UNDER CONSTRUCTION

1.  Tcl Debugging

Weld is a true debugger of Tcl in the sense that it dynamically intercepts calls to procs rather than instrumenting code. This means the debugger does not need to preprocess source files and so can be used even with embedded Tcl applications, ie. Tcl with C extensions.

Another distinctive feature of the Weld debugger is that it deals only with code executed inside of procs. Code outside of procs is considered infrastructure or glue code and therefore ignored. This eliminates distracting extraneous support code such as proc, namespace and variable calls.

The name Weld is an acronym for Warning Enabled Lazy Debugger.

2.  Usage

The debugger can be used when running programs from wted using <Shift-F5> and selecting the Weld Debugging option (see Screenshot).

3.  Command-line

The simplest way to use weld for debugging from the command line is to invoke it as wtdb, eg.

  wtdb main.tcl

Similarly compiled program may be debugged on systems where gdb is available with:

  wtdb a.out

which uses tdb as a frontend to gdb.

Weld may also be used to debug programs directly from the command line by invoking it as:

 weld -Wdebug=2 foo.tcl

4.  Weld under DDD

In addition to wtdb other programs may be act as the controlling interface or GUI, such as DDD or Emacs.

DDD may be used as the GUI interface using:

 ddd --args weld -Wdebug=2 file.tcl arg1 arg2 ...

See emacs documentation on running gdb in a sub-shell.

5.  Dual-level Debugging

It is also possible to debug both at the C (low) and Tcl (high) levels simultaneously using somthing like:

  wtdb ~/bin/weld -Wdebug=2 main.tcl

© 2008 Peter MacDonald