[Bug-gforth] [bug #46722] Makefile rule to avod excess rebuilds has the opposite effect

[anonymous]

URL:
  <http://savannah.gnu.org/bugs/?46722>

                 Summary: Makefile rule to avod excess rebuilds has the
opposite effect
                 Project: Gforth
            Submitted by: None
            Submitted on: Sa 19 Dez 2015 18:09:25 UTC
                Category: None
                Severity: 3 - Normal
              Item Group: None
                  Status: None
                 Privacy: Public
             Assigned to: None
             Open/Closed: Open
         Discussion Lock: Any

    _______________________________________________________

Details:

The rule that tries to avoid changing the "version" file is just wrong.

As-is, whenever you change Makefile.in (without touching the version number
itself), you end up in a situation where "version" is older than
"Makefile.in", and <b>stays that way</b>, because the rule didn't actually
update "version".  But since the rule is there, and ran a command, GNU make
(at least) will assume that version is now brand-new (without checking again),
and therefore cause all the rules depending on "version" to re-trigger.  And
because the timestamp on "version" never becomes newer than that of
"Makefile.in", it'll keep on doing that on every "make" run, indefinitely.

So instead of saving one rebuild per change to Makefile.in, it triggers an
unlimited number of them, as soon as Makefile.in is ever touched.




    _______________________________________________________

Reply to this item at:

  <http://savannah.gnu.org/bugs/?46722>

_______________________________________________
  Nachricht gesendet von/durch Savannah
  http://savannah.gnu.org/