Re: [PATCH 04/26] kbuild: introduce $(kecho) convenience echo

Vegard Nossum
2008-12-20T15:13:38Z

Hi,

On Sat, Dec 20, 2008 at 3:31 PM, Sam Ravnborg <sam@ravnborg.org> wrote:
> From: Mike Frysinger <vapier@gentoo.org>
>
> There is a bunch of places in the build system where we do 'echo' to show
> some nice status lines. This means we still get output when running in
> silent mode. So declare a new KECHO variable that only does 'echo' when we
> are in a suitable verbose build mode.
>
> Signed-off-by: Mike Frysinger <vapier@gentoo.org>
> [sam: added Documentation]
> Signed-off-by: Sam Ravnborg <sam@ravnborg.org>
> ---
> Documentation/kbuild/makefiles.txt | 14 ++++++++++++++
> scripts/Kbuild.include | 7 +++++++
> 2 files changed, 21 insertions(+), 0 deletions(-)
>
> diff --git a/Documentation/kbuild/makefiles.txt b/Documentation/kbuild/makefiles.txt
> index 7a77533..51104f9 100644
> --- a/Documentation/kbuild/makefiles.txt
> +++ b/Documentation/kbuild/makefiles.txt
> @@ -383,6 +383,20 @@ more details, with real examples.
> to prerequisites are referenced with $(src) (because they are not
> generated files).
>
> + $(kecho)
> + echoing information to user in a rule is often a good practice
> + but when execution "make -s" one does not expect to see any output
> + except for warnings/errors.
> + To support this kbuild define $(kecho) which will echo out the
> + text following $(kecho) to stdout except if "make -s" is used.
> +
> + Example:
> + #arch/blackfin/boot/Makefile
> + $(obj)/vmImage: $(obj)/vmlinux.gz
> + $(call if_changed,uimage)
> + @$(kecho) 'Kernel: $@ is ready'
> +
> +
> --- 3.11 $(CC) support functions
>
> The kernel may be built with several different versions of
> diff --git a/scripts/Kbuild.include b/scripts/Kbuild.include
> index 936940b..8cf87e8 100644
> --- a/scripts/Kbuild.include
> +++ b/scripts/Kbuild.include
> @@ -25,6 +25,13 @@ basetarget = $(basename $(notdir $@))
> escsq = $(subst $(squote),'\$(squote)',$1)
>
> ###
> +# Easy method for doing a status message
> + kecho := :
> + quiet_kecho := echo
> +silent_kecho := :
> +kecho := $($(quiet)kecho)

Hm, why don't we put

+kecho := @$($(quiet)kecho)

instead, so each caller can omit the @? And the example would then be:

> + $(obj)/vmImage: $(obj)/vmlinux.gz
> + $(call if_changed,uimage)
> + $(kecho) 'Kernel: $@ is ready'

It seems to work correctly over here.

Vegard

--
"The animistic metaphor of the bug that maliciously sneaked in while
the programmer was not looking is intellectually dishonest as it
disguises that the error is the programmer's own creation."
-- E. W. Dijkstra, EWD1036