Remove KotlinClassFileHeader.HeaderType.NONE

Use null instead

compiler/cli/src/org/jetbrains/jet/cli/jvm/compiler/CliVirtualFileFinder.java

@@ -20,7 +20,6 @@ import com.intellij.openapi.vfs.VirtualFile;
 import com.intellij.psi.search.GlobalSearchScope;
 import org.jetbrains.annotations.NotNull;
 import org.jetbrains.annotations.Nullable;
-import org.jetbrains.jet.cli.jvm.compiler.ClassPath;
 import org.jetbrains.jet.lang.resolve.java.resolver.KotlinClassFileHeader;
 import org.jetbrains.jet.lang.resolve.java.vfilefinder.VirtualFileFinder;
 import org.jetbrains.jet.lang.resolve.name.FqName;
@@ -80,7 +79,7 @@ public class CliVirtualFileFinder implements VirtualFileFinder {
                 return null;
             }
             //NOTE: currently we use VirtualFileFinder to find Kotlin binaries only
-            if (KotlinClassFileHeader.readKotlinHeaderFromClassFile(vFile).getType() != KotlinClassFileHeader.HeaderType.NONE) {
+            if (KotlinClassFileHeader.readKotlinHeaderFromClassFile(vFile).getType() != null) {
                 return vFile;
             }
         }

core/descriptor.loader.java/src/org/jetbrains/jet/lang/resolve/java/resolver/DeserializedDescriptorResolver.java

@@ -127,7 +127,7 @@ public final class DeserializedDescriptorResolver {
     private String[] readData(@NotNull VirtualFile virtualFile) {
         KotlinClassFileHeader header = KotlinClassFileHeader.readKotlinHeaderFromClassFile(virtualFile);
         int version = header.getVersion();
-        if (!isAbiVersionCompatible(version) && header.getType() != KotlinClassFileHeader.HeaderType.NONE) {
+        if (!isAbiVersionCompatible(version) && header.getType() != null) {
             errorReporter.reportIncompatibleAbiVersion(header.getFqName(), virtualFile, version);
             return null;
         }

core/descriptor.loader.java/src/org/jetbrains/jet/lang/resolve/java/resolver/KotlinClassFileHeader.java

@@ -42,8 +42,7 @@ public final class KotlinClassFileHeader {
         CLASS(JvmAnnotationNames.KOTLIN_CLASS),
         PACKAGE(JvmAnnotationNames.KOTLIN_PACKAGE),
         OLD_CLASS(JvmAnnotationNames.OLD_JET_CLASS_ANNOTATION),
-        OLD_PACKAGE(JvmAnnotationNames.OLD_JET_PACKAGE_CLASS_ANNOTATION),
+        OLD_PACKAGE(JvmAnnotationNames.OLD_JET_PACKAGE_CLASS_ANNOTATION);
-        NONE(null);
 
         @Nullable
         private final JvmClassName correspondingAnnotation;
@@ -56,7 +55,7 @@ public final class KotlinClassFileHeader {
             return this == CLASS || this == PACKAGE;
         }
 
-        @NotNull
+        @Nullable
         private static HeaderType byDescriptor(@NotNull String desc) {
             for (HeaderType headerType : HeaderType.values()) {
                 JvmClassName annotation = headerType.correspondingAnnotation;
@@ -67,7 +66,7 @@ public final class KotlinClassFileHeader {
                     return headerType;
                 }
             }
-            return NONE;
+            return null;
         }
     }
 
@@ -75,8 +74,8 @@ public final class KotlinClassFileHeader {
 
     @Nullable
     private String[] annotationData = null;
-    @NotNull
+    @Nullable
-    private HeaderType type = HeaderType.NONE;
+    private HeaderType type = null;
     @Nullable
     private JvmClassName jvmClassName = null;
 
@@ -84,7 +83,7 @@ public final class KotlinClassFileHeader {
         return version;
     }
 
-    @NotNull
+    @Nullable
     public HeaderType getType() {
         return type;
     }
@@ -93,7 +92,7 @@ public final class KotlinClassFileHeader {
      * @return true if this is a header for compiled Kotlin file with correct abi version which can be processed by compiler or the IDE
      */
     public boolean isCompatibleKotlinCompiledFile() {
-        return type.isValidAnnotation() && isAbiVersionCompatible(version);
+        return type != null && type.isValidAnnotation() && isAbiVersionCompatible(version);
     }
 
     /**
@@ -107,7 +106,7 @@ public final class KotlinClassFileHeader {
 
     @Nullable
     public String[] getAnnotationData() {
-        if (annotationData == null && type != HeaderType.NONE) {
+        if (annotationData == null && type != null) {
             LOG.error("Data for annotations " + type.correspondingAnnotation + " was not read.");
         }
         return annotationData;
@@ -127,14 +126,15 @@ public final class KotlinClassFileHeader {
         @Override
         public AnnotationVisitor visitAnnotation(final String desc, boolean visible) {
             HeaderType headerTypeByAnnotation = HeaderType.byDescriptor(desc);
-            if (headerTypeByAnnotation == HeaderType.NONE) {
+            if (headerTypeByAnnotation == null) {
                 return null;
             }
-            if (headerTypeByAnnotation.isValidAnnotation() && type.isValidAnnotation()) {
+            boolean alreadyFoundValid = type != null && type.isValidAnnotation();
+            if (headerTypeByAnnotation.isValidAnnotation() && alreadyFoundValid) {
                 throw new IllegalStateException("Both " + type.correspondingAnnotation + " and "
                                                  + headerTypeByAnnotation.correspondingAnnotation + " present!");
             }
-            if (!type.isValidAnnotation()) {
+            if (!alreadyFoundValid) {
                 type = headerTypeByAnnotation;
             }
             if (!headerTypeByAnnotation.isValidAnnotation()) {