Re: bin/49198: make not seeing all .SUFFIXES suffixes

[David Holland <dholland-bugs%netbsd.org@localhost>]

The following reply was made to PR bin/49198; it has been noted by GNATS.

From: David Holland <dholland-bugs%netbsd.org@localhost>
To: gnats-bugs%NetBSD.org@localhost
Cc: 
Subject: Re: bin/49198: make not seeing all .SUFFIXES suffixes
Date: Sat, 13 Sep 2014 01:30:40 +0000

 On Fri, Sep 12, 2014 at 01:50:01PM +0000, reed%reedmedia.net@localhost wrote:
  > TARGETS =       foo
  > all: ${TARGETS}
  > .SUFFIXES:
  > .SUFFIXES: .1 .2 .3 .4 .5 .6 .7 .8 .9 .a .b .py
  > .py:
  >         cp -f $< $@
  > 
  > With only the Makefile and foo.py in directory.
  > 
  > make: don't know how to make foo. Stop
  > make: stopped in /tmp/m
  > 
  > If I remove one suffix then it works. If I put the .py at the front it 
  > works.
 
 The problem is that when you do .SUFFIXES: it doesn't clear the graph
 connectivity of the magic empty suffix object. Then if the combination
 of circumstances is just so, when it goes to add .py to the empty
 suffix object at the bottom of Suff_AddTransform, the serial number of
 the new suffix .py matches the serial number of a stale suffix that's
 already there and it does nothing. Then of course it can't match .py
 after that.
 
 I am reluctant to patch this until we finish sorting out the
 backed-out suffix changes, because that will promote merge conflicts
 while doing so, but it should be reasonably straightforward to fix
 once that situation's more under control.
 
 -- 
 David A. Holland
 dholland%netbsd.org@localhost