fate of libxml2 in gcc

[Iain Sandoe]

Hi Folks,

> On 17 Jan 2026, at 12:13, Jonathan Wakely via Gcc <gcc@gcc.gnu.org> wrote:
> 
> On Fri, 16 Jan 2026 at 20:34, Jakub Jelinek via Gcc <gcc@gcc.gnu.org> wrote:
>> 
>> On Fri, Jan 16, 2026 at 03:00:40PM -0500, James K. Lowden wrote:
>>> Issues:
>>> 
>>> 1.  Bring libxml2 into the GCC repository, or not
>>> 2.  Link to libxml2 dynamically, or not
>>> 3.  Quality/stability of libxml2
>>> 4.  Maintenance burden in-tree versus build complexity ex-tree
>>> 5.  As of now libxml2 has no maintainer
>>> 
>>> Thesis: Best is to build libxml2 out of tree and not install it, linking
>>> libxml2.a into libgcobol.
>> 
>> Note, while zlib is included in gcc tree, we have --with-system-zlib
>> option that users can use to use the system libz instead of the included
>> one.

this approach ^ … 

>> And in tree vs. out of tree aren't the only options, there is also
>> the possibility to make it optionally in tree (like e.g. libisl is).
>> Users can download it (e.g. download_prerequisities does) and unpack
>> and then it is built in tree, or they don't and then it use system libisl
>> if it can find it (there are options to point it at a particular library and
>> its headers), or it is not found and not included.
> 
> Yes, I was going to suggest the download_prerequisites approach too.

… combined with this ^

would cover most bases, I’d think (efficiency if the platform has the lib
and resilience if not).

> Even if it's a hard requirement to have libxml2 (i.e. the Cobol
> front-end can't just be non-conforming and missing some features
> without it), that's analagous to libgmp, libmpfr, and libmpc which are
> hard requirements but we still don't keep a copy of the code in the
> tree.

agreed
Iain