Speed up access to global variables from eval scopes. Traverse the...

test/mjsunit/global-load-from-eval.js

+// Copyright 2009 the V8 project authors. All rights reserved.
+// Redistribution and use in source and binary forms, with or without
+// modification, are permitted provided that the following conditions are
+// met:
+//
+//     * Redistributions of source code must retain the above copyright
+//       notice, this list of conditions and the following disclaimer.
+//     * Redistributions in binary form must reproduce the above
+//       copyright notice, this list of conditions and the following
+//       disclaimer in the documentation and/or other materials provided
+//       with the distribution.
+//     * Neither the name of Google Inc. nor the names of its
+//       contributors may be used to endorse or promote products derived
+//       from this software without specific prior written permission.
+//
+// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+// Tests global loads from eval.
+
+var x = 27;
+
+function test() {
+  function g() {
+    assertEquals(27, eval('x'));
+    function h() {
+      // Shadow with local variable.
+      var x = 22;
+      assertEquals(22, eval('x'));
+      function i(x) {
+        // Shadow with parameter.
+        assertEquals(44, eval('x'));
+        function j() {
+          assertEquals(x, eval('x'));
+          // Shadow with function name.
+          function x() {
+            assertEquals(x, eval('x'));
+          }
+          x();
+        }
+        j();
+      }
+      i(44);
+    }
+    h();
+  }
+  g();
+}
+
+test();
+
+// Test loading of globals from deeply nested eval.  This code is a
+// bit complicated, but the complication is needed to check that the
+// code that loads the global variable accounts for the fact that the
+// global variable becomes shadowed by an eval-introduced variable.
+var result = 0;
+function testDeep(source, load, test) {
+  eval(source);
+  function f() {
+    var y = 23;
+    function g() {
+      var z = 25;
+      function h() {
+        eval(load);
+        eval(test);
+      }
+      h();
+    }
+    g();
+  }
+  f();
+}
+testDeep('1', 'result = x', 'assertEquals(27, result)');
+// Because of the eval-cache, the 'result = x' code gets reused.  This
+// time in a context where the 'x' variable has been shadowed.
+testDeep('var x = 1', 'result = x', 'assertEquals(1, result)');