Subject: Re: kern/21311: Generic kernel doesnt compile in 1.6.1_STABLE
To: Lubomir Sedlacik <>
From: Mipam <>
List: netbsd-bugs
Date: 04/25/2003 01:12:04

> > I saw it, but i think something needs to change then.  Then what is
> > the difference between setting: CFLAGS+= -pipe and CFLAGS=-pipe ??
> > Same for COPTS?  I thought .... += means to add and = means to set.
> > What you tell me now is that it makes no difference anyway.  Both +=
> > and = SETS the options. So it makes me wonder again, whats the use of
> > += anyway if the options are set by += instead of adding something
> > above the by default defined options like -O2 in for example?
> the order depends.  there is no difference between CFLAGS+=, CFLAGS= or
> CFLAGS?= if it's the first one exapanded.  see make(1) for details.

interesting, i didnt know this.
The problem is i dont want to set CFLAGS by just adding -O2.
I think sometimes more options are set besides just -O2 and -pipe
so setting CFLAGS is a bad idea. Question would be: how
to put it so that the order is changed and that
by setting CFLAGS+=-pipe, -pipe is actually added instead of being
set as option? Or should i use := instead of +=?
However, i am more reluctant in doing so because in math this
notation means to actually define a variable and that's not what i wish.
Any suggestions?