Re: Prefer AM_CPPFLAGS to @CPPFLAGS@

[Ralf Wildenhues]

Hello Stepan, Eric, all,

* Eric Blake wrote on Fri, Jun 22, 2007 at 02:54:05PM CEST:
> According to Stepan Kasal on 6/11/2007 4:47 AM:
> > On Sun, Jun 10, 2007 at 09:13:14AM +0200, Ralf Wildenhues wrote:
> >>> -CPPFLAGS = -DDATADIR='"$(datadir)"' @@CPPFLAGS@@
> >>> +AM_CPPFLAGS = -DDATADIR='"$(datadir)"'
> >> Why not show both (the non-Automake case is useful and conveys
> >> additional information)?
> > 
> > A nice idea, but:
> > 
> > It would make the node too complex.

With due respect, I think it's possible to avoid complexity here.

> > The node "19.5 How Do I `#define' Installation Directories?" is in
> > the FAQ section, so people might expect it is short.
> 
> True, but AM_CPPFLAGS is not provided by autoconf, and autoconf can be run
> independently of automake.  I think we should either provide both
> examples, or at least provide a clear disclaimer that this example only
> works if you also use Automake, along with a pointer to somewhere else in
> the manual on how to do it when avoiding automake.

ACK.  And before adding pointers and the like all along, here's a patch
to just provide both information with one additional sentence.  OK?

Cheers,
Ralf

2007-08-21  Stepan Kasal  <address@hidden>
            Ralf Wildenhues  <address@hidden>

        * doc/autoconf.texi (Defining Directories): Mention
        AM_CPPFLAGS, as the way to modify CPPFLAGS when using Automake.

Index: doc/autoconf.texi
===================================================================
RCS file: /cvsroot/autoconf/autoconf/doc/autoconf.texi,v
retrieving revision 1.1165
diff -u -r1.1165 autoconf.texi
--- doc/autoconf.texi   20 Aug 2007 21:29:36 -0000      1.1165
+++ doc/autoconf.texi   21 Aug 2007 17:57:56 -0000
@@ -19170,7 +19170,14 @@
 @end example
 
 @noindent
-or create a dedicated header file:
+If you use Automake, you should use @code{AM_CPPFLAGS} instead:
+
address@hidden
+AM_CPPFLAGS = -DDATADIR='"$(datadir)"'
address@hidden example
+
address@hidden
+Alternatively, create a dedicated header file:
 
 @example
 DISTCLEANFILES = datadir.h