Fix handling of const initialization. We did not handle the fact that...

test/mjsunit/const-eval-init.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:
+//
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+//     * Redistributions in binary form must reproduce the above
+//       copyright notice, this list of conditions and the following
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+//       with the distribution.
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+//       contributors may be used to endorse or promote products derived
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+//
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+// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
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+// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+// Test the handling of initialization of deleted const variables.
+// This only makes sense in local scopes since the declaration and
+// initialization of consts in the global scope happen at the same
+// time.
+
+function testIntroduceGlobal() {
+  var source =
+      // Deleting 'x' removes the local const property.
+      "delete x;" +
+      // Initialization turns into assignment to global 'x'.
+      "const x = 3; assertEquals(3, x);" +
+      // No constness of the global 'x'.
+      "x = 4; assertEquals(4, x);";
+  eval(source);
+}
+
+testIntroduceGlobal();
+assertEquals(4, x);
+
+function testAssignExistingGlobal() {
+  var source =
+      // Delete 'x' to remove the local const property.
+      "delete x;" +
+      // Initialization turns into assignment to global 'x'.
+      "const x = 5; assertEquals(5, x);" +
+      // No constness of the global 'x'.
+      "x = 6; assertEquals(6, x);";
+  eval(source);
+}
+
+testAssignExistingGlobal();
+assertEquals(6, x);
+
+function testAssignmentArgument(x) {
+  function local() {
+    var source = "delete x; const x = 7; assertEquals(7, x)";
+    eval(source);
+  }
+  local();
+  assertEquals(7, x);
+}
+
+testAssignmentArgument();
+assertEquals(6, x);
+
+__defineSetter__('x', function() { throw 42; });
+function testAssignGlobalThrows() {
+  // Initialization turns into assignment to global 'x' which
+  // throws an exception.
+  var source = "delete x; const x = 8";
+  eval(source);
+}
+
+assertThrows("testAssignGlobalThrows()");
+
+function testInitFastCaseExtension() {
+  var source = "const x = 9; assertEquals(9, x); x = 10; assertEquals(9, x)";
+  eval(source);
+}
+
+testInitFastCaseExtension();
+
+function testInitSlowCaseExtension() {
+  var source = "";
+  // Introduce 100 properties on the context extension object to force
+  // it in slow case.
+  for (var i = 0; i < 100; i++) source += ("var a" + i + " = i;");
+  source += "const x = 10; assertEquals(10, x); x = 11; assertEquals(10, x)";
+  eval(source);
+}
+
+testInitSlowCaseExtension();
+
+function testAssignSurroundingContextSlot() {
+  var x = 12;
+  function local() {
+    var source = "delete x; const x = 13; assertEquals(13, x)";
+    eval(source);
+  }
+  local();
+  assertEquals(13, x);
+}
+
+testAssignSurroundingContextSlot();