<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.1//EN"
"http://www.w3.org/TR/xhtml11/DTD/xhtml11.dtd">
<html xmlns="http://www.w3.org/1999/xhtml">
<head><meta http-equiv="content-type" content="text/html; charset=utf-8" />
<title>[197155] trunk/Source/JavaScriptCore</title>
</head>
<body>
<style type="text/css"><!--
#msg dl.meta { border: 1px #006 solid; background: #369; padding: 6px; color: #fff; }
#msg dl.meta dt { float: left; width: 6em; font-weight: bold; }
#msg dt:after { content:':';}
#msg dl, #msg dt, #msg ul, #msg li, #header, #footer, #logmsg { font-family: verdana,arial,helvetica,sans-serif; font-size: 10pt; }
#msg dl a { font-weight: bold}
#msg dl a:link { color:#fc3; }
#msg dl a:active { color:#ff0; }
#msg dl a:visited { color:#cc6; }
h3 { font-family: verdana,arial,helvetica,sans-serif; font-size: 10pt; font-weight: bold; }
#msg pre { overflow: auto; background: #ffc; border: 1px #fa0 solid; padding: 6px; }
#logmsg { background: #ffc; border: 1px #fa0 solid; padding: 1em 1em 0 1em; }
#logmsg p, #logmsg pre, #logmsg blockquote { margin: 0 0 1em 0; }
#logmsg p, #logmsg li, #logmsg dt, #logmsg dd { line-height: 14pt; }
#logmsg h1, #logmsg h2, #logmsg h3, #logmsg h4, #logmsg h5, #logmsg h6 { margin: .5em 0; }
#logmsg h1:first-child, #logmsg h2:first-child, #logmsg h3:first-child, #logmsg h4:first-child, #logmsg h5:first-child, #logmsg h6:first-child { margin-top: 0; }
#logmsg ul, #logmsg ol { padding: 0; list-style-position: inside; margin: 0 0 0 1em; }
#logmsg ul { text-indent: -1em; padding-left: 1em; }#logmsg ol { text-indent: -1.5em; padding-left: 1.5em; }
#logmsg > ul, #logmsg > ol { margin: 0 0 1em 0; }
#logmsg pre { background: #eee; padding: 1em; }
#logmsg blockquote { border: 1px solid #fa0; border-left-width: 10px; padding: 1em 1em 0 1em; background: white;}
#logmsg dl { margin: 0; }
#logmsg dt { font-weight: bold; }
#logmsg dd { margin: 0; padding: 0 0 0.5em 0; }
#logmsg dd:before { content:'\00bb';}
#logmsg table { border-spacing: 0px; border-collapse: collapse; border-top: 4px solid #fa0; border-bottom: 1px solid #fa0; background: #fff; }
#logmsg table th { text-align: left; font-weight: normal; padding: 0.2em 0.5em; border-top: 1px dotted #fa0; }
#logmsg table td { text-align: right; border-top: 1px dotted #fa0; padding: 0.2em 0.5em; }
#logmsg table thead th { text-align: center; border-bottom: 1px solid #fa0; }
#logmsg table th.Corner { text-align: left; }
#logmsg hr { border: none 0; border-top: 2px dashed #fa0; height: 1px; }
#header, #footer { color: #fff; background: #636; border: 1px #300 solid; padding: 6px; }
#patch { width: 100%; }
#patch h4 {font-family: verdana,arial,helvetica,sans-serif;font-size:10pt;padding:8px;background:#369;color:#fff;margin:0;}
#patch .propset h4, #patch .binary h4 {margin:0;}
#patch pre {padding:0;line-height:1.2em;margin:0;}
#patch .diff {width:100%;background:#eee;padding: 0 0 10px 0;overflow:auto;}
#patch .propset .diff, #patch .binary .diff {padding:10px 0;}
#patch span {display:block;padding:0 10px;}
#patch .modfile, #patch .addfile, #patch .delfile, #patch .propset, #patch .binary, #patch .copfile {border:1px solid #ccc;margin:10px 0;}
#patch ins {background:#dfd;text-decoration:none;display:block;padding:0 10px;}
#patch del {background:#fdd;text-decoration:none;display:block;padding:0 10px;}
#patch .lines, .info {color:#888;background:#fff;}
--></style>
<div id="msg">
<dl class="meta">
<dt>Revision</dt> <dd><a href="http://trac.webkit.org/projects/webkit/changeset/197155">197155</a></dd>
<dt>Author</dt> <dd>benjamin@webkit.org</dd>
<dt>Date</dt> <dd>2016-02-25 18:04:42 -0800 (Thu, 25 Feb 2016)</dd>
</dl>
<h3>Log Message</h3>
<pre>[JSC] Temporal Dead Zone checks on "this" are eliminated when doing OSR Entry to FTL
https://bugs.webkit.org/show_bug.cgi?id=154664
Reviewed by Saam Barati.
When doing OSR Enter into a constructor, we lose the information
that this may have been set to empty by a previously executed block.
All the code just assumed the type for a FlushedJS value and thus
not an empty value. It was then okay to eliminate the TDZ checks.
In this patch, the values on root entry now assume they may be empty.
As a result, the SetArgument() for "this" has "empty" as possible
type and the TDZ checks are no longer eliminated.
* dfg/DFGInPlaceAbstractState.cpp:
(JSC::DFG::InPlaceAbstractState::initialize):</pre>
<h3>Modified Paths</h3>
<ul>
<li><a href="#trunkSourceJavaScriptCoreChangeLog">trunk/Source/JavaScriptCore/ChangeLog</a></li>
<li><a href="#trunkSourceJavaScriptCoredfgDFGInPlaceAbstractStatecpp">trunk/Source/JavaScriptCore/dfg/DFGInPlaceAbstractState.cpp</a></li>
</ul>
</div>
<div id="patch">
<h3>Diff</h3>
<a id="trunkSourceJavaScriptCoreChangeLog"></a>
<div class="modfile"><h4>Modified: trunk/Source/JavaScriptCore/ChangeLog (197154 => 197155)</h4>
<pre class="diff"><span>
<span class="info">--- trunk/Source/JavaScriptCore/ChangeLog 2016-02-26 02:04:01 UTC (rev 197154)
+++ trunk/Source/JavaScriptCore/ChangeLog 2016-02-26 02:04:42 UTC (rev 197155)
</span><span class="lines">@@ -1,3 +1,23 @@
</span><ins>+2016-02-25 Benjamin Poulain <benjamin@webkit.org>
+
+ [JSC] Temporal Dead Zone checks on "this" are eliminated when doing OSR Entry to FTL
+ https://bugs.webkit.org/show_bug.cgi?id=154664
+
+ Reviewed by Saam Barati.
+
+ When doing OSR Enter into a constructor, we lose the information
+ that this may have been set to empty by a previously executed block.
+
+ All the code just assumed the type for a FlushedJS value and thus
+ not an empty value. It was then okay to eliminate the TDZ checks.
+
+ In this patch, the values on root entry now assume they may be empty.
+ As a result, the SetArgument() for "this" has "empty" as possible
+ type and the TDZ checks are no longer eliminated.
+
+ * dfg/DFGInPlaceAbstractState.cpp:
+ (JSC::DFG::InPlaceAbstractState::initialize):
+
</ins><span class="cx"> 2016-02-25 Ada Chan <adachan@apple.com>
</span><span class="cx">
</span><span class="cx"> Update the definition of ENABLE_VIDEO_PRESENTATION_MODE for Mac platform
</span></span></pre></div>
<a id="trunkSourceJavaScriptCoredfgDFGInPlaceAbstractStatecpp"></a>
<div class="modfile"><h4>Modified: trunk/Source/JavaScriptCore/dfg/DFGInPlaceAbstractState.cpp (197154 => 197155)</h4>
<pre class="diff"><span>
<span class="info">--- trunk/Source/JavaScriptCore/dfg/DFGInPlaceAbstractState.cpp 2016-02-26 02:04:01 UTC (rev 197154)
+++ trunk/Source/JavaScriptCore/dfg/DFGInPlaceAbstractState.cpp 2016-02-26 02:04:42 UTC (rev 197155)
</span><span class="lines">@@ -121,7 +121,7 @@
</span><span class="cx"> root->valuesAtHead.argument(i).setType(m_graph, SpecCell);
</span><span class="cx"> break;
</span><span class="cx"> case FlushedJSValue:
</span><del>- root->valuesAtHead.argument(i).makeHeapTop();
</del><ins>+ root->valuesAtHead.argument(i).makeBytecodeTop();
</ins><span class="cx"> break;
</span><span class="cx"> default:
</span><span class="cx"> DFG_CRASH(m_graph, nullptr, "Bad flush format for argument");
</span></span></pre>
</div>
</div>
</body>
</html>