[ng] vars: names for internal make variables: 'am.foo' and 'am.foo.bar-baz'

That is the new preferred naming scheme: 'am.foo' where we would
have previously used something like 'am__foo', and 'am.foo.bar-baz'
where we would have previously used something like 'am__foo_bar_baz'
or 'am__foo__bar_baz'.

We should start using the new naming to do so in future commits.  But
we should also avid a sweeping rename for now, to minimize conflicts
with the mainline Automake codebases, which (for portability reason)
must still limit itself to the use of the 'am__' prefix.

* HACKING: Adjust.  Also, remove now-irrelevant advice about the
problem of an old vendor make (NEWS-OS 4.2R) with variables whose
name start with an underscore.

Signed-off-by: Stefano Lattarini <stefano.lattarini@gmail.com>

diff --git a/HACKING b/HACKING
index c15718f550dcdfd99dbdf1d0ffab5b340b3bd5bb..03b9dd5288414c7467965f75ffa11f1ea52b4a8b 100644 (file)
--- a/HACKING
+++ b/HACKING
@@ -41,16 +41,17 @@
 ================================================================
 = Naming
 
-* We've adopted the convention that internal AC_SUBSTs should be
-  named with a leading 'am__', and internally generated targets
-  should be named with a leading 'am--'.  This convention, although
-  in place from at least February 2001, isn't yet universally used.
-  But all new code should use it.
-
-  We used to use '_am_' as the prefix for an internal AC_SUBST.
-  However, it turns out that NEWS-OS 4.2R complains if a Makefile
-  variable begins with the underscore character.  Yay for them.
-  I changed the target naming convention just to be safe.
+* Internal make variables and functions should be named following patterns
+  like 'am.tty-colors' or 'am.dist.files'.
+
+* Internal AC_SUBSTs should be named with a leading 'am__'.
+
+* Private make targets should be named with a leading 'am--'.
+
+* WARNING! This convention, introduced recently (since July 2012),
+  isn't yet universally used.  But all new code should use it,
+  except in those situation where that would cause spurious
+  conflicts with mainline Automake.
 
 ================================================================
 = Editing '.am' files