How much libc++ ABI changes FreeBSD can consume?

[Zhihao Yuan]

Hi,

I'm sending this email because

 a. FreeBSD has been stuck on libc++ V1 ABI
    long enough.  I would like to learn some details.
 b. There is an ongoing discussion in the C++
    standards committee talking about whether
    the standard library should break ABI on a
    regular basis.

Here are my questions:

 1. Is FreeBSD waiting for libc++ V2 ABI to freeze?
    If so, will FreeBSD switch to V2 ABI afterwards?
 2. The pkgs are tagged with __FreeBSD_version,
    is that enough to allow libc++ ABI to change
    at every FreeBSD (major) release?
 3. Is MFC required for libc++ updates?  If so, how
    does that affect ABI changes?
 4. Is there any desire to make C++ ABI breakage
    smoother by ultilzing mechanisms such as
    Symbol.map?

Thanks,

-- 
Zhihao Yuan, ID lichray
The best way to predict the future is to invent it.
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