54669: add --disable-link-all-libs configure option

When this is used, libraries only needed by specific modules will only
be linked to those modules (currently libgdbm and libpcre2). When
--enable-cap is used, the main shell also uses libcap functions so we
want to link that either way.

Speaking of the cap module, it did some weird thing where it always
compiles but creates useless builtins that only error, which means you
can't rely on zmodload to check if they'll work. I'm sure someone will
complain about me changing this but I'm going to at least try it and see
if someone has a good reason for it.

The gdbm module also has a big ifdef for the whole module, but instead
of dummy builtins it just does #error, so remove that. We won't try to
compile it if the user didn't ask for it, and if the user asked for it
and it wouldn't compile, configure won't create a Makefile. Using the
ac_cv_ cache variables in db_gdbm.mdd also doesn't actually work
properly, those will remain set and enable the module to be linked after
you pass --disable-gdbm and you will get the aforementioned #error. Use
the enable_gdbm variable instead, like pcre.mdd does (and also cap.mdd
now that I evilly made it conditional on --enable-cap).

1 files changed, 7 insertions, 0 deletions

diff --git a/ChangeLog b/ChangeLog
index 12e5e4512..e87b638a1 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,10 @@
+2026-06-07  Mikael Magnusson  <mikachu@gmail.com>
+
+	* 54669: Src/Modules/cap.c, Src/Modules/cap.mdd,
+	Src/Modules/db_gdbm.c, Src/Modules/db_gdbm.mdd,
+	Src/Modules/pcre.mdd, Src/mkmakemod.sh, configure.ac: add
+	--disable-link-all-libs configure option
+
 2026-06-06  dana  <dana@dana.is>
 
 	* unposted: NEWS: better document hlgroups, termquery, etc