Re: [UNIKRAFT PATCH] build: Fix "Argument list too long" problem

[Simon Kuenzer <simon.kuenzer@xxxxxxxxx>]

Hi Cyril,

thanks a lot for this nice and useful work-around. I will take it upstream.

Thanks,

Simon

Reviewed-by: Simon Kuenzer <simon.kuenzer@xxxxxxxxx>

On 10.04.20 11:09, Cyril Soldani wrote:
> For libraries with lots of object files, such as musl, `make clean` was
> failing with "make: execvp: /bin/sh: Argument list too long" on some
> machines (depending on default maximum command-line length).
>
> The user could not solve this problem by changing his shell limits,
> because GNU make resets those to system defaults.
>
> This patch removes the direct call to `rm`, and replace it with a call
> to `xargs rm`, using an intermediate file generated by `make`. The
> intermediate file is kept after `clean` so that the user can inspect
> which files have been removed.
>
> Signed-off-by: Cyril Soldani <cyril.soldani@xxxxxxxxx>
> ---
>   Makefile                     | 1 +
>   support/build/Makefile.rules | 9 +++++++--
>   2 files changed, 8 insertions(+), 2 deletions(-)
>
> diff --git a/Makefile b/Makefile
> index be8fa8ce..e2b41457 100644
> --- a/Makefile
> +++ b/Makefile
> @@ -262,6 +262,7 @@ MV    := mv -f
>   CP    := cp -f
>   MKDIR := mkdir
>   TOUCH := touch
> +XARGS := xargs
>   
>   # kconfig uses CONFIG_SHELL
>   CONFIG_SHELL := $(SHELL)
> diff --git a/support/build/Makefile.rules b/support/build/Makefile.rules
> index 8c096fa5..fbdbc2c5 100644
> --- a/support/build/Makefile.rules
> +++ b/support/build/Makefile.rules
> @@ -779,8 +779,13 @@ endef
>   # cleanrule_lib $libname
>   define cleanrule_lib =
>   clean-$(1):
> -       $(call verbose_cmd,CLEAN,$(1),$(RM) \
> -       $($(call vprefix_lib,$(1),CLEAN-y)) $($(call vprefix_lib,$(1),CLEAN)))
> +       $(file >$(BUILD_DIR)/$(1)/uk_clean_list) \
> +            $(foreach O,$($(call vprefix_lib,$(1),CLEAN-y)),\
> +                $(file >>$(BUILD_DIR)/$(1)/uk_clean_list,$O)) \
> +            $(foreach O,$($(call vprefix_lib,$(1),CLEAN)),\
> +                $(file >>$(BUILD_DIR)/$(1)/uk_clean_list,$O))
> +       $(call verbose_cmd,CLEAN,$(1),\
> +            $(XARGS) $(RM) <$(BUILD_DIR)/$(1)/uk_clean_list)
>   
>   .PHONY: clean-$(1)
>   endef