TIP #34 Version 1.1: TEA 2.0

This is not necessarily the current version of this TIP.


TIP:34
Title:TEA 2.0
Version:$Revision: 1.1 $
Author:Mo DeJong <mdejong at cygnus dot com>
State:Draft
Type:Project
Tcl-Version:8.4
Vote:Pending
Created:Thursday, 03 May 2001

Abstract

The original TEA specification, documentation, and implementation have fallen out of date. Numerous complaints about the difficulty of creating a TEA compliant package have appeared on news:comp.lang.tcl The existing build system works but it is a pain to maintain mostly because there are two build systems, one for unix and another for windows. This document describes how some of these concerns can be addressed.

Rationale

As new software is released, existing documentation becomes obsolete. Some of the existing TEA documentation is now so badly out of date that suggested software releases are no longer available. The solution to this problem is simple, the TEA documentation and implementation must be updated.

The build system itself is in need of an update. The Unix and Windows versions of the build system are not synchronized. There are a number of features that are simply not implemented in the Windows version. The most straightforward way of dealing with this problem is to merge the two build systems. Some popular extensions have already taken this approach, Itcl for example uses a single configure.in script to build the Unix and Windows versions. While switching to a single configure.in is a big step, it will significantly simplify maintenance and make life a lot easier in the long run.

Tcl's build system does not depend on config.guess and config.sub to determine build and host triples. Instead, it depends on the output of uname -s and uname -r. That works for native builds but makes it very painful to cross compile. For example, a user might want to build Windows binaries under Linux. Tcl's existing build system makes this much harder than it needs to be. Upgrading to autoconf 2.50 is the best way to address this problem.

Tcl's build system passes a large number of -D flags to the compiler instead of making use of a config.h file. Personal experience has shown that using a config.h file is a superior way of dealing with configure time defines.

Implementation Notes

Implementing this TIP is by no means an easy task. Build system changes are by far the most dangerous since a mistake that breaks something on some infrequently used configuration will not be not