Re: using target-specific variables?

[Ralf Wildenhues]

* Stepan Kasal wrote on Thu, May 12, 2005 at 02:57:46PM CEST:
> On Thu, May 12, 2005 at 02:02:54PM +0200, Ralf Wildenhues wrote:
> > * Harald Dunkel wrote on Thu, May 12, 2005 at 01:43:51PM CEST:
> > > Anyway, if I introduce a line
> > > 
> > >   myexe: some_internal_tool_used_at_build_time
> > > 
> > > then Automake shows the same misbehaviour: It assumes that
> > > I would like to redefine the build rule for myexe.
> 
> well, this behaviour is documented in the Automake manual,
> in node ``Extending'':
> 
> :    Note that Automake does not make any difference between rules with
> : commands and rules that only specify dependencies.  So it is not
> : possible to append new dependencies to an `automake'-defined target
> : without redefining the entire rule.

ACK.

> But Ralf said:
> 
> > Well, that's just how `make' syntax works (portable make != GNU make).
> 
> You mean that some make implementations don't allow you to specify extra
> dependencies in a rule with no commands (so called "separated
> dependencies")?

Nono, I did not mean that (but now that you point it out I see that I
missed the fact that his line quoted above looks differently from
before).  Harald had, in one of his previous posts, a line like this:
  target: CC=gcc3

and obviously, `CC=gcc3' was not intended to be a dependency of
`target', but some kind of syntax to change a variable esp. for the
rules of updating `target'.  *This* intended behavior is a broken
assumption.

> I'm not convinced about this.  Node "(autoconf.info)Limitations of Make"
> speaks about problems when you combine separated dependencies with so
> called "single suffix rules".  But generally, separated dependencies
> should work.

Sure.  Thanks for clarifying this point.

Regards,
Ralf