+@kotlin.contracts.ExperimentalContracts
+class Test {
+    val a: String
+    val b: String
+    val c: String
+    val d: String
+
+    init {
+        inlineMe {
+            a = "allowed"
+        }
+        crossinlineMe {
+            b = "not allowed"
+        }
+        noinlineMe {
+            c = "not allowed"
+        }
+        notinline {
+            d = "not allowed"
+        }
+    }
+}

compiler/testData/diagnostics/tests/controlFlowAnalysis/fieldInitialization.kt

@@ -0,0 +1,60 @@
+// !LANGUAGE: +AllowContractsForCustomFunctions +UseCallsInPlaceEffect
+// !USE_EXPERIMENTAL: kotlin.internal.ContractsDsl
+
+import kotlin.contracts.*
+
+@kotlin.contracts.ExperimentalContracts
+inline fun inlineMe(block: () -> Unit) {
+    contract {
+        callsInPlace(block, InvocationKind.EXACTLY_ONCE)
+    }
+    block()
+}
+
+@kotlin.contracts.ExperimentalContracts
+inline fun crossinlineMe(crossinline block: () -> Unit) {
+    contract {
+        callsInPlace(block, InvocationKind.EXACTLY_ONCE)
+    }
+    block()
+}
+
+@Suppress("NOTHING_TO_INLINE")
+@kotlin.contracts.ExperimentalContracts
+inline fun noinlineMe(noinline block: () -> Unit) {
+    contract {
+        callsInPlace(block, InvocationKind.EXACTLY_ONCE)
+    }
+    block()
+}
+
+@kotlin.contracts.ExperimentalContracts
+fun notinline(block: () -> Unit) {
+    contract {
+        callsInPlace(block, InvocationKind.EXACTLY_ONCE)
+    }
+    block()
+}
+
+@kotlin.contracts.ExperimentalContracts
+class Test {
+    val a: String
+    val b: String
+    val c: String
+    val d: String
+
+    init {
+        inlineMe {
+            a = "allowed"
+        }
+        crossinlineMe {
+            <!CAPTURED_VAL_INITIALIZATION!>b<!> = "not allowed"
+        }
+        noinlineMe {
+            <!CAPTURED_VAL_INITIALIZATION!>c<!> = "not allowed"
+        }
+        notinline {
+            <!CAPTURED_VAL_INITIALIZATION!>d<!> = "not allowed"
+        }
+    }
+}

compiler/testData/diagnostics/tests/controlFlowAnalysis/fieldInitialization.txt

@@ -0,0 +1,24 @@
+package
+
+@kotlin.contracts.ExperimentalContracts public inline fun crossinlineMe(/*0*/ crossinline block: () -> kotlin.Unit): kotlin.Unit
+    CallsInPlace(block, EXACTLY_ONCE)
+
+@kotlin.contracts.ExperimentalContracts public inline fun inlineMe(/*0*/ block: () -> kotlin.Unit): kotlin.Unit
+    CallsInPlace(block, EXACTLY_ONCE)
+
+@kotlin.Suppress(names = {"NOTHING_TO_INLINE"}) @kotlin.contracts.ExperimentalContracts public inline fun noinlineMe(/*0*/ noinline block: () -> kotlin.Unit): kotlin.Unit
+    CallsInPlace(block, EXACTLY_ONCE)
+
+@kotlin.contracts.ExperimentalContracts public fun notinline(/*0*/ block: () -> kotlin.Unit): kotlin.Unit
+    CallsInPlace(block, EXACTLY_ONCE)
+
+@kotlin.contracts.ExperimentalContracts public final class Test {
+    public constructor Test()
+    public final val a: kotlin.String
+    public final val b: kotlin.String
+    public final val c: kotlin.String
+    public final val d: kotlin.String
+    public open override /*1*/ /*fake_override*/ fun equals(/*0*/ other: kotlin.Any?): kotlin.Boolean
+    public open override /*1*/ /*fake_override*/ fun hashCode(): kotlin.Int
+    public open override /*1*/ /*fake_override*/ fun toString(): kotlin.String
+}

compiler/testData/diagnostics/testsWithStdLib/contracts/controlflow/initialization/exactlyOnce/valDefiniteInitialization.kt

@@ -86,7 +86,7 @@ class DefiniteInitializationInInitSection {
     <!MUST_BE_INITIALIZED_OR_BE_ABSTRACT!>val y: Int<!>
 
     init {
-        myRun { x = 42 }
+        myRun { <!CAPTURED_VAL_INITIALIZATION!>x<!> = 42 }
         unknownRun { <!CAPTURED_MEMBER_VAL_INITIALIZATION!>y<!> = 239 }
     }
 }

compiler/tests/org/jetbrains/kotlin/checkers/DiagnosticsTestGenerated.java

@@ -3823,6 +3823,11 @@ public class DiagnosticsTestGenerated extends AbstractDiagnosticsTestWithFirVali
                 runTest("compiler/testData/diagnostics/tests/controlFlowAnalysis/fieldAsClassDelegate.kt");
             }
 
+            @TestMetadata("fieldInitialization.kt")
+            public void testFieldInitialization() throws Exception {
+                runTest("compiler/testData/diagnostics/tests/controlFlowAnalysis/fieldInitialization.kt");
+            }
+
             @TestMetadata("infiniteLoops.kt")
             public void testInfiniteLoops() throws Exception {
                 runTest("compiler/testData/diagnostics/tests/controlFlowAnalysis/infiniteLoops.kt");

compiler/tests/org/jetbrains/kotlin/checkers/javac/DiagnosticsUsingJavacTestGenerated.java

@@ -3818,6 +3818,11 @@ public class DiagnosticsUsingJavacTestGenerated extends AbstractDiagnosticsUsing
                 runTest("compiler/testData/diagnostics/tests/controlFlowAnalysis/fieldAsClassDelegate.kt");
             }
 
+            @TestMetadata("fieldInitialization.kt")
+            public void testFieldInitialization() throws Exception {
+                runTest("compiler/testData/diagnostics/tests/controlFlowAnalysis/fieldInitialization.kt");
+            }
+
             @TestMetadata("infiniteLoops.kt")
             public void testInfiniteLoops() throws Exception {
                 runTest("compiler/testData/diagnostics/tests/controlFlowAnalysis/infiniteLoops.kt");

compiler/tests/org/jetbrains/kotlin/codegen/BlackBoxCodegenTestGenerated.java

@@ -5127,11 +5127,6 @@ public class BlackBoxCodegenTestGenerated extends AbstractBlackBoxCodegenTest {
             runTest("compiler/testData/codegen/box/contracts/exception.kt");
         }
 
-        @TestMetadata("field.kt")
-        public void testField() throws Exception {
-            runTest("compiler/testData/codegen/box/contracts/field.kt");
-        }
-
         @TestMetadata("forLoop.kt")
         public void testForLoop() throws Exception {
             runTest("compiler/testData/codegen/box/contracts/forLoop.kt");

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

@@ -5127,11 +5127,6 @@ public class LightAnalysisModeTestGenerated extends AbstractLightAnalysisModeTes
             runTest("compiler/testData/codegen/box/contracts/exception.kt");
         }
 
-        @TestMetadata("field.kt")
-        public void testField() throws Exception {
-            runTest("compiler/testData/codegen/box/contracts/field.kt");
-        }
-
         @TestMetadata("forLoop.kt")
         public void testForLoop() throws Exception {
             runTest("compiler/testData/codegen/box/contracts/forLoop.kt");

compiler/tests/org/jetbrains/kotlin/codegen/ir/IrBlackBoxCodegenTestGenerated.java

@@ -5097,11 +5097,6 @@ public class IrBlackBoxCodegenTestGenerated extends AbstractIrBlackBoxCodegenTes
             runTest("compiler/testData/codegen/box/contracts/exception.kt");
         }
 
-        @TestMetadata("field.kt")
-        public void testField() throws Exception {
-            runTest("compiler/testData/codegen/box/contracts/field.kt");
-        }
-
         @TestMetadata("forLoop.kt")
         public void testForLoop() throws Exception {
             runTest("compiler/testData/codegen/box/contracts/forLoop.kt");

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

@@ -4127,11 +4127,6 @@ public class IrJsCodegenBoxES6TestGenerated extends AbstractIrJsCodegenBoxES6Tes
             runTest("compiler/testData/codegen/box/contracts/exception.kt");
         }
 
-        @TestMetadata("field.kt")
-        public void testField() throws Exception {
-            runTest("compiler/testData/codegen/box/contracts/field.kt");
-        }
-
         @TestMetadata("forLoop.kt")
         public void testForLoop() throws Exception {
             runTest("compiler/testData/codegen/box/contracts/forLoop.kt");

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

@@ -4137,11 +4137,6 @@ public class IrJsCodegenBoxTestGenerated extends AbstractIrJsCodegenBoxTest {
             runTest("compiler/testData/codegen/box/contracts/exception.kt");
         }
 
-        @TestMetadata("field.kt")
-        public void testField() throws Exception {
-            runTest("compiler/testData/codegen/box/contracts/field.kt");
-        }
-
         @TestMetadata("forLoop.kt")
         public void testForLoop() throws Exception {
             runTest("compiler/testData/codegen/box/contracts/forLoop.kt");

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

@@ -4137,11 +4137,6 @@ public class JsCodegenBoxTestGenerated extends AbstractJsCodegenBoxTest {
             runTest("compiler/testData/codegen/box/contracts/exception.kt");
         }
 
-        @TestMetadata("field.kt")
-        public void testField() throws Exception {
-            runTest("compiler/testData/codegen/box/contracts/field.kt");
-        }
-
         @TestMetadata("forLoop.kt")
         public void testForLoop() throws Exception {
             runTest("compiler/testData/codegen/box/contracts/forLoop.kt");