JVM: Allow the JvmSynthetic annotation on file classes (KT-41884)

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

@@ -42,9 +42,11 @@ import org.jetbrains.org.objectweb.asm.Type;
 
 import java.util.ArrayList;
 import java.util.List;
+import java.util.Objects;
 
 import static org.jetbrains.kotlin.codegen.DescriptorAsmUtil.writeAnnotationData;
 import static org.jetbrains.kotlin.load.java.JvmAnnotationNames.METADATA_PACKAGE_NAME_FIELD_NAME;
+import static org.jetbrains.kotlin.resolve.jvm.annotations.JvmAnnotationUtilKt.JVM_SYNTHETIC_ANNOTATION_FQ_NAME;
 import static org.jetbrains.org.objectweb.asm.Opcodes.*;
 
 public class PackagePartCodegen extends MemberCodegen<KtFile> {
@@ -63,8 +65,20 @@ public class PackagePartCodegen extends MemberCodegen<KtFile> {
 
     @Override
     protected void generateDeclaration() {
+        boolean isSynthetic = false;
+        List<AnnotationDescriptor> fileAnnotationDescriptors = new ArrayList<>();
+        for (KtAnnotationEntry annotationEntry : element.getAnnotationEntries()) {
+            AnnotationDescriptor annotationDescriptor = state.getBindingContext().get(BindingContext.ANNOTATION, annotationEntry);
+            if (annotationDescriptor != null) {
+                fileAnnotationDescriptors.add(annotationDescriptor);
+                if (Objects.equals(annotationDescriptor.getFqName(), JVM_SYNTHETIC_ANNOTATION_FQ_NAME)) {
+                    isSynthetic = true;
+                }
+            }
+        }
+
         v.defineClass(element, state.getClassFileVersion(),
-                      ACC_PUBLIC | ACC_FINAL | ACC_SUPER,
+                      ACC_PUBLIC | ACC_FINAL | ACC_SUPER | (isSynthetic ? ACC_SYNTHETIC : 0),
                       packagePartType.getInternalName(),
                       null,
                       "java/lang/Object",
@@ -74,17 +88,6 @@ public class PackagePartCodegen extends MemberCodegen<KtFile> {
 
         generatePropertyMetadataArrayFieldIfNeeded(packagePartType);
 
-        generateAnnotationsForPartClass();
-    }
-
-    private void generateAnnotationsForPartClass() {
-        List<AnnotationDescriptor> fileAnnotationDescriptors = new ArrayList<>();
-        for (KtAnnotationEntry annotationEntry : element.getAnnotationEntries()) {
-            AnnotationDescriptor annotationDescriptor = state.getBindingContext().get(BindingContext.ANNOTATION, annotationEntry);
-            if (annotationDescriptor != null) {
-                fileAnnotationDescriptors.add(annotationDescriptor);
-            }
-        }
         Annotated annotatedFile = new AnnotatedImpl(Annotations.Companion.create(fileAnnotationDescriptors));
         AnnotationCodegen.forClass(v.getVisitor(), this, state).genAnnotations(annotatedFile, null, null);
     }

compiler/frontend.java/src/org/jetbrains/kotlin/resolve/jvm/annotations/jvmAnnotationUtil.kt

@@ -20,6 +20,8 @@ import org.jetbrains.kotlin.util.findImplementationFromInterface
 val JVM_DEFAULT_FQ_NAME = FqName("kotlin.jvm.JvmDefault")
 val JVM_DEFAULT_NO_COMPATIBILITY_FQ_NAME = FqName("kotlin.jvm.JvmDefaultWithoutCompatibility")
 val JVM_OVERLOADS_FQ_NAME = FqName("kotlin.jvm.JvmOverloads")
+
+@JvmField
 val JVM_SYNTHETIC_ANNOTATION_FQ_NAME = FqName("kotlin.jvm.JvmSynthetic")
 
 @JvmField

compiler/ir/backend.jvm/src/org/jetbrains/kotlin/backend/jvm/codegen/ClassCodegen.kt

@@ -10,8 +10,9 @@ import org.jetbrains.kotlin.backend.jvm.JvmLoweredDeclarationOrigin
 import org.jetbrains.kotlin.backend.jvm.lower.MultifileFacadeFileEntry
 import org.jetbrains.kotlin.backend.jvm.lower.buildAssertionsDisabledField
 import org.jetbrains.kotlin.backend.jvm.lower.hasAssertionsDisabledField
-import org.jetbrains.kotlin.codegen.*
+import org.jetbrains.kotlin.codegen.DescriptorAsmUtil
 import org.jetbrains.kotlin.codegen.inline.*
+import org.jetbrains.kotlin.codegen.writeKotlinMetadata
 import org.jetbrains.kotlin.config.LanguageFeature
 import org.jetbrains.kotlin.config.LanguageVersionSettings
 import org.jetbrains.kotlin.descriptors.DescriptorVisibilities
@@ -446,6 +447,7 @@ class ClassCodegen private constructor(
 private val IrClass.flags: Int
     get() = origin.flags or getVisibilityAccessFlagForClass() or
             (if (isAnnotatedWithDeprecated) Opcodes.ACC_DEPRECATED else 0) or
+            (if (hasAnnotation(JVM_SYNTHETIC_ANNOTATION_FQ_NAME)) Opcodes.ACC_SYNTHETIC else 0) or
             when {
                 isAnnotationClass -> Opcodes.ACC_ANNOTATION or Opcodes.ACC_INTERFACE or Opcodes.ACC_ABSTRACT
                 isInterface -> Opcodes.ACC_INTERFACE or Opcodes.ACC_ABSTRACT

compiler/testData/writeFlags/class/accessFlags/syntheticFile.kt

@@ -0,0 +1,10 @@
+// WITH_RUNTIME
+// FILE: test.kt
+@file:Suppress("WRONG_ANNOTATION_TARGET_WITH_USE_SITE_TARGET")
+@file:JvmSynthetic
+
+private val keepme = 1
+
+// TESTED_OBJECT_KIND: class
+// TESTED_OBJECTS: TestKt
+// FLAGS: ACC_FINAL, ACC_PUBLIC, ACC_SUPER, ACC_SYNTHETIC

compiler/tests/org/jetbrains/kotlin/codegen/flags/WriteFlagsTestGenerated.java

@@ -153,6 +153,11 @@ public class WriteFlagsTestGenerated extends AbstractWriteFlagsTest {
             public void testSimpleFilePackageFacade() throws Exception {
                 runTest("compiler/testData/writeFlags/class/accessFlags/simpleFilePackageFacade.kt");
             }
+
+            @TestMetadata("syntheticFile.kt")
+            public void testSyntheticFile() throws Exception {
+                runTest("compiler/testData/writeFlags/class/accessFlags/syntheticFile.kt");
+            }
         }
 
         @TestMetadata("compiler/testData/writeFlags/class/deprecatedFlag")

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

@@ -153,6 +153,11 @@ public class IrWriteFlagsTestGenerated extends AbstractIrWriteFlagsTest {
             public void testSimpleFilePackageFacade() throws Exception {
                 runTest("compiler/testData/writeFlags/class/accessFlags/simpleFilePackageFacade.kt");
             }
+
+            @TestMetadata("syntheticFile.kt")
+            public void testSyntheticFile() throws Exception {
+                runTest("compiler/testData/writeFlags/class/accessFlags/syntheticFile.kt");
+            }
         }
 
         @TestMetadata("compiler/testData/writeFlags/class/deprecatedFlag")