Bug 303079

Summary: Remove use of CompactPtr for Structure::m_classInfo.
Product: WebKit Reporter: Mark Lam <mark.lam>
Component: JavaScriptCoreAssignee: Mark Lam <mark.lam>
Status: RESOLVED FIXED    
Severity: Normal CC: webkit-bug-importer
Priority: P2 Keywords: InRadar
Version: WebKit Nightly Build   
Hardware: Unspecified   
OS: Unspecified   

Mark Lam
Reported 2025-11-24 21:35:41 PST
ClassInfo is located in CONST_DATA, and it is not guaranteed that CONST_DATA will be located in the same 36-bit address range that applies to heap allocated memory. Also, sizeof(Structure) on iOS (and peers) is 104. With the removal of this CompactPtr, sizeof(Structure) increases to 112. However, on iOS, Structures require 32 atom (alignment), which takes its size class up to 128. This means the size increase will be completely inconsequential.
Attachments
Radar WebKit Bug Importer
Comment 1 2025-11-24 21:36:10 PST
Mark Lam
Comment 2 2025-11-24 21:48:42 PST
EWS
Comment 3 2025-11-27 17:29:10 PST
Committed 303621@main (150dba5b9324): <https://commits.webkit.org/303621@main> Reviewed commits have been landed. Closing PR #54434 and removing active labels.
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