Class : Implement getSimpleName for inner classes using dex annotations.

Also, implement isMemberClass in terms of getDeclaringClass. This allows
us to get rid of the (confusing and easy to abuse, IMO)
getSimpleBinaryName helper.

bug: 28800927

Change-Id: I6759e0abe360a14f2f874f302108a1beb352b7d0

ojluni/src/main/java/java/lang/Class.java

@@ -1156,41 +1156,26 @@ public final
         if (isArray())
             return getComponentType().getSimpleName()+"[]";
 
-        String simpleName = getSimpleBinaryName();
-        if (simpleName == null) { // top level class
-            simpleName = getName();
-            return simpleName.substring(simpleName.lastIndexOf(".")+1); // strip the package name
+        if (isAnonymousClass()) {
+            return "";
         }
-        // According to JLS3 "Binary Compatibility" (13.1) the binary
-        // name of non-package classes (not top level) is the binary
-        // name of the immediately enclosing class followed by a '$' followed by:
-        // (for nested and inner classes): the simple name.
-        // (for local classes): 1 or more digits followed by the simple name.
-        // (for anonymous classes): 1 or more digits.
 
-        // Since getSimpleBinaryName() will strip the binary name of
-        // the immediatly enclosing class, we are now looking at a
-        // string that matches the regular expression "\$[0-9]*"
-        // followed by a simple name (considering the simple of an
-        // anonymous class to be the empty string).
+        if (isMemberClass() || isLocalClass()) {
+            // Note that we obtain this information from getInnerClassName(), which uses
+            // dex system annotations to obtain the name. It is possible for this information
+            // to disagree with the actual enclosing class name. For example, if dex
+            // manipulation tools have renamed the enclosing class without adjusting
+            // the system annotation to match. See http://b/28800927.
+            return getInnerClassName();
+        }
 
-        // Remove leading "\$[0-9]*" from the name
-        int length = simpleName.length();
-        if (length < 1 || simpleName.charAt(0) != '$')
-            throw new InternalError("Malformed class name");
-        int index = 1;
-        while (index < length && isAsciiDigit(simpleName.charAt(index)))
-            index++;
-        // Eventually, this is the empty string iff this is an anonymous class
-        return simpleName.substring(index);
-    }
+        String simpleName = getName();
+        final int dot = simpleName.lastIndexOf(".");
+        if (dot > 0) {
+            return simpleName.substring(simpleName.lastIndexOf(".")+1); // strip the package name
+        }
 
-    /**
-     * Character.isDigit answers {@code true} to some non-ascii
-     * digits.  This one does not.
-     */
-    private static boolean isAsciiDigit(char c) {
-        return '0' <= c && c <= '9';
+        return simpleName;
     }
 
     /**
@@ -1253,25 +1238,7 @@ public final
      * @since 1.5
      */
     public boolean isMemberClass() {
-        return getSimpleBinaryName() != null && !isLocalOrAnonymousClass();
-    }
-
-    /**
-     * Returns the "simple binary name" of the underlying class, i.e.,
-     * the binary name without the leading enclosing class name.
-     * Returns {@code null} if the underlying class is a top level
-     * class.
-     */
-    private String getSimpleBinaryName() {
-        Class<?> enclosingClass = getEnclosingClass();
-        if (enclosingClass == null) // top level class
-            return null;
-        // Otherwise, strip the enclosing class' name
-        try {
-            return getName().substring(enclosingClass.getName().length());
-        } catch (IndexOutOfBoundsException ex) {
-            throw new InternalError("Malformed class name");
-        }
+        return getDeclaringClass() != null;
     }
 
     /**