Changeset 242747 in webkit

Timestamp:

Mar 11, 2019, 3:37:43 PM (7 years ago)

Author:

ysuzuki@apple.com

Message:

[JSC] Make StaticStringImpl & StaticSymbolImpl actually static
​https://bugs.webkit.org/show_bug.cgi?id=194212

Reviewed by Mark Lam.

Avoid mutation onto refcounts if isStatic() returns true so that the content of StaticStringImpl never gets modified.

• wtf/text/StringImpl.h:

(WTF::StringImpl::ref):
(WTF::StringImpl::deref):

Location:

trunk/Source/WTF

Files:

• ChangeLog (modified) (1 diff)
• wtf/text/StringImpl.h (modified) (2 diffs)

trunk/Source/WTF/ChangeLog

@@ +1 @@
+2019-03-11  Yusuke Suzuki  <ysuzuki@apple.com>
+
+        [JSC] Make StaticStringImpl & StaticSymbolImpl actually static
+        https://bugs.webkit.org/show_bug.cgi?id=194212
+
+        Reviewed by Mark Lam.
+
+        Avoid mutation onto refcounts if `isStatic()` returns true so that the content of StaticStringImpl never gets modified.
+
+        * wtf/text/StringImpl.h:
+        (WTF::StringImpl::ref):
+        (WTF::StringImpl::deref):
+
 2019-03-11  Sihui Liu  <sihui_liu@apple.com>
 

trunk/Source/WTF/wtf/text/StringImpl.h

@@ -1065 +1065 @@
     STRING_STATS_REF_STRING(*this);
 
+    if (UNLIKELY(isStatic()))
+        return;
     m_refCount += s_refCountIncrement;
 }
@@ -1072 +1074 @@
     STRING_STATS_DEREF_STRING(*this);
 
+    if (UNLIKELY(isStatic()))
+        return;
     unsigned tempRefCount = m_refCount - s_refCountIncrement;
     if (!tempRefCount) {