Changeset 35368 in webkit for trunk/JavaScriptCore/VM/CodeGenerator.cpp

Timestamp:

Jul 25, 2008, 8:52:24 PM (17 years ago)

Author:

[email protected]

Message:

Bug 19718: Named anonymous functions are slow accessing global variables
<​https://bugs.webkit.org/show_bug.cgi?id=19718>

Reviewed by Cameron Zwarich.

To fix this we switch over to an activation-like scope object for
on which we attach the function name property, and add logic to
prevent cross scope assignment to read only properties.

File:

• trunk/JavaScriptCore/VM/CodeGenerator.cpp (modified) (3 diffs)

trunk/JavaScriptCore/VM/CodeGenerator.cpp

@@ -623 +623 @@
 }
 
-bool CodeGenerator::findScopedProperty(const Identifier& property, int& index, size_t& stackDepth)
+bool CodeGenerator::findScopedProperty(const Identifier& property, int& index, size_t& stackDepth, bool forWriting)
 {
     // Cases where we cannot optimise the lookup
@@ -645 +645 @@
         // Found the property
         if (!entry.isNull()) {
+            if (entry.isReadOnly() && forWriting) {
+                stackDepth = 0;
+                index = missingSymbolMarker();
+                return false;
+            }
             stackDepth = depth;
             index = entry.getIndex();
@@ -663 +668 @@
     size_t depth = 0;
     int index = 0;
-    if (!findScopedProperty(property, index, depth)) {
+    if (!findScopedProperty(property, index, depth, false)) {
         // We can't optimise at all :-(
         emitOpcode(op_resolve);