infinite recursions

[Biscondi, Philippe]

Hi,

I am using m4 for the raw sake of symbol substitution.

The issue is that endless substitution is not de detected, like in the
following:

<<<<<<<<<<<<<<<
define(`x', `a y')
define(`y', `c b x')
x
y
>>>>>>>>>>>>>>>

However using m4 for the purpose above is perfectly natural (and the
simplest way to
do it -- i don't know of other basic unix tools that can accomplish it,
except cpp);
as the file to be processed is generated automatically from custom
configuration
files, it would be nice to warn the user that (s)he did a mistake in the
configuration
files, resulting in a loop.

I don't know of any m4 variant that detects symbolic loops in preprocessing.
Sounds like a bug anyway: file processing should be stopped.

---------------------------------------
Philippe Biscondi