[gentoo-dev] [rfc] dev-libs/expat[unicode] and dev-libs/libbsd dependency

[Sebastian Pipping]

Hi!


The next release of dev-libs/expat is not far away and there are two
things that I would appreciate input with, before the next bump in Gentoo:


-DXML_UNICODE_WCHAR_T issues and Gentoo/Debian mismatch
=======================================================

With USE=unicode, on Gentoo two extra libraries are built:

 * libexpatu.so (with CPPFLAGS=-DXML_UNICODE)
 * libexpatw.so (with CPPFLAGS=-DXML_UNICODE_WCHAR_T)
           ^
However, -DXML_UNICODE_WCHAR_T has only ever worked with 2-byte wchar_t,
while 4-byte wchar_t seems mainstream on Linux (and GCC -fshort-wchar
would required libc to have the same, if you actually wanted to pass
those wchar_t strings to wprintf and friends).

So libexpatw.so in Gentoo is not functional at the moment.

To make things worse, Debian has libexpatw.so with
CPPFLAGS=-DXML_UNICODE, which corresponds to current libexpatu.so in
Gentoo, rather than libexpatw.so.


How do you evaluate these options:

 a) Keep libexpatu.so + change libexpatw.so to CPPFLAGS=-DXML_UNICODE

 b) Drop libexpatu.so + change libexpatw.so to CPPFLAGS=-DXML_UNICODE


Depend on dev-libs/libbsd
=========================

The next release is very likely to add (optional but helpful) support
for arc4random_buf that dev-libs/libbsd provides (especially on systems
with glibc prior to 2.25) [1].  I wonder if Expat's proximity to @system
has any strong implications on whether

 A) libbsd should be a default-off use dependency
      IUSE="libbsd"  RDEPEND="libbsd? ( dev-libs/libbsd )"

 B) libbsd could be a default-on use dependency
      IUSE="+libbsd"  RDEPEND="libbsd? ( dev-libs/libbsd )"

 C) libbsd could even go into DEPEND and RDEPEND directly, or
      RDEPEND="dev-libs/libbsd"

 D) libbsd should not become any kind of future dependency of
    dev-libs/expat.


Thanks for your time!

Best



Sebastian


[1] https://github.com/libexpat/libexpat/pull/30