visitAnnotation() could return null for light classes

annotations/org/jetbrains/asm4/annotations.xml

@@ -0,0 +1,18 @@
+<root>
+  <item name='org.jetbrains.asm4.ClassVisitor org.jetbrains.asm4.AnnotationVisitor visitAnnotation(java.lang.String, boolean)'>
+    <annotation name='org.jetbrains.annotations.Nullable'/>
+  </item>
+  <item name='org.jetbrains.asm4.FieldVisitor org.jetbrains.asm4.AnnotationVisitor visitAnnotation(java.lang.String, boolean)'>
+    <annotation name='org.jetbrains.annotations.Nullable'/>
+  </item>
+  <item name='org.jetbrains.asm4.MethodVisitor org.jetbrains.asm4.AnnotationVisitor visitAnnotation(java.lang.String, boolean)'>
+    <annotation name='org.jetbrains.annotations.Nullable'/>
+  </item>
+  <item name='org.jetbrains.asm4.MethodVisitor org.jetbrains.asm4.AnnotationVisitor visitAnnotationDefault()'>
+    <annotation name='org.jetbrains.annotations.Nullable'/>
+  </item>
+  <item
+      name='org.jetbrains.asm4.MethodVisitor org.jetbrains.asm4.AnnotationVisitor visitParameterAnnotation(int, java.lang.String, boolean)'>
+    <annotation name='org.jetbrains.annotations.Nullable'/>
+  </item>
+</root>

compiler/backend/src/org/jetbrains/jet/codegen/AnnotationCodegen.java

@@ -42,6 +42,8 @@ import java.util.*;
 import static org.jetbrains.jet.lang.resolve.BindingContextUtils.descriptorToDeclaration;
 
 public abstract class AnnotationCodegen {
+    private static final AnnotationVisitor NO_ANNOTATION_VISITOR = new AnnotationVisitor(Opcodes.ASM4) {};
+
     private final JetTypeMapper typeMapper;
     private final BindingContext bindingContext;
 
@@ -271,50 +273,61 @@ public abstract class AnnotationCodegen {
         return RetentionPolicy.CLASS;
     }
 
+    @NotNull
     abstract AnnotationVisitor visitAnnotation(String descr, boolean visible);
 
     public static AnnotationCodegen forClass(final ClassVisitor cv, JetTypeMapper mapper) {
         return new AnnotationCodegen(mapper) {
+            @NotNull
             @Override
             AnnotationVisitor visitAnnotation(String descr, boolean visible) {
-                return cv.visitAnnotation(descr, visible);
+                return safe(cv.visitAnnotation(descr, visible));
             }
         };
     }
 
     public static AnnotationCodegen forMethod(final MethodVisitor mv, JetTypeMapper mapper) {
         return new AnnotationCodegen(mapper) {
+            @NotNull
             @Override
             AnnotationVisitor visitAnnotation(String descr, boolean visible) {
-                return mv.visitAnnotation(descr, visible);
+                return safe(mv.visitAnnotation(descr, visible));
             }
         };
     }
 
     public static AnnotationCodegen forField(final FieldVisitor fv, JetTypeMapper mapper) {
         return new AnnotationCodegen(mapper) {
+            @NotNull
             @Override
             AnnotationVisitor visitAnnotation(String descr, boolean visible) {
-                return fv.visitAnnotation(descr, visible);
+                return safe(fv.visitAnnotation(descr, visible));
             }
         };
     }
 
     public static AnnotationCodegen forParameter(final int parameter, final MethodVisitor mv, JetTypeMapper mapper) {
         return new AnnotationCodegen(mapper) {
+            @NotNull
             @Override
             AnnotationVisitor visitAnnotation(String descr, boolean visible) {
-                return mv.visitParameterAnnotation(parameter, descr, visible);
+                return safe(mv.visitParameterAnnotation(parameter, descr, visible));
             }
         };
     }
 
     public static AnnotationCodegen forAnnotationDefaultValue(final MethodVisitor mv, JetTypeMapper mapper) {
         return new AnnotationCodegen(mapper) {
+            @NotNull
             @Override
             AnnotationVisitor visitAnnotation(String descr, boolean visible) {
-                return mv.visitAnnotationDefault();
+                return safe(mv.visitAnnotationDefault());
             }
         };
     }
+
+    @NotNull
+    private static AnnotationVisitor safe(@Nullable AnnotationVisitor av) {
+        return av == null ? NO_ANNOTATION_VISITOR : av;
+    }
 }

compiler/backend/src/org/jetbrains/jet/codegen/FunctionCodegen.java

@@ -203,11 +203,13 @@ public class FunctionCodegen extends ParentCodegenAwareImpl {
 
             AnnotationVisitor av =
                     mv.visitParameterAnnotation(i, asmDescByFqNameWithoutInnerClasses(fqNameByClass(JetValueParameter.class)), true);
-            av.visit("name", name);
+            if (av != null) {
-            if (nullableType) {
+                av.visit("name", name);
-                av.visit("type", "?");
+                if (nullableType) {
+                    av.visit("type", "?");
+                }
+                av.visitEnd();
             }
-            av.visitEnd();
         }
     }
 
@@ -219,7 +221,9 @@ public class FunctionCodegen extends ParentCodegenAwareImpl {
         // see MethodWriter.visitParameterAnnotation()
 
         AnnotationVisitor av = mv.visitParameterAnnotation(i, "Ljava/lang/Synthetic;", true);
-        av.visitEnd();
+        if (av != null) {
+            av.visitEnd();
+        }
     }
 
     @Nullable

compiler/testData/asJava/nullabilityAnnotations/Synthetic.java

@@ -0,0 +1,15 @@
+public final class Synthetic implements jet.JetObject {
+    @org.jetbrains.annotations.NotNull
+    private final void foo() { /* compiled code */ }
+
+    @org.jetbrains.annotations.NotNull
+    public Synthetic() { /* compiled code */ }
+
+    public final class Inner implements jet.JetObject {
+        @org.jetbrains.annotations.NotNull
+        public final void test() { /* compiled code */ }
+
+        @org.jetbrains.annotations.NotNull
+        public Inner() { /* compiled code */ }
+    }
+}

compiler/testData/asJava/nullabilityAnnotations/Synthetic.kt

@@ -0,0 +1,9 @@
+class Synthetic {
+    inner class Inner {
+        fun test() {
+            foo()
+        }
+    }
+
+    private fun foo() {}
+}

compiler/tests/org/jetbrains/jet/asJava/NullabilityAnnotationsTest.java

@@ -61,6 +61,10 @@ public class NullabilityAnnotationsTest extends KotlinAsJavaTestBase {
         doTest(getTestName(false));
     }
 
+    public void testSynthetic() throws Exception {
+        doTest(getTestName(false));
+    }
+
     private void doTest(@NotNull String fqName) {
         PsiClass psiClass = finder.findClass(fqName, GlobalSearchScope.allScope(getProject()));
         if (!(psiClass instanceof KotlinLightClass)) {