README file for TDebug, an alternative tcl/tk-debugger.

The current Maintainer of TDebug is David Dougherty <david.dougherty@amd.com> 

Copyright (C) 1993 Gregor Schmid 

This software is copyrighted by Gregor Schmid. The following terms apply to all files associated with the software unless
explicitly disclaimed in individual files. 

The authors hereby grant permission to use, copy, modify, distribute, and license this software and its documentation for any
purpose, provided that existing copyright notices are retained in all copies and that this notice is included verbatim in any
distributions. No written agreement, license, or royalty fee is required for any of the authorized uses. Modifications to this
software may be copyrighted by their authors and need not follow the licensing terms described here, provided that the new
terms are clearly indicated on the first page of each file where they apply. 

IN NO EVENT SHALL THE AUTHORS OR DISTRIBUTORS BE LIABLE TO ANY PARTY FOR DIRECT, INDIRECT,
SPECIAL, INCIDENTAL, OR CONSEQUENTIAL DAMAGES ARISING OUT OF THE USE OF THIS SOFTWARE, ITS
DOCUMENTATION, OR ANY DERIVATIVES THEREOF, EVEN IF THE AUTHORS HAVE BEEN ADVISED OF THE
POSSIBILITY OF SUCH DAMAGE. 

THE AUTHORS AND DISTRIBUTORS SPECIFICALLY DISCLAIM ANY WARRANTIES, INCLUDING, BUT NOT LIMITED TO,
THE IMPLIED WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE, AND
NON-INFRINGEMENT. THIS SOFTWARE IS PROVIDED ON AN "AS IS" BASIS, AND THE AUTHORS AND
DISTRIBUTORS HAVE NO OBLIGATION TO PROVIDE MAINTENANCE, SUPPORT, UPDATES, ENHANCEMENTS, OR
MODIFICATIONS. 

Files included in this distribution

    README older version of this file README.html this file TdChoose.tcl the TDebug front end TdDebug.tcl the debugger
    ChangeLog development history
    
    README.html is much more complete than this file (README)

General

TDebug uses a different approach than any other debugger I've seen for Tcl/Tk. If you know the emacs-lisp debugger `edebug'
the following may seem familiar. 

TDebug is solely based on Tcl/Tk, there is no C-code, which makes it very easy to install. It works by parsing and redefining
Tcl/Tk-procs, inserting calls to `td_eval' at certain points, which takes care of the display, stepping, breakpoints, variables etc. 

The advantages are that TDebug knows which statement in what proc is currently being executed and can give visual feedback
by highlighting it. All currently accessible variables and their values are displayed as well. Code can be evaluated in the context of
the current proc. Breakpoints can be set and deleted with the mouse. 

Unfortunately there are back-draws to this approach. Preparation of large procs is slow and due to Tcl's dynamic nature there is
no guarantee, that a proc can be prepared at all. 

This problem has been alleviated somewhat with the introduction of partial preparation of procs. There is still no possibility to get
at code running in global context, but I'm not sure if that would be useful anyway. 

News

New since version 1.6 (From David Dougherty) 

    If tix is available a tixPanedWindow is drawn between the listing and the variable window providing much better control over
    the display. 
    Add control to the Debugger Variable menu to control whether variable values are wrapped in the widget or not also
    controlled by the wrapvars variable. 
    Added searching to the variable display, regular expression is applied to the variables and values on subsequent display. 

New since version 1.5 (From David Dougherty) 

    Added new color control for more consistent display across application. 
    Added find field for procedure name searches, activated by <Return>. 
    Fixed a bug in breakpoint routine caused by embedded []{} characters.  It's still not perfect but much better. 
    README is now solely maintained in HTML (this file). 

New since version 1.0 

    Compatibility with Tcl8.0/Tk8.0 

New since version 0.9 

    compatibility with Tk 4.0 
    chooser layout changed 
    Name program to debug on the command line 

New since version 0.3 

    display any proc without preparing it first 
    partial preparing and restoring 
    detach from applications on exit 
    faster parsing (thanks to Alessandro Rubini) 
    parsing bugs fixed, should now parse any proc 
    cline extensions included for `Eval:' line 
    can eval at global level 
    optionally hide global variables and arrays 
    optionally hide tk_* procs and others 
    chooser now recognizes if procs are redefined 
    a LOT more configuration options: 
    Geometry for all toplevels 
    Style of tags in listing 
    
Credits

Thanks to: 

    John Ousterhout <ouster@sprite.berkeley.edu> for Tcl/Tk. 
    Alessandro Rubini <rubini@ipvvis.unipv.it> for numerous good ideas and speedups for parsing . 
    Renzo Lazzarato rlazzara@France.Sun.COM> fixed the  td_priv(debugdir) problem. 
    David Dougherty <david.dougherty@amd.com> for taking over TDebug in January 1998. 
    Norbert Erkelund <etmnoer@etm.ericsson.se> for help with the Tk8.0 breakpoint problem. 
