On Fri May 24 12:35 2002 +0200, Akim Demaille wrote:
> | While working on this, I noticed that the current autom4te code
> | reverses the order of the `-I' options before passing them to m4. The
> | documentation says:
> |
> | `--include=DIR'
> | `-I DIR'
> | Also look for input files in DIR. Multiple invocations
> | accumulate. Contrary to M4 but in agreement with common sense,
> | directories are browsed from last to first.
> |
> | From my perspective, this behavior is extremely counter-intuitive.
> | Every other tool that I know of that accepts a `-I' option (including
> | gcc, GNU make, GNU m4, and perl) prepends the arguments to the search
> | path in the order specified. As a result, I was extremely surprised
> | to discover that autoconf does the reverse.
>
> Because the logic is to respect the last flag occurrence first for all
> the other flags but this one. Honestly, to me it is a serious bug in
> all the other implementations.
>
> And it *does* matter to autom4te, for instance because you do want
> sometimes to say ``I want _my_ macros to be used first''. So you
> `autom4te -l autoconf -I .'. But then, you want `.' to take precedence.
I completely agree that the directories specified in the `-I' options
should be checked before the others, but I don't think that requires
their order to be reversed. Why doesn't autoconf simply read all the
`-I' options in order and prepend the complete list to the search
path? That's what existing tools do; for an example, try this:
perl -Ifoo -Ibar -Ibaz -e 'print join("\n", @INC) . "\n";'
It seems to me that this behavior would be much more intuitive and
wouldn't break anything. What does everyone else think about this?
Anyway, I should have explicitly mentioned the `-I' directories in my
summary of the search path. Here's what it should look like:
1. Directories specified with the `-I' option.
2. The current working directory ($top_srcdir).
3. Directories specified in the $AC_MACRO_PATH environment variable
(if set).
4. The system-wide site macro directory (set when autoconf is
installed).
Please let me know what you think.
--
Mark D. Roth <[EMAIL PROTECTED]>
http://www.feep.net/~roth/
