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      <base href="https://bugs.webkit.org/" />
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    <body><table border="1" cellspacing="0" cellpadding="8">
        <tr>
          <th>Bug ID</th>
          <td><a class="bz_bug_link 
          bz_status_NEW "
   title="NEW - [ES6] Support Reflect.construct"
   href="https://bugs.webkit.org/show_bug.cgi?id=147330">147330</a>
          </td>
        </tr>

        <tr>
          <th>Summary</th>
          <td>[ES6] Support Reflect.construct
          </td>
        </tr>

        <tr>
          <th>Classification</th>
          <td>Unclassified
          </td>
        </tr>

        <tr>
          <th>Product</th>
          <td>WebKit
          </td>
        </tr>

        <tr>
          <th>Version</th>
          <td>528+ (Nightly build)
          </td>
        </tr>

        <tr>
          <th>Hardware</th>
          <td>Unspecified
          </td>
        </tr>

        <tr>
          <th>OS</th>
          <td>Unspecified
          </td>
        </tr>

        <tr>
          <th>Status</th>
          <td>NEW
          </td>
        </tr>

        <tr>
          <th>Severity</th>
          <td>Normal
          </td>
        </tr>

        <tr>
          <th>Priority</th>
          <td>P2
          </td>
        </tr>

        <tr>
          <th>Component</th>
          <td>JavaScriptCore
          </td>
        </tr>

        <tr>
          <th>Assignee</th>
          <td>webkit-unassigned&#64;lists.webkit.org
          </td>
        </tr>

        <tr>
          <th>Reporter</th>
          <td>utatane.tea&#64;gmail.com
          </td>
        </tr></table>
      <p>
        <div>
        <pre>Reflect.construct has the crazy part in the spec.
It can replace the `newTarget` dynamically.
Since the current JSC has an assumption that `newTarget` is fixed when the derived constructor is defined, it breaks this assumption.

For example,

Reflect.construct(function () { }, [], Map)

does not work (breaks in LLInt layer) because the byte code op_create_this assumes that the newTarget is always the JSFunction (not InternalFunction).

I think Reflect.construct is the only place where we can replace the newTarget dynamically.
So the easiest way to implement it is adding a special (slow) path to Reflect.construct.</pre>
        </div>
      </p>
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