Re: Get rid of `-g' in CXXFLAGS

[Guido Draheim]

Braden McDaniel wrote:
> On Fri, 2003-08-01 at 23:44, Harlan Stenn wrote:
>
> > It's not that hard to get rid of a flag.
> >
> > nCFLAGS=
> > for i in $CFLAGS
> > do
> >   case "$i" in
> >     -g) ;;
> >     *) nCFLAGS="$nCFLAGS $i" ;;
> >   esac
> > done
> > CFLAGS=nCFLAGS
>
>
> That will also purge -g if it was added explicitly by the user.


WTF *aaaaaaaaaaaaaaaaarrrrrrgh* did anyone try the excercise? Anyone?

Okay, since it seems not to be the case these days to follow advise,
here is the breakdown of it:

IF you write `configure "CXXFLAGS="` THEN
   you will see that "-g -O2" was _not_ added as default to C(XX)FLAGS

WHAT do we learn from it? Those defaults are only applied when the
user did _not_ explicitly set some flags at configure time.

What leads that to? It *IS* possible to change the behavior of the
AC_PROG_(CC|CXX) macro by making sure the C(XX)FLAGS are *set* before.

How to do that? Before implanting the AC_PROG_(CC|CXX) macro into
the configure.ac script, write something like

test ".$CXXFLAGS" = "." && CXXFLAGS=""

Note however that also the default of "-O2" for gcc is being
spilled as well. So you may need to add that later on. If you
need an example to copy&paste, use this:

test ".$CFLAGS" = "." && CFLAGS=""
AC_PROG_CC
test ".$CFLAGS" = "." && test "$GCC" = "yes" && CFLAGS="-O3"

end of thread.
-- guido                                http://AC-Archive.sf.net
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