--- old/src/java.base/share/classes/jdk/internal/org/objectweb/asm/util/CheckClassAdapter.java	Fri Oct 27 09:24:51 2017
+++ new/src/java.base/share/classes/jdk/internal/org/objectweb/asm/util/CheckClassAdapter.java	Fri Oct 27 09:24:50 2017
@@ -73,6 +73,7 @@
 import jdk.internal.org.objectweb.asm.FieldVisitor;
 import jdk.internal.org.objectweb.asm.Label;
 import jdk.internal.org.objectweb.asm.MethodVisitor;
+import jdk.internal.org.objectweb.asm.ModuleVisitor;
 import jdk.internal.org.objectweb.asm.Opcodes;
 import jdk.internal.org.objectweb.asm.Type;
 import jdk.internal.org.objectweb.asm.TypePath;
@@ -181,6 +182,11 @@
     private boolean end;
 
     /**
+     * <tt>true</tt> if the visitModule method has been called.
+     */
+    private boolean module;
+
+    /**
      * The already visited labels. This map associate Integer values to Label
      * keys.
      */
@@ -363,7 +369,7 @@
      *             If a subclass calls this constructor.
      */
     public CheckClassAdapter(final ClassVisitor cv, final boolean checkDataFlow) {
-        this(Opcodes.ASM5, cv, checkDataFlow);
+        this(Opcodes.ASM6, cv, checkDataFlow);
         if (getClass() != CheckClassAdapter.class) {
             throw new IllegalStateException();
         }
@@ -374,7 +380,7 @@
      *
      * @param api
      *            the ASM API version implemented by this visitor. Must be one
-     *            of {@link Opcodes#ASM4} or {@link Opcodes#ASM5}.
+     *            of {@link Opcodes#ASM4}, {@link Opcodes#ASM5} or {@link Opcodes#ASM6}.
      * @param cv
      *            the class visitor to which this adapter must delegate calls.
      * @param checkDataFlow
@@ -407,8 +413,12 @@
                 + Opcodes.ACC_SUPER + Opcodes.ACC_INTERFACE
                 + Opcodes.ACC_ABSTRACT + Opcodes.ACC_SYNTHETIC
                 + Opcodes.ACC_ANNOTATION + Opcodes.ACC_ENUM
-                + Opcodes.ACC_DEPRECATED + 0x40000); // ClassWriter.ACC_SYNTHETIC_ATTRIBUTE
-        if (name == null || !name.endsWith("package-info")) {
+                + Opcodes.ACC_DEPRECATED + Opcodes.ACC_MODULE
+                + 0x40000); // ClassWriter.ACC_SYNTHETIC_ATTRIBUTE
+        if (name == null) {
+            throw new IllegalArgumentException("Illegal class name (null)");
+        }
+        if (!name.endsWith("package-info")) {
             CheckMethodAdapter.checkInternalName(name, "class name");
         }
         if ("java/lang/Object".equals(name)) {
@@ -449,6 +459,22 @@
         super.visitSource(file, debug);
     }
 
+    @Override
+    public ModuleVisitor visitModule(String name, int access, String version) {
+        checkState();
+        if (module) {
+            throw new IllegalStateException(
+                    "visitModule can be called only once.");
+        }
+        module = true;
+        if (name == null) {
+            throw new IllegalArgumentException("Illegal module name (null)");
+        }
+        checkAccess(access, Opcodes.ACC_OPEN | Opcodes.ACC_SYNTHETIC);
+        return new CheckModuleAdapter(super.visitModule(name, access, version),
+            (access & Opcodes.ACC_OPEN) != 0);
+    }
+
     @Override
     public void visitOuterClass(final String owner, final String name,
             final String desc) {