Re: On the cost of libraries

[Colm Smyth <Colm Smyth sun com>]

>Subject: Re: On the cost of libraries
>From: murrayc t-online de (Murray Cumming)
>To: Colm Smyth <Colm Smyth sun com>
>Cc: dave willfork com, Sander Vesik sun com, dave arsdigita com, 
otaylor redhat com, alexl redhat com, mjs noisehavoc org, Gnome Hackers 
<gnome-hackers gnome org>
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>On Fri, 2001-11-16 at 11:24, Colm Smyth wrote:
>> Binary compatibility is an important goal, but with C++ it's effectively
>> impossible; the name-mangling format changes not infrequently, vtable 
dispatch
>> is also subject to change.  The upshot is that the ABI of a C++ library can
>> change between minor version updates so the usage scenario I described is
>> applicable only when you are targetting a well-known C++ ABI.
>
>You mean 'between minor version updates' of the compiler, right? 

Yes; thanks for calling out that clarification.

> The ABI
>of a C++ library should not change between minor version updates of that
>library.

According to best practice, the ABI of any library should not change between
minor version updates but C++ libraries have two sources of ABI incompatibility,
changes to source symbols and changes due to the compiler.

Colm.