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author | Masahiro Yamada <masahiroy@kernel.org> | 2021-05-17 10:03:13 +0300 |
---|---|---|
committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2021-07-25 15:35:11 +0300 |
commit | e79e29a4e162dd549d30794d45e38400573f0cdc (patch) | |
tree | 2c88d15b1f9b895259a3551641b798806c3c9154 /scripts | |
parent | f817d4677582b297ee5897afd84b25aa2f7c2d62 (diff) | |
download | linux-e79e29a4e162dd549d30794d45e38400573f0cdc.tar.xz |
kbuild: sink stdout from cmd for silent build
[ Upstream commit 174a1dcc96429efce4ef7eb2f5c4506480da2182 ]
When building with 'make -s', no output to stdout should be printed.
As Arnd Bergmann reported [1], mkimage shows the detailed information
of the generated images.
I think this should be suppressed by the 'cmd' macro instead of by
individual scripts.
Insert 'exec >/dev/null;' in order to redirect stdout to /dev/null for
silent builds.
[Note about this implementation]
'exec >/dev/null;' may look somewhat tricky, but this has a reason.
Appending '>/dev/null' at the end of command line is a common way for
redirection, so I first tried this:
cmd = @set -e; $(echo-cmd) $(cmd_$(1)) >/dev/null
... but it would not work if $(cmd_$(1)) itself contains a redirection.
For example, cmd_wrap in scripts/Makefile.asm-generic redirects the
output from the 'echo' command into the target file.
It would be expanded into:
echo "#include <asm-generic/$*.h>" > $@ >/dev/null
Then, the target file gets empty because the string will go to /dev/null
instead of $@.
Next, I tried this:
cmd = @set -e; $(echo-cmd) { $(cmd_$(1)); } >/dev/null
The form above would be expanded into:
{ echo "#include <asm-generic/$*.h>" > $@; } >/dev/null
This works as expected. However, it would be a syntax error if
$(cmd_$(1)) is empty.
When CONFIG_TRIM_UNUSED_KSYMS is disabled, $(call cmd,gen_ksymdeps) in
scripts/Makefile.build would be expanded into:
set -e; { ; } >/dev/null
..., which causes an syntax error.
I also tried this:
cmd = @set -e; $(echo-cmd) ( $(cmd_$(1)) ) >/dev/null
... but this causes a syntax error for the same reason.
So, finally I adopted:
cmd = @set -e; $(echo-cmd) exec >/dev/null; $(cmd_$(1))
[1]: https://lore.kernel.org/lkml/20210514135752.2910387-1-arnd@kernel.org/
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
Diffstat (limited to 'scripts')
-rw-r--r-- | scripts/Kbuild.include | 7 |
1 files changed, 6 insertions, 1 deletions
diff --git a/scripts/Kbuild.include b/scripts/Kbuild.include index 7da10afc92c6..b14a7d4a2f05 100644 --- a/scripts/Kbuild.include +++ b/scripts/Kbuild.include @@ -182,8 +182,13 @@ clean := -f $(srctree)/scripts/Makefile.clean obj echo-cmd = $(if $($(quiet)cmd_$(1)),\ echo ' $(call escsq,$($(quiet)cmd_$(1)))$(echo-why)';) +# sink stdout for 'make -s' + redirect := + quiet_redirect := +silent_redirect := exec >/dev/null; + # printing commands -cmd = @set -e; $(echo-cmd) $(cmd_$(1)) +cmd = @set -e; $(echo-cmd) $($(quiet)redirect) $(cmd_$(1)) ### # if_changed - execute command if any prerequisite is newer than |