Bug 67690
| Summary: | Remove virtual functions from JSCell | ||
|---|---|---|---|
| Product: | WebKit | Reporter: | Mark Hahnenberg <mhahnenberg> |
| Component: | JavaScriptCore | Assignee: | Mark Hahnenberg <mhahnenberg> |
| Status: | RESOLVED FIXED | ||
| Severity: | Normal | ||
| Priority: | P2 | ||
| Version: | 528+ (Nightly build) | ||
| Hardware: | Unspecified | ||
| OS: | Unspecified | ||
| Bug Depends on: | 67691, 67727, 67875, 67902, 67909, 67911, 68404, 68651, 68741, 68839, 68851, 68937, 69024, 69156, 69186, 69311, 69593, 69659, 69673, 69677, 69679, 69807, 69810, 69851, 69858, 69872, 69884, 70162, 70163, 70257, 70271, 70281, 70439, 70638, 70738, 70740, 70741, 70958 | ||
| Bug Blocks: | 69382 | ||
Mark Hahnenberg
In order to maintain more control over exactly how JS objects are laid out, we need to remove the C++ virtual functions from JS object implementations due to the freedom that C++ compilers are given with how they lay out objects with vtable pointers. We can also save a little bit of memory due to the lack of vtable pointer in each object. The methods in JSCell that either need to be made non-virtual or removed are the following:
isGetterSetter
isAPIValueWrapper
isPropertyNameIterator
getCallData
getConstructData
getUInt32
toPrimitive
getPrimitive
toBoolean
toNumber
toString
toObject
visitChildren
put(ExecState*, const Identifier&, JSValue, PutPropertySlot&)
put(ExecState*, unsigned, JSValue)
deleteProperty(ExecState*, const Identifier&)
deleteProperty(ExecState*, unsigned)
toThisObject
getJSNumber
getOwnPropertySlot(ExecState*, const Identifier&, PropertySlot&)
getOwnPropertySlot(ExecState*, unsigned, PropertySlot&)
Destructors will be taken care of by Oliver :-) There will be a patch for each function, roughly. This will serve as the tracking bug for this task.
| Attachments | ||
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| Add attachment proposed patch, testcase, etc. |
Mark Hahnenberg
Sam helped me out a little bit and de-virtualized isGetterSetter, isAPIValueWrapper, and killed isPropertyNameIterator :-)
Mark Hahnenberg
Except the virtual destructor, which will remain for a while longer until we get around to replacing virtual destructors with finalizers, there are no longer any virtual functions in JSCell. Closing this bug.