Prohibit protected method calls from inline function

#KT-21178 Fixed

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

@@ -11305,9 +11305,14 @@ public class FirDiagnosticsSmokeTestGenerated extends AbstractFirDiagnosticsSmok
             runTest("compiler/testData/diagnostics/tests/inline/propagation.kt");
         }
 
-        @TestMetadata("protectedDepecation.kt")
+        @TestMetadata("protectedCallDepecation.kt")
-        public void testProtectedDepecation() throws Exception {
+        public void testProtectedCallDepecation() throws Exception {
-            runTest("compiler/testData/diagnostics/tests/inline/protectedDepecation.kt");
+            runTest("compiler/testData/diagnostics/tests/inline/protectedCallDepecation.kt");
+        }
+
+        @TestMetadata("protectedCallError.kt")
+        public void testProtectedCallError() throws Exception {
+            runTest("compiler/testData/diagnostics/tests/inline/protectedCallError.kt");
         }
 
         @TestMetadata("publishedApi.kt")

compiler/frontend/src/org/jetbrains/kotlin/diagnostics/Errors.java

@@ -1086,6 +1086,7 @@ public interface Errors {
     DiagnosticFactory0<KtDeclaration> INLINE_PROPERTY_WITH_BACKING_FIELD = DiagnosticFactory0.create(ERROR, DECLARATION_SIGNATURE);
     DiagnosticFactory0<KtAnnotationEntry> NON_INTERNAL_PUBLISHED_API = DiagnosticFactory0.create(ERROR);
     DiagnosticFactory1<PsiElement, CallableDescriptor> PROTECTED_CALL_FROM_PUBLIC_INLINE = DiagnosticFactory1.create(WARNING);
+    DiagnosticFactory1<PsiElement, CallableDescriptor> PROTECTED_CALL_FROM_PUBLIC_INLINE_ERROR = DiagnosticFactory1.create(ERROR);
     DiagnosticFactory2<KtElement, KtExpression, DeclarationDescriptor> INVALID_DEFAULT_FUNCTIONAL_PARAMETER_FOR_INLINE = DiagnosticFactory2.create(ERROR);
     DiagnosticFactory2<KtElement, KtExpression, DeclarationDescriptor> NOT_SUPPORTED_INLINE_PARAMETER_IN_INLINE_PARAMETER_DEFAULT_VALUE = DiagnosticFactory2.create(ERROR);
 

compiler/frontend/src/org/jetbrains/kotlin/diagnostics/rendering/DefaultErrorMessages.java

@@ -975,6 +975,7 @@ public class DefaultErrorMessages {
         MAP.put(INLINE_PROPERTY_WITH_BACKING_FIELD, "Inline property cannot have backing field");
         MAP.put(NON_INTERNAL_PUBLISHED_API, "@PublishedApi annotation is only applicable for internal declaration");
         MAP.put(PROTECTED_CALL_FROM_PUBLIC_INLINE, "Protected function call from public-API inline function is deprecated", NAME);
+        MAP.put(PROTECTED_CALL_FROM_PUBLIC_INLINE_ERROR, "Protected function call from public-API inline function is prohibited", NAME);
         MAP.put(INVALID_DEFAULT_FUNCTIONAL_PARAMETER_FOR_INLINE, "Invalid default value for inline parameter: ''{0}''. Only lambdas, anonymous functions, and callable references are supported", ELEMENT_TEXT, SHORT_NAMES_IN_TYPES);
         MAP.put(NOT_SUPPORTED_INLINE_PARAMETER_IN_INLINE_PARAMETER_DEFAULT_VALUE, "Usage of inline parameter ''{0}'' in default value for another inline parameter is not supported", ELEMENT_TEXT, SHORT_NAMES_IN_TYPES);
         //Inline non locals

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

@@ -21,7 +21,6 @@ import org.jetbrains.kotlin.builtins.isBuiltinFunctionalType
 import org.jetbrains.kotlin.config.LanguageFeature
 import org.jetbrains.kotlin.contracts.parsing.isFromContractDsl
 import org.jetbrains.kotlin.descriptors.*
-import org.jetbrains.kotlin.diagnostics.Errors
 import org.jetbrains.kotlin.diagnostics.Errors.*
 import org.jetbrains.kotlin.lexer.KtTokens
 import org.jetbrains.kotlin.psi.*
@@ -58,10 +57,13 @@ internal class InlineChecker(private val descriptor: FunctionDescriptor) : CallC
 
     private var supportDefaultValueInline by Delegates.notNull<Boolean>()
 
+    private var prohibitProtectedCallFromInline by Delegates.notNull<Boolean>()
+
     override fun check(resolvedCall: ResolvedCall<*>, reportOn: PsiElement, context: CallCheckerContext) {
         val expression = resolvedCall.call.calleeExpression ?: return
 
         supportDefaultValueInline = context.languageVersionSettings.supportsFeature(LanguageFeature.InlineDefaultFunctionalParameters)
+        prohibitProtectedCallFromInline = context.languageVersionSettings.supportsFeature(LanguageFeature.ProhibitProtectedCallFromInline)
 
         //checking that only invoke or inlinable extension called on function parameter
         val targetDescriptor = resolvedCall.resultingDescriptor
@@ -227,7 +229,7 @@ internal class InlineChecker(private val descriptor: FunctionDescriptor) : CallC
         expression: KtElement
     ) {
         if (targetDescriptor.original === descriptor) {
-            context.trace.report(Errors.RECURSION_IN_INLINE.on(expression, expression, descriptor))
+            context.trace.report(RECURSION_IN_INLINE.on(expression, expression, descriptor))
         }
     }
 
@@ -258,7 +260,7 @@ internal class InlineChecker(private val descriptor: FunctionDescriptor) : CallC
         if (isInlineFunPublicOrPublishedApi &&
             !isCalledFunPublicOrPublishedApi &&
             calledDescriptor.visibility !== Visibilities.LOCAL) {
-            context.trace.report(Errors.NON_PUBLIC_CALL_FROM_PUBLIC_INLINE.on(expression, calledDescriptor, descriptor))
+            context.trace.report(NON_PUBLIC_CALL_FROM_PUBLIC_INLINE.on(expression, calledDescriptor, descriptor))
         } else {
             checkPrivateClassMemberAccess(calledDescriptor, expression, context)
         }
@@ -267,7 +269,11 @@ internal class InlineChecker(private val descriptor: FunctionDescriptor) : CallC
             isInlineFunPublicOrPublishedApi &&
             inlineFunEffectiveVisibility.toVisibility() !== Visibilities.PROTECTED &&
             calledFunEffectiveVisibility.toVisibility() === Visibilities.PROTECTED) {
-            context.trace.report(Errors.PROTECTED_CALL_FROM_PUBLIC_INLINE.on(expression, calledDescriptor))
+            if (prohibitProtectedCallFromInline) {
+                context.trace.report(PROTECTED_CALL_FROM_PUBLIC_INLINE_ERROR.on(expression, calledDescriptor))
+            } else {
+                context.trace.report(PROTECTED_CALL_FROM_PUBLIC_INLINE.on(expression, calledDescriptor))
+            }
         }
     }
 
@@ -278,7 +284,7 @@ internal class InlineChecker(private val descriptor: FunctionDescriptor) : CallC
     ) {
         if (!isEffectivelyPrivateApiFunction) {
             if (declarationDescriptor.isInsidePrivateClass) {
-                context.trace.report(Errors.PRIVATE_CLASS_MEMBER_FROM_INLINE.on(expression, declarationDescriptor, descriptor))
+                context.trace.report(PRIVATE_CLASS_MEMBER_FROM_INLINE.on(expression, declarationDescriptor, descriptor))
             }
         }
     }

compiler/testData/diagnostics/tests/inline/protectedCallDepecation.kt

@@ -1,3 +1,4 @@
+// !LANGUAGE: -ProhibitProtectedCallFromInline
 // !DIAGNOSTICS: -EXPOSED_PARAMETER_TYPE -NOTHING_TO_INLINE
 
 // FILE: JavaClass.java

compiler/testData/diagnostics/tests/inline/protectedCallError.kt

@@ -0,0 +1,102 @@
+// !LANGUAGE: +ProhibitProtectedCallFromInline
+// !DIAGNOSTICS: -EXPOSED_PARAMETER_TYPE -NOTHING_TO_INLINE
+
+// FILE: JavaClass.java
+
+
+public abstract class JavaClass {
+    protected void bind() {}
+}
+
+// FILE: main.kt
+open class A {
+    protected fun test() {}
+
+    protected val z: String = "1"
+
+    public var zVar: String = "1"
+        protected set(<!UNUSED_PARAMETER!>value<!>) {}
+
+    inline fun call() {
+        <!PROTECTED_CALL_FROM_PUBLIC_INLINE_ERROR!>test<!>()
+        <!PROTECTED_CALL_FROM_PUBLIC_INLINE_ERROR!>z<!>
+        zVar
+        <!PROTECTED_CALL_FROM_PUBLIC_INLINE_ERROR!>zVar<!> = "123"
+    }
+
+    internal inline fun callFromInternal() {
+        test()
+        zVar
+        zVar = "123"
+    }
+
+    @PublishedApi
+    internal inline fun callFromPublished() {
+        <!PROTECTED_CALL_FROM_PUBLIC_INLINE_ERROR!>test<!>()
+        <!PROTECTED_CALL_FROM_PUBLIC_INLINE_ERROR!>z<!>
+        zVar
+        <!PROTECTED_CALL_FROM_PUBLIC_INLINE_ERROR!>zVar<!> = "123"
+    }
+
+    protected inline fun callFromProtected() {
+        test()
+        zVar
+        zVar = "123"
+    }
+
+}
+
+class B : A() {
+    inline fun testB() {
+        <!PROTECTED_CALL_FROM_PUBLIC_INLINE_ERROR!>test<!>()
+    }
+}
+
+class C : JavaClass() {
+    inline fun call() {
+        <!PROTECTED_CALL_FROM_PUBLIC_INLINE_ERROR!>bind<!>()
+    }
+
+    internal inline fun callFromInternal() {
+        bind()
+    }
+
+    protected inline fun callFromProtected() {
+        bind()
+    }
+
+    @PublishedApi
+    internal inline fun callFromPublished() {
+        <!PROTECTED_CALL_FROM_PUBLIC_INLINE_ERROR!>bind<!>()
+    }
+}
+
+
+internal class AInternal {
+    protected fun test() {}
+
+    protected val z: String = "1"
+
+    public var zVar: String = "1"
+        protected set(<!UNUSED_PARAMETER!>value<!>) {}
+
+
+    inline fun call() {
+        test()
+    }
+
+    @PublishedApi
+    internal inline fun call2() {
+        test()
+    }
+}
+
+private class X {
+
+    public class Z : A() {
+        public inline fun effictivelyNonPublic() {
+            test()
+        }
+    }
+
+}

compiler/testData/diagnostics/tests/inline/protectedCallError.txt

@@ -0,0 +1,84 @@
+package
+
+public open class A {
+    public constructor A()
+    protected final val z: kotlin.String = "1"
+    public final var zVar: kotlin.String
+    public final inline fun call(): kotlin.Unit
+    internal final inline fun callFromInternal(): kotlin.Unit
+    protected final inline fun callFromProtected(): kotlin.Unit
+    @kotlin.PublishedApi internal final inline fun callFromPublished(): kotlin.Unit
+    public open override /*1*/ /*fake_override*/ fun equals(/*0*/ other: kotlin.Any?): kotlin.Boolean
+    public open override /*1*/ /*fake_override*/ fun hashCode(): kotlin.Int
+    protected final fun test(): kotlin.Unit
+    public open override /*1*/ /*fake_override*/ fun toString(): kotlin.String
+}
+
+internal final class AInternal {
+    public constructor AInternal()
+    protected final val z: kotlin.String = "1"
+    public final var zVar: kotlin.String
+    public final inline fun call(): kotlin.Unit
+    @kotlin.PublishedApi internal final inline fun call2(): kotlin.Unit
+    public open override /*1*/ /*fake_override*/ fun equals(/*0*/ other: kotlin.Any?): kotlin.Boolean
+    public open override /*1*/ /*fake_override*/ fun hashCode(): kotlin.Int
+    protected final fun test(): kotlin.Unit
+    public open override /*1*/ /*fake_override*/ fun toString(): kotlin.String
+}
+
+public final class B : A {
+    public constructor B()
+    protected final override /*1*/ /*fake_override*/ val z: kotlin.String
+    public final override /*1*/ /*fake_override*/ var zVar: kotlin.String
+    public final override /*1*/ inline /*fake_override*/ fun call(): kotlin.Unit
+    internal final override /*1*/ inline /*fake_override*/ fun callFromInternal(): kotlin.Unit
+    protected final override /*1*/ inline /*fake_override*/ fun callFromProtected(): kotlin.Unit
+    @kotlin.PublishedApi internal final override /*1*/ inline /*fake_override*/ fun callFromPublished(): kotlin.Unit
+    public open override /*1*/ /*fake_override*/ fun equals(/*0*/ other: kotlin.Any?): kotlin.Boolean
+    public open override /*1*/ /*fake_override*/ fun hashCode(): kotlin.Int
+    protected final override /*1*/ /*fake_override*/ fun test(): kotlin.Unit
+    public final inline fun testB(): kotlin.Unit
+    public open override /*1*/ /*fake_override*/ fun toString(): kotlin.String
+}
+
+public final class C : JavaClass {
+    public constructor C()
+    protected/*protected and package*/ open override /*1*/ /*fake_override*/ fun bind(): kotlin.Unit
+    public final inline fun call(): kotlin.Unit
+    internal final inline fun callFromInternal(): kotlin.Unit
+    protected final inline fun callFromProtected(): kotlin.Unit
+    @kotlin.PublishedApi internal final inline fun callFromPublished(): kotlin.Unit
+    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
+}
+
+public abstract class JavaClass {
+    public constructor JavaClass()
+    protected/*protected and package*/ open fun bind(): kotlin.Unit
+    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
+}
+
+private final class X {
+    public constructor X()
+    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
+
+    public final class Z : A {
+        public constructor Z()
+        protected final override /*1*/ /*fake_override*/ val z: kotlin.String
+        public final override /*1*/ /*fake_override*/ var zVar: kotlin.String
+        public final override /*1*/ inline /*fake_override*/ fun call(): kotlin.Unit
+        internal final override /*1*/ inline /*fake_override*/ fun callFromInternal(): kotlin.Unit
+        protected final override /*1*/ inline /*fake_override*/ fun callFromProtected(): kotlin.Unit
+        @kotlin.PublishedApi internal final override /*1*/ inline /*fake_override*/ fun callFromPublished(): kotlin.Unit
+        public final inline fun effictivelyNonPublic(): kotlin.Unit
+        public open override /*1*/ /*fake_override*/ fun equals(/*0*/ other: kotlin.Any?): kotlin.Boolean
+        public open override /*1*/ /*fake_override*/ fun hashCode(): kotlin.Int
+        protected final override /*1*/ /*fake_override*/ fun test(): kotlin.Unit
+        public open override /*1*/ /*fake_override*/ fun toString(): kotlin.String
+    }
+}

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

@@ -11312,9 +11312,14 @@ public class DiagnosticsTestGenerated extends AbstractDiagnosticsTest {
                 runTest("compiler/testData/diagnostics/tests/inline/propagation.kt");
             }
 
-            @TestMetadata("protectedDepecation.kt")
+            @TestMetadata("protectedCallDepecation.kt")
-            public void testProtectedDepecation() throws Exception {
+            public void testProtectedCallDepecation() throws Exception {
-                runTest("compiler/testData/diagnostics/tests/inline/protectedDepecation.kt");
+                runTest("compiler/testData/diagnostics/tests/inline/protectedCallDepecation.kt");
+            }
+
+            @TestMetadata("protectedCallError.kt")
+            public void testProtectedCallError() throws Exception {
+                runTest("compiler/testData/diagnostics/tests/inline/protectedCallError.kt");
             }
 
             @TestMetadata("publishedApi.kt")

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

@@ -11307,9 +11307,14 @@ public class DiagnosticsUsingJavacTestGenerated extends AbstractDiagnosticsUsing
                 runTest("compiler/testData/diagnostics/tests/inline/propagation.kt");
             }
 
-            @TestMetadata("protectedDepecation.kt")
+            @TestMetadata("protectedCallDepecation.kt")
-            public void testProtectedDepecation() throws Exception {
+            public void testProtectedCallDepecation() throws Exception {
-                runTest("compiler/testData/diagnostics/tests/inline/protectedDepecation.kt");
+                runTest("compiler/testData/diagnostics/tests/inline/protectedCallDepecation.kt");
+            }
+
+            @TestMetadata("protectedCallError.kt")
+            public void testProtectedCallError() throws Exception {
+                runTest("compiler/testData/diagnostics/tests/inline/protectedCallError.kt");
             }
 
             @TestMetadata("publishedApi.kt")

compiler/util/src/org/jetbrains/kotlin/config/LanguageVersionSettings.kt

@@ -114,6 +114,7 @@ enum class LanguageFeature(
     TrailingCommas(KOTLIN_1_4),
     ProhibitInvisibleAbstractMethodsInSuperclasses(KOTLIN_1_4, kind = BUG_FIX),
     ProhibitNonReifiedArraysAsReifiedTypeArguments(KOTLIN_1_4, kind = BUG_FIX),
+    ProhibitProtectedCallFromInline(KOTLIN_1_4, kind = BUG_FIX),
 
     ProperVisibilityForCompanionObjectInstanceField(sinceVersion = null, kind = BUG_FIX),
     // Temporarily disabled, see KT-27084/KT-22379