How to write make rules for shared library and loadable library

A libpq library on Mac OS X is made as a loadable library (bundle). Since a
shared library version (dylib) of libpq does not exist, all programs which
use libpq are always linked with a static version of libpq.

Psql made by a current make rule:

$ ls -l /opt/pgsql/7.3/bin/psql psql
-rwxr-xr-x 1 sugita admin 188616 Dec 22 01:25 /opt/pgsql/7.3/bin/psql
$ otool -L /opt/pgsql/7.3/bin/psql
/opt/pgsql/7.3/bin/psql:
/usr/lib/libz.1.1.3.dylib (compatibility version 1.0.0, current version 1.1.3)
/usr/local/lib/libreadline.4.1.dylib (compatibility version 4.0.0, current version 4.1.0)
/usr/lib/libSystem.B.dylib (compatibility version 1.0.0, current version 63.0.0)
$

Psql made by a hand made shared library:

$ ls -l psql
-rwxr-xr-x 1 sugita wheel 138732 Dec 22 01:34 psql*
$ otool -L psql
psql:
libpq.2.2.dylib (compatibility version 2.0.0, current version 2.2.0)
/usr/lib/libz.1.1.3.dylib (compatibility version 1.0.0, current version 1.1.3)
/usr/local/lib/libreadline.4.1.dylib (compatibility version 4.0.0, current version 4.1.0)
/usr/lib/libSystem.B.dylib (compatibility version 1.0.0, current version 63.0.0)
$

Make rules for shared library and loadable library are required to
make both type of libraries. How to change PostgreSQL make rules?

Kenji Sugita