Messages in this thread | ![/](/images/icornerl.gif) | | From | Masahiro Yamada <> | Date | Mon, 19 Jun 2023 00:50:48 +0900 | Subject | Re: [PATCH] kbuild: make clean rule robust against too long argument error |
| |
On Sun, Jun 18, 2023 at 5:07 AM Eugeniu Rosca <erosca@de.adit-jv.com> wrote: > > Hello Yamada-san, > > Many thanks for your feedback and for your patch. > It indeed addresses the issue I have reported in [1]. > > On Sun, Jun 18, 2023 at 12:30:25AM +0900, Masahiro Yamada wrote: > > Commit cd968b97c492 ("kbuild: make built-in.a rule robust against too > > long argument error") made a build rule robust against "Argument list > > too long" error. > > > > Eugeniu Rosca reported the same error occurred when cleaning an external > > module. > > > > The $(obj)/ prefix can be a very long path for external modules. > > Confirmed. I am seeing an instance of $(obj) being 150 characters long, > due to an out-of-tree module deeply buried in a specific Yocto build. > > In the current vanilla version of 'make clean' (w/o this patch), the > $(obj) prefix is applied to each and every file being removed, > dramatically increasing the strlen of arguments passed to 'rm -rf'. > > > > > Apply a similar solution to 'make clean'. > > > > Reported-by: Eugeniu Rosca <erosca@de.adit-jv.com> > > Signed-off-by: Masahiro Yamada <masahiroy@kernel.org> > > --- > > > > scripts/Makefile.clean | 3 ++- > > 1 file changed, 2 insertions(+), 1 deletion(-) > > > > diff --git a/scripts/Makefile.clean b/scripts/Makefile.clean > > index 3649900696dd..235408a44f90 100644 > > --- a/scripts/Makefile.clean > > +++ b/scripts/Makefile.clean > > @@ -37,8 +37,9 @@ __clean-files := $(wildcard $(addprefix $(obj)/, $(__clean-files))) > > > > # ========================================================================== > > > > +# Use xargs to make this robust against "Argument list too long" error > > Please, correct me if I am wrong, but it looks like the magic/brilliance > is in the 'patsubst' function, since below version also fails for me: > > NOK: cmd_clean = printf '%s ' $(__clean-files) | xargs rm -rf
Right. Now, 'printf' (instead of 'rm') failed with the too long argument list.
GNU Make does not have the length limit, but shell does. So, the full-path list must be passed via stdout instead of the command line.
The comment might be confusing.
I will repeat the same comment written in scripts/Makefile.build:
# To make this rule robust against "Argument list too long" error, # remove $(obj)/ prefix, and restore it by a shell command.
-- Best Regards Masahiro Yamada
| ![\](/images/icornerr.gif) |