On Fri, Jan 8, 2016 at 12:31 PM, Michal Marek <mmarek@xxxxxxx> wrote: > On 2016-01-08 11:03, Sedat Dilek wrote: >> On Mon, Jan 4, 2016 at 11:37 PM, Michal Marek <mmarek@xxxxxxx> wrote: >>> Dne 4.1.2016 v 12:47 Sedat Dilek napsal(a): >>>> But I think you did not get my problem - to have two different >>>> optimization-levels for a compiler in *one* make-line makes no sense >>>> to me. >>> >>> That we sometimes have -O2 ... -Os on the command line is not a problem, >>> since any same unix tool parses its options so that the last one of >>> mutually exclusive options wins. >> >> That is new to me and I haven't tested this by dropping arguments in >> my make-line(s). >> >> From where do have this information - sort of "business-life-experience" :-)? >> Is that documented somewhere in the Linux-sources? > > You override a previously set option by appending one with different value: > > $ yes | head -n 10 -n 999 -n 2 > y > y > $ > > This pattern is used all over in Makefiles. > > >> Do you agree that it is confusing to have two optlevel arguments in >> one make-line? > > It probably is, but fixing this problem would make the Makefiles unreadable. > > >> Linus suggested me to use a wrapper-script in case of using two >> different compiler and passing arguments... >> >> [ /usr/bin/mycompiler ] >> #!/bin/bash >> >> gcc-4.9 "$@" >> - EOF - >> >> According to your statement passing an optlevel here in this script >> will never-ever be recognized - as it is at the begin-of-(make)-line. > > Pass it as the last argument. > How do I do that? - Sedat - > >> So how should someone change the Linux-sources to test a different >> optlevel than -O2? > > make KCFLAGS=-O3 > > However, per-directory and per-file cflags set in Makefiles will take > precedence. If you want to override these as well, use the wrapper. > > Michal -- To unsubscribe from this list: send the line "unsubscribe linux-kbuild" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
