Tuesday 30 May 2006 07:41 skrev Graham Murray: > > Besides, by looking at the terminal while merging packages, you will > > soon notice, that lot's of packages add their very own CFLAGS to your > > default ones. For example mplayer or xine-lib was compiled with '-O3' on > > my system, allthough i have '-O2' in my CFLAGS. (As far as i know, "gcc > > -O3 -O2" == "gcc -O3"). > > Where packages do this, should they not filter out the appropriate > flags from the user's CFLAGS and substitute their flags rather than > having both flags on the command line?
Not in this particular case. xine-lib is a good example. src_compile()
contains the following in the ebuild (and more):
if [[ $(tc-arch) == "x86" ]]; then
filter-flags -fforce-addr
filter-flags -momit-leaf-frame-pointer
is-flag -O? || append-flags -O2
fi
On an x86 architecture it filters out -fforce-addr
and -momit-leaf-frame-pointer. If the CFLAGS contain any optimizations it
just appends -O2 yielding that -O2 will be used as stated by Christian
Limberg. In 'man gcc' you find the following statement:
"If you use multiple -O options, with or without level numbers, the last such
option is the one that is effective."
So this is completely legal.
And I very much doubt that there are any ebuilds in the portage tree that
enforces -O3 or higher...
--
Bo Andresen
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