[Buildroot] [PATCH v6 08/13] core: add HOST_SANITIZE_RPATH_HOOK to TARGET_FINALIZE_HOOKS

[Arnout Vandecappelle <arnout@mind.be>]

On 01-02-16 16:53, Samuel Martin wrote:
> This patch adds host-patchelf as a target-finalize dependency, and
> introduces the HOST_SANITIZE_RPATH_HOOK hook to fix the ELF files'
> RPATH from the HOST_DIR location (excluding the sysroot).
> 
> After running this hook, the RPATH from any host ELF files is relative to
> the binary location itself.
> 
> Notes:
> - we avoid to fix RPATH in the sysroot.
> - we do not try to fix RPATH in the external toolchain installation
>   location as they may have been built in a way, this is already correct;
>   furthermore, fixing RPATH in those programs may result in breaking them.
> - the whole host directory is processed because a number of
>   host-package install programs that could be useful in places
>   different from $(HOST_DIR)/{bin,sbin,usr/bin,usr/sbin}.
> - the shared libraries are also processed in case they have a 'main'
>   function.
> 
> As a step toward a fully relocatable SDK, this change allows to get the
> toolchain relocatable, but not yet the whole SDK.
> 
> Signed-off-by: Samuel Martin <s.martin49@gmail.com>
> 
> ---
> changes v5->v6:
> - update for the new script version
> - add debug mode support
> 
> changes v4->v5:
> - add verbose support
> 
> changes v3->v4:
> - add host-patchelf to PACKAGES instead of target-finalize (Baruch)
> - add comment
> 
> changes v2->v3:
> - move hook in Makefile (Baruch)
> ---
>  Makefile | 25 +++++++++++++++++++++++++
>  1 file changed, 25 insertions(+)
> 
> diff --git a/Makefile b/Makefile
> index 7c87177..b1f4fcf 100644
> --- a/Makefile
> +++ b/Makefile
> @@ -616,6 +616,31 @@ endef
>  TARGET_FINALIZE_HOOKS += PURGE_LOCALES
>  endif
>  
> +# RPATH fixing
> +# - The host hook sets RPATH in host ELF binaries, using relative paths to the
> +#   library locations.
> +# - The target hook sanitizes RPATH in target ELF binaries, removing paths
> +#   pointing to package's build directories or the sysroot's libdirs.
> +PACKAGES += host-patchelf
> +
> +ifeq ($(BR2_DEBUG_RPATH),)
> +BR2_DEBUG_RPATH = 0
> +endif
> +ifeq ($(BR2_DEBUG_RPATH),0)
> +DEBUG_RPATH = 0
> +else
> +DEBUG_RPATH = $(shell echo $$(($(BR2_DEBUG_RPATH)+1)))
> +endif

 I don't like this debug handling in the Makefile. For the toolchain wrapper,
the BR2_DEBUG_WRAPPER variable is used directly in the wrapper, so nothing
specific has to be done in the Makefile. So here as well I'd prefer to use
BR2_DEBUG_RPATH in the scripts.

 Since the logging stuff is generic, you will indeed have to convert it to the
DEBUG variable in the fix-rpath script, but IMHO that's much more acceptable.

 Also, it should be sufficient to set DEBUG=${BR_DEBUG_RPATH}. If
BR2_DEBUG_RPATH is not set, the ${DEBUG:=0} in log.sh will set it to 0.


> +
> +define HOST_SANITIZE_RPATH_HOOK
> +	DEBUG=$(DEBUG_RPATH) \
> +	PATCHELF=$(HOST_DIR)/usr/bin/patchelf \
> +	READELF=readelf \

 That's already set by the scripts, and actually it's probably better if the
user has the possibility to override readelf.


> +		$(TOPDIR)/support/scripts/fix-rpath host $(HOST_DIR)

 I find this indentation a bit weird. But OK.

 Regards,
 Arnout

> +endef
> +
> +TARGET_FINALIZE_HOOKS += HOST_SANITIZE_RPATH_HOOK
> +
>  $(TARGETS_ROOTFS): target-finalize
>  
>  target-finalize: $(PACKAGES)
> 


-- 
Arnout Vandecappelle                          arnout at mind be
Senior Embedded Software Architect            +32-16-286500
Essensium/Mind                                http://www.mind.be
G.Geenslaan 9, 3001 Leuven, Belgium           BE 872 984 063 RPR Leuven
LinkedIn profile: http://www.linkedin.com/in/arnoutvandecappelle
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