Changeset 29818 in webkit for trunk/JavaScriptCore/kjs/JSVariableObject.h

Timestamp:

Jan 27, 2008, 1:38:01 AM (17 years ago)

Author:

Darin Adler

Message:

JavaScriptCore:

Reviewed by Oliver.

• fix <rdar://problem/5657450> REGRESSION: const is broken

Test: fast/js/const.html

SunSpider said this was 0.3% slower. And I saw some Shark samples in
JSGlobalObject::put -- not a lot but a few. We may be able to regain the
speed, but for now we will take that small hit for correctness sake.

• kjs/JSGlobalObject.cpp: (KJS::JSGlobalObject::put): Pass the checkReadOnly flag in to symbolTablePut instead of passing attributes.

• kjs/JSVariableObject.h: (KJS::JSVariableObject::symbolTablePut): Removed the code to set attributes here, since we only set attributes when creating a property. Added the code to check read-only here, since we need that to implement const!

• kjs/function.cpp: (KJS::ActivationImp::put): Pass the checkReadOnly flag in to symbolTablePut instead of passing attributes.

• kjs/nodes.cpp: (KJS::isConstant): Added. (KJS::PostIncResolveNode::optimizeVariableAccess): Create a PostIncConstNode if optimizing for a local variable and the variable is constant. (KJS::PostDecResolveNode::optimizeVariableAccess): Ditto. But PostDecConstNode. (KJS::PreIncResolveNode::optimizeVariableAccess): Ditto. But PreIncConstNode. (KJS::PreDecResolveNode::optimizeVariableAccess): Ditto. But PreDecConstNode. (KJS::PreIncConstNode::evaluate): Return the value + 1. (KJS::PreDecConstNode::evaluate): Return the value - 1. (KJS::PostIncConstNode::evaluate): Return the value converted to a number. (KJS::PostDecConstNode::evaluate): Ditto. (KJS::ReadModifyResolveNode::optimizeVariableAccess): Create a ReadModifyConstNode if optimizing for a local variable and the variable is constant. (KJS::AssignResolveNode::optimizeVariableAccess): Ditto. But AssignConstNode. (KJS::ScopeNode::optimizeVariableAccess): Pass the local storage to the node optimizeVariableAccess functions, since that's where we need to look to figure out if a variable is constant. (KJS::FunctionBodyNode::processDeclarations): Moved the call to optimizeVariableAccess until after localStorage is set up. (KJS::ProgramNode::processDeclarations): Ditto.

• kjs/nodes.h: Fixed the IsConstant and HasInitializer values. They are used as flag masks, so a value of 0 will not work for IsConstant. Changed the first parameter to optimizeVariableAccess to be a const reference to a symbol table and added a const reference to local storage. Added classes for const versions of local variable access: PostIncConstNode, PostDecConstNode, PreIncConstNode, PreDecConstNode, ReadModifyConstNode, and AssignConstNode.

• kjs/object.cpp: (KJS::JSObject::put): Tweaked comments a bit, and changed the checkReadOnly expression to match the form used at the two other call sites.

LayoutTests:

Reviewed by Oliver.

• tests for <rdar://problem/5657450> REGRESSION: const is broken

• fast/js/const-expected.txt: Updated with results that express success rather than failure, and to include the many new tests I added.
• fast/js/kde/const-expected.txt: Ditto.
• fast/js/resources/const.js: Added many new tests, covering the various cases of const in globals, function locals, the slow case inside eval, the different node types, and the values of the expressions.

File:

• trunk/JavaScriptCore/kjs/JSVariableObject.h (modified) (2 diffs)

trunk/JavaScriptCore/kjs/JSVariableObject.h

@@ -83 +83 @@
 
         bool symbolTableGet(const Identifier&, PropertySlot&);
-        bool symbolTablePut(const Identifier&, JSValue*, int attr);
+        bool symbolTablePut(const Identifier&, JSValue*, bool checkReadOnly);
 
         JSVariableObjectData* d;
@@ -111 +111 @@
     }
 
-    inline bool JSVariableObject::symbolTablePut(const Identifier& propertyName, JSValue* value, int attr)
+    inline bool JSVariableObject::symbolTablePut(const Identifier& propertyName, JSValue* value, bool checkReadOnly)
     {
         size_t index = symbolTable().get(propertyName.ustring().rep());
-        if (index != missingSymbolMarker()) {
-            LocalStorageEntry& entry = d->localStorage[index];
-            entry.value = value;
-            entry.attributes = attr;
+        if (index == missingSymbolMarker())
+            return false;
+        LocalStorageEntry& entry = d->localStorage[index];
+        if (checkReadOnly && (entry.attributes & ReadOnly))
             return true;
-        }
-
-        return false;
+        entry.value = value;
+        return true;
     }