--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/make/jdk/src/classes/build/tools/taglet/ExtLink.java	Tue Sep 12 19:03:39 2017 +0200
@@ -0,0 +1,109 @@
+/*
+ * Copyright (c) 2017, Oracle and/or its affiliates. All rights reserved.
+ * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
+ *
+ * This code is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License version 2 only, as
+ * published by the Free Software Foundation.  Oracle designates this
+ * particular file as subject to the "Classpath" exception as provided
+ * by Oracle in the LICENSE file that accompanied this code.
+ *
+ * This code is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
+ * version 2 for more details (a copy is included in the LICENSE file that
+ * accompanied this code).
+ *
+ * You should have received a copy of the GNU General Public License version
+ * 2 along with this work; if not, write to the Free Software Foundation,
+ * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
+ *
+ * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
+ * or visit www.oracle.com if you need additional information or have any
+ * questions.
+ */
+
+package build.tools.taglet;
+
+import java.util.EnumSet;
+import java.util.List;
+import java.util.Set;
+import java.util.regex.Matcher;
+import java.util.regex.Pattern;
+import javax.lang.model.element.Element;
+
+import com.sun.source.doctree.DocTree;
+import com.sun.source.doctree.UnknownInlineTagTree;
+import jdk.javadoc.doclet.Taglet;
+
+import static com.sun.source.doctree.DocTree.Kind.*;
+import static jdk.javadoc.doclet.Taglet.Location.*;
+
+/**
+ * An inline tag to conveniently insert an external link.
+ * The tag can be used as follows:
+ * {@extLink name description}, for example
+ * <p>
+ * {@code Please see {@extLink Borealis a spectacular} sight.}
+ * <p>
+ * will produce the following html
+ * <p>
+ * {@code
+ * Please see <a href="https://www.oracle.com/pls/topic/lookup?ctx=javase9&id=Borealis">a spectacular</a> sight.
+ * }
+ */
+public class ExtLink implements Taglet {
+
+    static final String TAG_NAME = "extLink";
+
+    static final String URL = "https://www.oracle.com/pls/topic/lookup?ctx=javase9&amp;id=";
+
+    static final Pattern TAG_PATTERN = Pattern.compile("(?s)(\\s*)(?<name>\\w+)(\\s+)(?<desc>.*)$");
+
+    /**
+     * Returns the set of locations in which the tag may be used.
+     */
+    @Override
+    public Set<Location> getAllowedLocations() {
+        return EnumSet.allOf(jdk.javadoc.doclet.Taglet.Location.class);
+    }
+
+    @Override
+    public boolean isInlineTag() {
+        return true;
+    }
+
+    @Override
+    public String getName() {
+        return TAG_NAME;
+    }
+
+    @Override
+    public String toString(List<? extends DocTree> tags, Element elem) {
+
+        if (tags.isEmpty())
+            return "";
+
+        DocTree tag = tags.get(0);
+        if (tag.getKind() != UNKNOWN_INLINE_TAG)
+            return "";
+
+        UnknownInlineTagTree uitree = (UnknownInlineTagTree) tag;
+        if (uitree.getContent().isEmpty())
+            return "";
+
+        String tagText = uitree.getContent().get(0).toString();
+        Matcher m = TAG_PATTERN.matcher(tagText);
+        if (!m.find())
+            return "";
+
+        StringBuilder sb = new StringBuilder("<a href=\"");
+        sb.append(URL)
+          .append(m.group("name"))
+          .append("\">")
+          .append(m.group("desc"))
+          .append("</a>");
+
+        return sb.toString();
+    }
+}