Re: Properly controlling CFLAGS/CXXFLAGS

Oliver Fromme wrote:
Garrett Cooper wrote:
> I was wondering (looking at the make.conf manpage), what's the
> best way to control one's CFLAGS/CXXFLAGS. I'd prefer if only a few
> ports would have optimized compiler flags, while the rest of the system
> used a safe set of compiler flags.

The simplest way is to use conditionals in /etc/make.conf
depending on the ports directory:

.if ${.CURDIR:M*/somecategory/someport}
CFLAGS= -O3 -pipe
CFLAGS+= -DSOMETHING
.endif

> CFLAGS= -O2 -pipe

Using -O2 without -fno-strict-aliasing will break certain
programs. The default is -O2 -fno-strict-aliasing -pipe
and it is _not_ recommended to override it globally, or
otherwise you're guaranteed to shoot yourself in the foot,
sooner or later.

> COPTFLAGS= ${CFLAGS} -msse -msse2 -mfpmath=sse,387

That will break kernel compiles. Again, you should not
override COPTFLAGS, unless you know exactly what you're
doing.

Best regards
Oliver

Interesting. No wonder I didn't have it in my Gentoo /etc/make.conf. It appears (from what I see) that maybe -fno-strict-aliasing has been enabled by default (at least it doesn't show up in the GCC 4.1.1 manpage on FC5).
-Garrett
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