diff -r 000000000000 -r 959103a6100f test/tools/javac/7142086/T7142086.java
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/test/tools/javac/7142086/T7142086.java	Wed Apr 27 01:34:52 2016 +0800
@@ -0,0 +1,115 @@
+/*
+ * Copyright (c) 2012, 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.
+ *
+ * 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.
+ */
+
+/*
+ * @test
+ * @bug 7142086
+ * @summary performance problem in Check.checkOverrideClashes(...)
+ * @run main/timeout=10 T7142086
+ */
+
+import com.sun.source.util.JavacTask;
+import java.net.URI;
+import java.util.List;
+import java.util.ArrayList;
+import java.util.Locale;
+import javax.tools.Diagnostic;
+import javax.tools.JavaCompiler;
+import javax.tools.JavaFileObject;
+import javax.tools.SimpleJavaFileObject;
+import javax.tools.StandardJavaFileManager;
+import javax.tools.ToolProvider;
+
+public class T7142086 {
+
+    final static int N_METHODS = 1000;
+
+    static class TestClass extends SimpleJavaFileObject {
+
+        String methTemplate = "abstract void m(A#N p);";
+        String classTemplate = "abstract class Test { #M }";
+
+        String source;
+
+        public TestClass() {
+            super(URI.create("myfo:/Test.java"), JavaFileObject.Kind.SOURCE);
+            StringBuilder buf = new StringBuilder();
+            for (int i = 0 ; i < N_METHODS ; i++) {
+                buf.append(methTemplate.replace("#N", String.valueOf(i)));
+                buf.append("\n");
+            }
+            source = classTemplate.replace("#M", buf.toString());
+        }
+
+        @Override
+        public CharSequence getCharContent(boolean ignoreEncodingErrors) {
+            return source;
+        }
+    }
+
+    static class AnSource extends SimpleJavaFileObject {
+
+        String classTemplate = "abstract class A#N { }";
+
+        String source;
+
+        public AnSource(int n) {
+            super(URI.create("myfo:/Test.java"), JavaFileObject.Kind.SOURCE);
+            source = classTemplate.replace("#N", String.valueOf(n));
+        }
+
+        @Override
+        public CharSequence getCharContent(boolean ignoreEncodingErrors) {
+            return source;
+        }
+    }
+
+    public static void main(String... args) throws Exception {
+        ArrayList<JavaFileObject> sources = new ArrayList<>();
+        for (int i = 0 ; i < N_METHODS ; i++) {
+            sources.add(new AnSource(i));
+        }
+        sources.add(new TestClass());
+        new T7142086().run(sources);
+    }
+
+    void run(List<JavaFileObject> sources) throws Exception {
+        DiagnosticChecker dc = new DiagnosticChecker();
+        JavaCompiler comp = ToolProvider.getSystemJavaCompiler();
+        StandardJavaFileManager fm = comp.getStandardFileManager(null, null, null);
+        JavacTask ct = (JavacTask)comp.getTask(null, fm, dc,
+                null, null, sources);
+        ct.analyze();
+    }
+
+    static class DiagnosticChecker implements javax.tools.DiagnosticListener<JavaFileObject> {
+
+        boolean errorFound;
+
+        public void report(Diagnostic<? extends JavaFileObject> diagnostic) {
+            if (diagnostic.getKind() == Diagnostic.Kind.ERROR) {
+                throw new AssertionError("unexpected diagnostic: " + diagnostic.getMessage(Locale.getDefault()));
+            }
+        }
+    }
+}