Report warning on @Synchronized on inline methods

Until KT-27310 is supported, we warn users that this has no effect.

 #KT-29884 Fixed

compiler/frontend.java/src/org/jetbrains/kotlin/resolve/jvm/checkers/SynchronizedOnInlineMethodChecker.kt

@@ -0,0 +1,27 @@
+/*
+ * Copyright 2010-2019 JetBrains s.r.o. Use of this source code is governed by the Apache 2.0 license
+ * that can be found in the license/LICENSE.txt file.
+ */
+
+package org.jetbrains.kotlin.resolve.jvm.checkers
+
+import org.jetbrains.kotlin.descriptors.DeclarationDescriptor
+import org.jetbrains.kotlin.descriptors.FunctionDescriptor
+import org.jetbrains.kotlin.psi.KtDeclaration
+import org.jetbrains.kotlin.resolve.DescriptorToSourceUtils
+import org.jetbrains.kotlin.resolve.checkers.DeclarationChecker
+import org.jetbrains.kotlin.resolve.checkers.DeclarationCheckerContext
+import org.jetbrains.kotlin.resolve.jvm.annotations.findSynchronizedAnnotation
+import org.jetbrains.kotlin.resolve.jvm.diagnostics.ErrorsJvm
+
+object SynchronizedOnInlineMethodChecker : DeclarationChecker {
+    override fun check(declaration: KtDeclaration, descriptor: DeclarationDescriptor, context: DeclarationCheckerContext) {
+        if (descriptor is FunctionDescriptor && descriptor.isInline) {
+            val annotation = descriptor.findSynchronizedAnnotation()
+            if (annotation != null) {
+                val reportOn = DescriptorToSourceUtils.getSourceFromAnnotation(annotation) ?: declaration
+                context.trace.report(ErrorsJvm.SYNCHRONIZED_ON_INLINE.on(reportOn))
+            }
+        }
+    }
+}

compiler/frontend.java/src/org/jetbrains/kotlin/resolve/jvm/diagnostics/DefaultErrorMessagesJvm.java

@@ -57,6 +57,7 @@ public class DefaultErrorMessagesJvm implements DefaultErrorMessages.Extension {
         MAP.put(VOLATILE_ON_VALUE, "'@Volatile' annotation cannot be used on immutable properties");
         MAP.put(VOLATILE_ON_DELEGATE, "'@Volatile' annotation cannot be used on delegated properties");
         MAP.put(SYNCHRONIZED_ON_ABSTRACT, "'@Synchronized' annotation cannot be used on abstract functions");
+        MAP.put(SYNCHRONIZED_ON_INLINE, "'@Synchronized' annotation has no effect on inline functions");
         MAP.put(EXTERNAL_DECLARATION_CANNOT_BE_ABSTRACT, "External declaration can not be abstract");
         MAP.put(EXTERNAL_DECLARATION_CANNOT_HAVE_BODY, "External declaration can not have a body");
         MAP.put(EXTERNAL_DECLARATION_IN_INTERFACE, "Members of interfaces can not be external");

compiler/frontend.java/src/org/jetbrains/kotlin/resolve/jvm/diagnostics/ErrorsJvm.java

@@ -48,6 +48,7 @@ public interface ErrorsJvm {
     DiagnosticFactory0<KtAnnotationEntry> VOLATILE_ON_VALUE = DiagnosticFactory0.create(ERROR);
     DiagnosticFactory0<KtAnnotationEntry> VOLATILE_ON_DELEGATE = DiagnosticFactory0.create(ERROR);
     DiagnosticFactory0<KtAnnotationEntry> SYNCHRONIZED_ON_ABSTRACT = DiagnosticFactory0.create(ERROR);
+    DiagnosticFactory0<KtElement> SYNCHRONIZED_ON_INLINE = DiagnosticFactory0.create(WARNING);
 
     DiagnosticFactory0<KtAnnotationEntry> OVERLOADS_WITHOUT_DEFAULT_ARGUMENTS = DiagnosticFactory0.create(WARNING);
     DiagnosticFactory0<KtAnnotationEntry> OVERLOADS_ABSTRACT = DiagnosticFactory0.create(ERROR);

compiler/frontend.java/src/org/jetbrains/kotlin/resolve/jvm/platform/JvmPlatformConfigurator.kt

@@ -37,7 +37,8 @@ object JvmPlatformConfigurator : PlatformConfiguratorBase(
         ExpectedActualDeclarationChecker(listOf(JavaActualAnnotationArgumentExtractor())),
         JvmAnnotationsTargetNonExistentAccessorChecker(),
         BadInheritedJavaSignaturesChecker,
-        JvmMultifileClassStateChecker
+        JvmMultifileClassStateChecker,
+        SynchronizedOnInlineMethodChecker
     ),
 
     additionalCallCheckers = listOf(

compiler/testData/diagnostics/testsWithStdLib/inline/synchronizedOnInline.kt

@@ -0,0 +1,16 @@
+// !DIAGNOSTICS: -UNUSED_PARAMETER
+
+<!SYNCHRONIZED_ON_INLINE!>@Synchronized<!>
+inline fun foo(f: () -> Unit): Unit = f()
+
+var bar: String
+    <!SYNCHRONIZED_ON_INLINE!>@Synchronized<!>
+    inline get() = ""
+    <!SYNCHRONIZED_ON_INLINE!>@Synchronized<!>
+    inline set(value) {}
+
+inline var baz: String
+    <!SYNCHRONIZED_ON_INLINE!>@Synchronized<!>
+    get() = ""
+    <!SYNCHRONIZED_ON_INLINE!>@Synchronized<!>
+    set(value) {}

compiler/testData/diagnostics/testsWithStdLib/inline/synchronizedOnInline.txt

@@ -0,0 +1,5 @@
+package
+
+@get:kotlin.jvm.Synchronized @set:kotlin.jvm.Synchronized public var bar: kotlin.String
+@get:kotlin.jvm.Synchronized @set:kotlin.jvm.Synchronized public var baz: kotlin.String
+@kotlin.jvm.Synchronized public inline fun foo(/*0*/ f: () -> kotlin.Unit): kotlin.Unit

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

@@ -2736,6 +2736,11 @@ public class DiagnosticsTestWithStdLibGenerated extends AbstractDiagnosticsTestW
         public void testInlineOnlySuppressesNothingToInline() throws Exception {
             runTest("compiler/testData/diagnostics/testsWithStdLib/inline/inlineOnlySuppressesNothingToInline.kt");
         }
+
+        @TestMetadata("synchronizedOnInline.kt")
+        public void testSynchronizedOnInline() throws Exception {
+            runTest("compiler/testData/diagnostics/testsWithStdLib/inline/synchronizedOnInline.kt");
+        }
     }
 
     @TestMetadata("compiler/testData/diagnostics/testsWithStdLib/java")

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

@@ -2736,6 +2736,11 @@ public class DiagnosticsTestWithStdLibUsingJavacGenerated extends AbstractDiagno
         public void testInlineOnlySuppressesNothingToInline() throws Exception {
             runTest("compiler/testData/diagnostics/testsWithStdLib/inline/inlineOnlySuppressesNothingToInline.kt");
         }
+
+        @TestMetadata("synchronizedOnInline.kt")
+        public void testSynchronizedOnInline() throws Exception {
+            runTest("compiler/testData/diagnostics/testsWithStdLib/inline/synchronizedOnInline.kt");
+        }
     }
 
     @TestMetadata("compiler/testData/diagnostics/testsWithStdLib/java")