File: libtool.info,  Node: Issues,  Next: Other implementations,  Prev: Motivation,  Up: Introduction

1.2 Implementation issues
=========================

The following issues need to be addressed in any reusable shared library
system, specifically libtool:

  1. The package installer should be able to control what sort of
     libraries are built.

  2. It can be tricky to run dynamically linked programs whose libraries
     have not yet been installed.  ‘LD_LIBRARY_PATH’ must be set
     properly (if it is supported), or programs fail to run.

  3. The system must operate consistently even on hosts that don't
     support shared libraries.

  4. The commands required to build shared libraries may differ wildly
     from host to host.  These need to be determined at configure time
     in a consistent way.

  5. It is not always obvious with what prefix or suffix a shared
     library should be installed.  This makes it difficult for
     ‘Makefile’ rules, since they generally assume that file names are
     the same from host to host.

  6. The system needs a simple library version number abstraction, so
     that shared libraries can be upgraded in place.  The programmer
     should be informed how to design the interfaces to the library to
     maximize binary compatibility.

  7. The install ‘Makefile’ target should warn the package installer to
     set the proper environment variables (‘LD_LIBRARY_PATH’ or
     equivalent), or run ‘ldconfig’.