diff -r 141f584faf59 -r 001f73134346 langtools/make/src/classes/build/tools/symbolgenerator/TransitiveDependencies.java
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/langtools/make/src/classes/build/tools/symbolgenerator/TransitiveDependencies.java	Fri May 12 06:42:37 2017 +0200
@@ -0,0 +1,103 @@
+/*
+ * 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.symbolgenerator;
+
+import java.io.IOException;
+import java.util.Arrays;
+import java.util.HashSet;
+import java.util.LinkedList;
+import java.util.List;
+import java.util.Set;
+import java.util.stream.Collectors;
+
+import javax.lang.model.element.ModuleElement.RequiresDirective;
+import javax.lang.model.util.Elements;
+import javax.tools.JavaCompiler;
+import javax.tools.ToolProvider;
+
+import com.sun.tools.javac.api.JavacTaskImpl;
+import com.sun.tools.javac.code.Symbol.ModuleSymbol;
+
+/**
+ * Print reflexive transitive closure of the given modules along their requires transitive edges.
+ */
+public class TransitiveDependencies {
+
+    private static void help() {
+        System.err.println("java TransitiveDependencies <module-source-path> <root-modules>");
+    }
+
+    public static void main(String... args) throws IOException {
+        if (args.length < 1) {
+            help();
+            return ;
+        }
+
+        JavaCompiler compiler = ToolProvider.getSystemJavaCompiler();
+        List<String> options = Arrays.asList("-source", "9",
+                                             "-target", "9",
+                                             "--system", "none",
+                                             "--module-source-path", args[0],
+                                             "--add-modules", Arrays.stream(args)
+                                                                    .skip(1)
+                                                                    .collect(Collectors.joining(",")));
+        List<String> jlObjectList = Arrays.asList("java.lang.Object");
+        JavacTaskImpl task = (JavacTaskImpl) compiler.getTask(null, null, d -> {}, options, jlObjectList, null);
+        task.enter();
+        Elements elements = task.getElements();
+        List<String> todo = new LinkedList<>();
+        Arrays.stream(args).skip(1).forEach(todo::add);
+        Set<String> allModules = new HashSet<>();
+
+        while (!todo.isEmpty()) {
+            String current = todo.remove(0);
+
+            if (!allModules.add(current))
+                continue;
+
+            ModuleSymbol mod = (ModuleSymbol) elements.getModuleElement(current);
+
+            if (mod == null) {
+                throw new IllegalStateException("Missing: " + current);
+            }
+
+             //use the internal structure to avoid unnecesarily completing the symbol using the UsesProvidesVisitor:
+            for (RequiresDirective rd : mod.requires) {
+                if (rd.isTransitive()) {
+                    todo.add(rd.getDependency().getQualifiedName().toString());
+                }
+            }
+        }
+
+        allModules.add("java.base");
+        allModules.add("jdk.unsupported");
+
+        allModules.stream()
+                  .sorted()
+                  .forEach(System.out::println);
+    }
+
+}