<!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>[207377] trunk</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/207377">207377</a></dd>
<dt>Author</dt> <dd>sbarati@apple.com</dd>
<dt>Date</dt> <dd>2016-10-15 13:56:24 -0700 (Sat, 15 Oct 2016)</dd>
</dl>
<h3>Log Message</h3>
<pre>Assertion failed under operationToLowerCase with a rope with zero length
https://bugs.webkit.org/show_bug.cgi?id=163314
Reviewed by Mark Lam.
JSTests:
* stress/to-lower-case-intrinsic-on-empty-rope.js: Added.
(assert):
(returnRope.helper):
(returnRope):
(lower):
Source/JavaScriptCore:
There are some ways to get JSC to create empty rope strings. ToLowerCase
inside the DFG/FTL goes to the slow path when the argument is a rope.
operationToLowerCase was calling into a WTF string function that
assumed we are passing it a this value that has non-zero length.
However, we were calling it with a string that did have zero length.
To fix this, we make operationToLowerCase return the empty JSString
if it is going to make a string with zero length.
* dfg/DFGOperations.cpp:
* jsc.cpp:
(GlobalObject::finishCreation):
(functionIsRope):</pre>
<h3>Modified Paths</h3>
<ul>
<li><a href="#trunkJSTestsChangeLog">trunk/JSTests/ChangeLog</a></li>
<li><a href="#trunkSourceJavaScriptCoreChangeLog">trunk/Source/JavaScriptCore/ChangeLog</a></li>
<li><a href="#trunkSourceJavaScriptCoredfgDFGOperationscpp">trunk/Source/JavaScriptCore/dfg/DFGOperations.cpp</a></li>
<li><a href="#trunkSourceJavaScriptCorejsccpp">trunk/Source/JavaScriptCore/jsc.cpp</a></li>
</ul>
<h3>Added Paths</h3>
<ul>
<li><a href="#trunkJSTestsstresstolowercaseintrinsiconemptyropejs">trunk/JSTests/stress/to-lower-case-intrinsic-on-empty-rope.js</a></li>
</ul>
</div>
<div id="patch">
<h3>Diff</h3>
<a id="trunkJSTestsChangeLog"></a>
<div class="modfile"><h4>Modified: trunk/JSTests/ChangeLog (207376 => 207377)</h4>
<pre class="diff"><span>
<span class="info">--- trunk/JSTests/ChangeLog 2016-10-15 15:04:01 UTC (rev 207376)
+++ trunk/JSTests/ChangeLog 2016-10-15 20:56:24 UTC (rev 207377)
</span><span class="lines">@@ -1,3 +1,16 @@
</span><ins>+2016-10-15 Saam Barati <sbarati@apple.com>
+
+ Assertion failed under operationToLowerCase with a rope with zero length
+ https://bugs.webkit.org/show_bug.cgi?id=163314
+
+ Reviewed by Mark Lam.
+
+ * stress/to-lower-case-intrinsic-on-empty-rope.js: Added.
+ (assert):
+ (returnRope.helper):
+ (returnRope):
+ (lower):
+
</ins><span class="cx"> 2016-10-14 Benjamin Poulain <bpoulain@apple.com>
</span><span class="cx">
</span><span class="cx"> [JSC] op_negate should with any type
</span></span></pre></div>
<a id="trunkJSTestsstresstolowercaseintrinsiconemptyropejs"></a>
<div class="addfile"><h4>Added: trunk/JSTests/stress/to-lower-case-intrinsic-on-empty-rope.js (0 => 207377)</h4>
<pre class="diff"><span>
<span class="info">--- trunk/JSTests/stress/to-lower-case-intrinsic-on-empty-rope.js (rev 0)
+++ trunk/JSTests/stress/to-lower-case-intrinsic-on-empty-rope.js 2016-10-15 20:56:24 UTC (rev 207377)
</span><span class="lines">@@ -0,0 +1,26 @@
</span><ins>+function assert(b) {
+ if (!b)
+ throw new Error("bad!");
+}
+
+function returnRope() {
+ function helper(r, s) {
+ // I'm paranoid about RegExp matching constant folding.
+ return s.match(r)[1];
+ }
+ noInline(helper);
+ return helper(/(b*)fo/, "fo");
+}
+noInline(returnRope);
+
+function lower(a) {
+ return a.toLowerCase();
+}
+noInline(lower);
+
+for (let i = 0; i < 10000; i++) {
+ let rope = returnRope();
+ assert(!rope.length);
+ assert(isRope(rope)); // Keep this test future proofed. If this stops returning a rope, we should try to find another way to return an empty rope.
+ lower(rope);
+}
</ins></span></pre></div>
<a id="trunkSourceJavaScriptCoreChangeLog"></a>
<div class="modfile"><h4>Modified: trunk/Source/JavaScriptCore/ChangeLog (207376 => 207377)</h4>
<pre class="diff"><span>
<span class="info">--- trunk/Source/JavaScriptCore/ChangeLog 2016-10-15 15:04:01 UTC (rev 207376)
+++ trunk/Source/JavaScriptCore/ChangeLog 2016-10-15 20:56:24 UTC (rev 207377)
</span><span class="lines">@@ -1,3 +1,23 @@
</span><ins>+2016-10-15 Saam Barati <sbarati@apple.com>
+
+ Assertion failed under operationToLowerCase with a rope with zero length
+ https://bugs.webkit.org/show_bug.cgi?id=163314
+
+ Reviewed by Mark Lam.
+
+ There are some ways to get JSC to create empty rope strings. ToLowerCase
+ inside the DFG/FTL goes to the slow path when the argument is a rope.
+ operationToLowerCase was calling into a WTF string function that
+ assumed we are passing it a this value that has non-zero length.
+ However, we were calling it with a string that did have zero length.
+ To fix this, we make operationToLowerCase return the empty JSString
+ if it is going to make a string with zero length.
+
+ * dfg/DFGOperations.cpp:
+ * jsc.cpp:
+ (GlobalObject::finishCreation):
+ (functionIsRope):
+
</ins><span class="cx"> 2016-10-14 Benjamin Poulain <bpoulain@apple.com>
</span><span class="cx">
</span><span class="cx"> [JSC] op_negate should with any type
</span></span></pre></div>
<a id="trunkSourceJavaScriptCoredfgDFGOperationscpp"></a>
<div class="modfile"><h4>Modified: trunk/Source/JavaScriptCore/dfg/DFGOperations.cpp (207376 => 207377)</h4>
<pre class="diff"><span>
<span class="info">--- trunk/Source/JavaScriptCore/dfg/DFGOperations.cpp 2016-10-15 15:04:01 UTC (rev 207376)
+++ trunk/Source/JavaScriptCore/dfg/DFGOperations.cpp 2016-10-15 20:56:24 UTC (rev 207377)
</span><span class="lines">@@ -1523,6 +1523,9 @@
</span><span class="cx">
</span><span class="cx"> const String& inputString = string->value(exec);
</span><span class="cx"> RETURN_IF_EXCEPTION(scope, nullptr);
</span><ins>+ if (!inputString.length())
+ return vm.smallStrings.emptyString();
+
</ins><span class="cx"> String lowercasedString = inputString.is8Bit() ? inputString.convertToLowercaseWithoutLocaleStartingAtFailingIndex8Bit(failingIndex) : inputString.convertToLowercaseWithoutLocale();
</span><span class="cx"> if (lowercasedString.impl() == inputString.impl())
</span><span class="cx"> return string;
</span></span></pre></div>
<a id="trunkSourceJavaScriptCorejsccpp"></a>
<div class="modfile"><h4>Modified: trunk/Source/JavaScriptCore/jsc.cpp (207376 => 207377)</h4>
<pre class="diff"><span>
<span class="info">--- trunk/Source/JavaScriptCore/jsc.cpp 2016-10-15 15:04:01 UTC (rev 207376)
+++ trunk/Source/JavaScriptCore/jsc.cpp 2016-10-15 20:56:24 UTC (rev 207377)
</span><span class="lines">@@ -789,6 +789,7 @@
</span><span class="cx"> static EncodedJSValue JSC_HOST_CALL functionSetGlobalConstRedeclarationShouldNotThrow(ExecState*);
</span><span class="cx"> static EncodedJSValue JSC_HOST_CALL functionGetRandomSeed(ExecState*);
</span><span class="cx"> static EncodedJSValue JSC_HOST_CALL functionSetRandomSeed(ExecState*);
</span><ins>+static EncodedJSValue JSC_HOST_CALL functionIsRope(ExecState*);
</ins><span class="cx">
</span><span class="cx"> struct Script {
</span><span class="cx"> enum class StrictMode {
</span><span class="lines">@@ -1007,6 +1008,7 @@
</span><span class="cx">
</span><span class="cx"> addFunction(vm, "getRandomSeed", functionGetRandomSeed, 0);
</span><span class="cx"> addFunction(vm, "setRandomSeed", functionSetRandomSeed, 1);
</span><ins>+ addFunction(vm, "isRope", functionIsRope, 1);
</ins><span class="cx">
</span><span class="cx"> addFunction(vm, "is32BitPlatform", functionIs32BitPlatform, 0);
</span><span class="cx">
</span><span class="lines">@@ -1805,6 +1807,15 @@
</span><span class="cx"> return JSValue::encode(jsUndefined());
</span><span class="cx"> }
</span><span class="cx">
</span><ins>+EncodedJSValue JSC_HOST_CALL functionIsRope(ExecState* exec)
+{
+ JSValue argument = exec->argument(0);
+ if (!argument.isString())
+ return JSValue::encode(jsBoolean(false));
+ const StringImpl* impl = jsCast<JSString*>(argument)->tryGetValueImpl();
+ return JSValue::encode(jsBoolean(!impl));
+}
+
</ins><span class="cx"> EncodedJSValue JSC_HOST_CALL functionReadline(ExecState* exec)
</span><span class="cx"> {
</span><span class="cx"> Vector<char, 256> line;
</span></span></pre>
</div>
</div>
</body>
</html>