Re: Bug in AC_CACHE_VAL (maybe)

[Akim Demaille]

| Current CVS autoconf run for help2man 1.24, out-of the box yields:
| configure.in:5: m4.exe: Warning: Too few arguments to built-in `m4_regexp'
| configure.in:5: m4.exe: Warning: Too few arguments to built-in `m4_if'
| 
| The likely culprit seems to be AC_CACHE_VAL.
| Below are the contents of aclocal.m4 (after autoupdating and removing the
| spurious '([])' from AS_MESSAGE_LOG_FD).
| My guess is that the ifelse is being executed by the check for AC_DEFINE
| in the second part of AC_CACHE_VAL. Question is: is this a bonafide
| autoconf bug, or simply a broken user-defined macro (and if the latter,
| what is the proper way to write this macro)?
| 
| == aclocal.m4 starts here
| changequote()
| define(RIGHT_BRACKET, ])
| changequote([, ])

This is useless and dangerous.  The fact that RIGHT_BRACKET is indeed
defined as a right bracket does not imply that *when used* it is still
``protected''.  So even without looking at the rest of the code I can
tell you this code is doomed.

First, get rid of it, then it will work better.  But anyway, could you
send the original macro?  What you sent seems autoupdated too
violently: it looks like AC_PATH_PROG or so is expanded.

Here is how I would 2.13 write what you sent:

configure.ac
Description: Binary data

which gives:

/tmp % ace                                                       nostromo 12:16
/tmp % ./configure                                               nostromo 12:16
checking for perl... perl
checking for perl... no

And here is how I would 2.49 write it:

configure.ac
Description: Binary data

And finally, while I'm no Perl specialist, ISTR there are
letter-variables for this, using $] is asking for troubles :)