Re: Add support for generating HTML docs a` la PDF, etc., revision 2

[Alexandre Duret-Lutz]

>>> "Ralf" == Ralf Corsepius <address@hidden> writes:

 Ralf> Eg. I have one Makefile.am using this:

 Ralf> html:
 Ralf>         mkdir html

I think we face the same problem every time Automake introduces
a new target: collision with existing targets.  For instance
Automake 1.7 introduced `ctags', `ps', and `pdf', so now you
can't build any programs with these names.  Now you couldn't
build a program named `html' either.

As far as programs are concerned, PR/344 gives a workaround.
Simple rules like your `html:', seems easier to fix.  Richard
suggested a rewrite which is close to what Automake already does
when it has to create directory:

sub/$(am__dirstamp):
        @$(mkinstalldirs) sub
        @: > sub/$(am__dirstamp)

sub/foo.$(OBJEXT): sub/$(am__dirstamp) ...

(AFAICT, Automake proceeds this way so that the directory 
is created in `.' even if it already exists in `$(srcdir)'.)

Sure, having to revise one's Makefile.am on Automake upgrades is
a pain.  I don't really see what else we could do.  (Never
introducing new targets doesn't look like a solution to me.)  It
sounds like we ought have diagnostics to help the transition by
spotting such troublesome rules.  How would we catch these?
Right now the only thing I can think of is to add something
like: 
  -Woverride Warn when a user rule override an Automake rule

Any other idea?
-- 
Alexandre Duret-Lutz