Re: Code from installed libtexinfo.so.0 run for non-installed texi2any

[Eli Zaretskii]

> From: Gavin Smith <gavinsmith0123@gmail.com>
> Date: Sun, 5 Nov 2023 18:12:45 +0000
> Cc: pertusus@free.fr, bug-texinfo@gnu.org
> 
> So you know what a dynamically loaded library is; this contains a collection
> of functions and potentially data structures that can be loaded by running
> code and run as part of a computer program.
> 
> Usually, when such a library is installed on a system, this is for use
> generally by any program.  For example, if there is a library file
> libz.so.1, this could be linked by passing the -lz flag to the C compiler
> when building the program.  The program would be able to call functions
> in the library and so on.
> 
> The program using this library would likely be written by a different
> person, and as part of a different project, to the persons and projects
> responsible for the creation of the library.  There is an assumption that
> the library has a stable interface, and the library and programs using
> the library are worked on completely independently.
> 
> The dynamically loaded libraries used by texi2any (XS modules) are
> completely different.  Technically, they are loaded in the same way,
> by the running Perl interpreter.  But they are an integral part of the
> texi2any program.  They are intended for the use of the texi2any program
> only, not any other.

The XS modules are installed in a directory which is usually not
looked into by the dynamic linker.  Is that what you are talking
about?  If so, we have been using "non-public libraries" since long
ago, no?  Or what am I missing?

> The file was being installed under /usr/local/lib/libtexinfo.so.1, as
> if to imply that a user could link it against their programs with -ltexinfo,
> or load it with dlopen, which would be completely inappropriate.

I don't have any libtexinfo shared library here, and I don't see one
being built, let alone installed, as part of Texinfo.  is this
something new in the development sources?  If so, what code is linked
into libtexinfo?