[Buildroot] [PATCH v3 02/14] Move $(HOST_DIR)/usr/lib to $(HOST_DIR)/lib

[Romain Naour]

Hi Arnout,

Le 04/07/2017 à 16:03, Arnout Vandecappelle (Essensium/Mind) a écrit :
> This is a step towards eliminating $(HOST_DIR)/usr. It allows us to
> convert all packages installing things into $(HOST_DIR)/usr/lib without
> affecting the rest.
> 
> To allow compatibility with packages that still use $(HOST_DIR)/usr as
> the prefix, create a symlink from usr/lib to ../lib.
> 
> Note that the symlink creation will break when $(HOST_DIR)/usr/lib
> already exists as a directory, i.e. when rebuilding in an existing
> output directory. This is necessary: if we don't break it now, the
> following commits (which remove the usr part from various variables)
> _will_ break it.
> 
> At the same time as creating this symlink, we also have to update the
> check-host-rpath to accept both $(HOST_DIR)/usr/lib and $(HOST_DIR)/lib,
> because depending on how the package derives the path, it may be
> different.
> 
> Since there are some dependency chains that involve $(STAGING_DIR),
> $(STAGING_DIR) may in fact be created before $(HOST_DIR). Since
> $(STAGING_DIR) is a subdirectory of $(HOST_DIR), it is possible that the
> newly added rule for $(HOST_DIR) never triggers. To make sure that the
> rule does trigger, add an order-only dependency from $(STAGING_DIR) to
> $(HOST_DIR).
> 
> Signed-off-by: Arnout Vandecappelle (Essensium/Mind) <arnout at mind.be>

Reviewed-by: Romain Naour <romain.naour at smile.fr>

Best regards,
Romain

> ---
> v2: rebase on modifications of check-host-rpath with $ORIGIN.
> ---
>  Makefile                         | 10 +++++++---
>  support/scripts/check-host-rpath |  8 +++++---
>  2 files changed, 12 insertions(+), 6 deletions(-)
> 
> diff --git a/Makefile b/Makefile
> index a0f9f62771..ac349a79e8 100644
> --- a/Makefile
> +++ b/Makefile
> @@ -237,7 +237,7 @@ LEGAL_REPORT = $(LEGAL_INFO_DIR)/README
>  # dependencies anywhere else
>  #
>  ################################################################################
> -$(BUILD_DIR) $(TARGET_DIR) $(HOST_DIR) $(BINARIES_DIR) $(LEGAL_INFO_DIR) $(REDIST_SOURCES_DIR_TARGET) $(REDIST_SOURCES_DIR_HOST):
> +$(BUILD_DIR) $(TARGET_DIR) $(BINARIES_DIR) $(LEGAL_INFO_DIR) $(REDIST_SOURCES_DIR_TARGET) $(REDIST_SOURCES_DIR_HOST):
>  	@mkdir -p $@
>  
>  BR2_CONFIG = $(CONFIG_DIR)/.config
> @@ -552,11 +552,15 @@ prepare: $(BUILD_DIR)/buildroot-config/auto.conf
>  .PHONY: world
>  world: target-post-image
>  
> +# When creating HOST_DIR, also symlink usr/lib -> ../lib
> +$(HOST_DIR):
> +	@mkdir -p $@/usr $@/lib
> +	@ln -snf ../lib $@/usr/lib
> +
>  # Populating the staging with the base directories is handled by the skeleton package
> -$(STAGING_DIR):
> +$(STAGING_DIR): | $(HOST_DIR)
>  	@mkdir -p $(STAGING_DIR)
>  	@ln -snf $(STAGING_DIR) $(BASE_DIR)/staging
> -	@mkdir -p $(HOST_DIR)/usr
>  	@ln -snf ../$(GNU_TARGET_NAME) $(HOST_DIR)/usr/$(GNU_TARGET_NAME)
>  
>  RSYNC_VCS_EXCLUSIONS = \
> diff --git a/support/scripts/check-host-rpath b/support/scripts/check-host-rpath
> index 020c12379f..adabfdf53f 100755
> --- a/support/scripts/check-host-rpath
> +++ b/support/scripts/check-host-rpath
> @@ -1,7 +1,7 @@
>  #!/usr/bin/env bash
>  
> -# This script scans $(HOST_DIR)/{bin,sbin} for all ELF files, and checks
> -# they have an RPATH to $(HOST_DIR)/usr/lib if they need libraries from
> +# This script scans $(HOST_DIR)/{,usr/}{bin,sbin} for all ELF files, and checks
> +# they have an RPATH to $(HOST_DIR)/{,usr/}lib if they need libraries from
>  # there.
>  
>  # Override the user's locale so we are sure we can parse the output of
> @@ -40,7 +40,7 @@ elf_needs_rpath() {
>      local lib
>  
>      while read lib; do
> -        [ -e "${hostdir}/usr/lib/${lib}" ] && return 0
> +        [ -e "${hostdir}/lib/${lib}" ] && return 0
>      done < <( readelf -d "${file}"                                         \
>                |sed -r -e '/^.* \(NEEDED\) .*Shared library: \[(.+)\]$/!d;' \
>                       -e 's//\1/;'                                          \
> @@ -58,6 +58,8 @@ check_elf_has_rpath() {
>          for dir in ${rpath//:/ }; do
>              # Remove duplicate and trailing '/' for proper match
>              dir="$( sed -r -e 's:/+:/:g; s:/$::;' <<<"${dir}" )"
> +            [ "${dir}" = "${hostdir}/lib" -o "${dir}" = "\$ORIGIN/../lib" ] && return 0
> +            # For the time being, the rpath is allowed with both usr/lib and lib
>              [ "${dir}" = "${hostdir}/usr/lib" -o "${dir}" = "\$ORIGIN/../../usr/lib" ] && return 0
>          done
>      done < <( readelf -d "${file}"                                              \
>