Go forward to Future Extensions.
Go backward to Notes.
Go up to Notes.

Downward Compatibility and Debugging
====================================

   See Extensions in `gawk' not in POSIX `awk': POSIX/GNU, for a
summary of the GNU extensions to the `awk' language and program.  All
of these features can be turned off by invoking `gawk' with the `-W
compat' option, or with the `-W posix' option.

   If `gawk' is compiled for debugging with `-DDEBUG', then there is
one more option available on the command line:

`-W parsedebug'
     Print out the parse stack information as the program is being
     parsed.

   This option is intended only for serious `gawk' developers, and not
for the casual user.  It probably has not even been compiled into your
version of `gawk', since it slows down execution.