document what each LFS flag does exactly

diff --git a/eclass/flag-o-matic.eclass b/eclass/flag-o-matic.eclass
index 2fec315b02a63db9045e5f91b9312aeb60ab8b8e..e119e1be2ed0acd6d163a6b1245dd57890e38e40 100644 (file)
--- a/eclass/flag-o-matic.eclass
+++ b/eclass/flag-o-matic.eclass
@@ -1,6 +1,6 @@
 # Copyright 1999-2009 Gentoo Foundation
 # Distributed under the terms of the GNU General Public License v2
-# $Header: /var/cvsroot/gentoo-x86/eclass/flag-o-matic.eclass,v 1.152 2011/07/12 04:08:52 vapier Exp $
+# $Header: /var/cvsroot/gentoo-x86/eclass/flag-o-matic.eclass,v 1.153 2011/08/17 17:54:48 vapier Exp $
 
 # @ECLASS: flag-o-matic.eclass
 # @MAINTAINER:
@@ -131,6 +131,10 @@ filter-flags() {
 # Remove flags that enable Large File Support.
 filter-lfs-flags() {
        [[ -n $@ ]] && die "filter-lfs-flags takes no arguments"
+       # http://www.gnu.org/s/libc/manual/html_node/Feature-Test-Macros.html
+       # _LARGEFILE_SOURCE: enable support for new LFS funcs (ftello/etc...)
+       # _LARGEFILE64_SOURCE: enable support for 64bit variants (off64_t/fseeko64/etc...)
+       # _FILE_OFFSET_BITS: default to 64bit variants (off_t is defined as off64_t)
        filter-flags -D_FILE_OFFSET_BITS=64 -D_LARGEFILE_SOURCE -D_LARGEFILE64_SOURCE
 }