1 /*
   2  * Copyright (c) 2016, Oracle and/or its affiliates. All rights reserved.
   3  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
   4  *
   5  * This code is free software; you can redistribute it and/or modify it
   6  * under the terms of the GNU General Public License version 2 only, as
   7  * published by the Free Software Foundation.
   8  *
   9  * This code is distributed in the hope that it will be useful, but WITHOUT
  10  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  11  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  12  * version 2 for more details (a copy is included in the LICENSE file that
  13  * accompanied this code).
  14  *
  15  * You should have received a copy of the GNU General Public License version
  16  * 2 along with this work; if not, write to the Free Software Foundation,
  17  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
  18  *
  19  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
  20  * or visit www.oracle.com if you need additional information or have any
  21  * questions.
  22  */
  23 
  24 /**
  25  * JDK-8168373: don't emit conversions for symbols outside their lexical scope
  26  *
  27  * @test
  28  * @run
  29  * @option --language=es6
  30  */
  31 
  32 function p() { return false } // "predicate"
  33 function r(x) { return x } // "read"
  34 
  35 (function() {
  36   try { // Try creates control flow edges from assignments into catch blocks.
  37     // Lexically scoped, never read int variable (undefined at catch block) but still with a cf edge into catch block.
  38     // Since it's never read, it's not written either (Nashorn optimizes some dead writes).
  39     let x = 0;
  40     if (p()) { throw {}; } // We need `p()` so this block doesn't get optimized away, for possibility of a `throw`
  41     x = 0.0; // change the type of x to double
  42     r(x); // read x otherwise it's optimized away
  43   } catch (e) {} // under the bug, "throw" will try to widen unwritten int x to double for here and cause a verifier error
  44 })()