[SR-3724] Evaluate a fully declaration-order-agnostic layout algorithm for structs

[ematejska]

Previous ID	SR-3724
Radar	rdar://problem/31411204
Original Reporter	@ematejska
Type	Sub-task
Status	Resolved
Resolution	Duplicate

Additional Detail from JIRA

Votes	0
Component/s
Labels	Sub-task, AffectsABI
Assignee	None
Priority	Medium

md5: 16998bd76284442eaff4d9e118e167dd

Parent-Task:

• SR-7809 Define layout algorithm for structs

duplicates:

• SR-3723 Determine if the layout algorithm for structs should layout fields in a different order than declared

Issue Description:

Evaluate a fully declaration-order-agnostic layout algorithm for structs to allow data members to be reordered in source without breaking binary compatibility. This is ahead of ABI Stability.

[bob-wilson]

@swift-ci create

[bob-wilson]

We also have SR-3723 "Determine if the layout algorithm for structs should layout fields in a different order than declared". These are basically the same thing – either we match the declaration order or we don't – so let's just track this in SR-3723.