gcc3 ABI compatibility?

[Andrew Haley]

Michael VanLoon wrote:
> Anyone?

It's all documented at gcc.gnu.org/releases.html

> On 6/3/08 4:37 PM, "Michael VanLoon" <michaelv@yahoo-inc.com> wrote:

>> Have there been compatibility-breaking changes to the ABI among the
>> different versions of gcc3?

It depends on the particular target; sometimes we have to break ABI
compatibility to fix bugs.  In general, yes.

Also, C++ support was massively reworked around gcc 3.4.

>> In other words, say I build a C++ library with some exported class
>> interfaces and such. I use a version of gcc3 (maybe 3.4.6), then upgrade it
>> to a later version of gcc3 (maybe 3.5.1).

3.5.1 ?

>> Will the libraries break if I
>> compile new client code against the library built with the older compiler?

Probably.  The multi-vendor C++ ABI made this a lot better, but there are
still incompatibilities.  We don't break ABI compatibility on release branches,
so you can safely assume that 3.4.2 is compatible with 3.4.1.

Andrew.