Re: AM_CONDITIONAL and config.status

[Tom Tromey]

>>>>> "Roger" == Roger Leigh <address@hidden> writes:

Roger> in Makefile.in, is it safe to use this format in my own .in files (e.g.
Roger> po/POTFILES.in), or will the format used for the conditionals in .in
Roger> files change at a future date?  What I need to do is have lines
Roger> conditionally included, as some are conditionally distributed.

Conditionals don't work they way you seem to think they do.
The @FOO_TRUE@ is rewritten to either `' (empty string) or `#' (make
comment) by configure.  No line is omitted from the generated Makefile.

My recommendation is not to rely on the implementation of
conditionals.  It isn't something we have ever documented.  We might
actually change it at some point; for instance we might be able to get
better performance from config.status if we change how conditionals
are implemented.

Roger> if COND
Roger> FOO
Roger> BAR
Roger> BAZ
Roger> else
Roger> BAD
Roger> endif

I read this example but I don't understand how it differs from what we
already do.  Right now you can enclose all kinds of stuff in a single
conditional.  What you can't do is have a conditional that starts or
ends in the middle of a rule or macro definition.

Roger> Being able to use 'ifndef' would also be another nice addition,
Roger> or has this already been done (I possibly remember this being
Roger> mentioned).

You can use `if !FOO'.

Tom