Bug 148440

Summary: DFG::AbstractHeap should be able to distinguish between heap locations that are user-observable and heap locations that are VM-internal
Product: WebKit Reporter: Filip Pizlo <fpizlo>
Component: JavaScriptCoreAssignee: Nobody <webkit-unassigned>
Status: NEW ---    
Severity: Normal    
Priority: P2    
Version: Other   
Hardware: All   
OS: All   

Description Filip Pizlo 2015-08-25 12:02:28 PDT
If you write to a VM-internal heap, it shouldn't clobber exit, because the user won't know that you had done it.

Note that it's not as simple as that.  Depending on how you define "VM-internal", a VM-internal write might still put the system in a state where OSR exit is invalid even though the write was not user-observable.  So, it's not entirely obvious that this is a good idea, but it's worth thinking about.