[Buildroot] [PATCH 4/5] toolchain-external: align library locations in target and staging dir

Arnout Vandecappelle arnout at mind.be
Sun Mar 27 20:34:24 UTC 2016


On 02/12/16 20:20, Thomas De Schampheleire wrote:
> From: Thomas De Schampheleire <thomas.de.schampheleire at gmail.com>
>
> The toolchain-external logic is roughly:
> - populate the staging dir by rsyncing the entire ${ARCH_LIB_DIR} and
>    usr/${ARCH_LIB_DIR} from sysroot.
> - populate the target dir by explictly copying some libraries from sysroot
>    into target/lib and some other libraries in target/usr/lib, the split
>    being hardcoded into buildroot regardless of the location in the sysroot.
>
> This means that a library libfoo could be located in:
>    staging/lib/libfoo.so
>    target/usr/lib/libfoo.so
>
> When debugging an application that links against this library, gdb will
> fruitlessly search for 'usr/lib/libfoo.so' in staging, and then suggest to
> use 'set solib-search-path' which is a hack, really.
>
> To solve the problem, we need to make sure that libraries from the toolchain
> are installed in the same relative location in staging and target.
> Achieve this by:
> - replacing the convoluted search for libraries using for+find in sysroot
>    with a simple find in staging.
> - determining DESTDIR for each library individually based on the location in
>    staging.
> - treating LIB_EXTERNAL_LIBS and USR_LIB_EXTERNAL_LIBS equivalently
>
> These changes also allow for the removal of most arguments to
> copy_toolchain_lib_root in the method itself and their callers.
>
> Test procedure:
> - set configuration for a given toolchain
> - make clean toolchain
> - find output/target | sort > /tmp/out-before
> - apply patch
> - make clean toolchain
> - find output/target | sort > /tmp/out-after
> - diff -u /tmp/out-before /tmp/out-after
>
> The only changes should be some libraries moving from lib to usr/lib or vice
> versa. Notable examples being libstdc++ and libatomic.
>
> Signed-off-by: Thomas De Schampheleire <thomas.de.schampheleire at gmail.com>

Acked-by: Arnout Vandecappelle (Essensium/Mind) <arnout at mind.be>

  Minor improvements below, but they could be separate patches.

> ---
>   package/glibc/glibc.mk                             |  2 +-
>   toolchain/helpers.mk                               | 57 ++--------------------
>   toolchain/toolchain-external/toolchain-external.mk | 39 ++++-----------
>   3 files changed, 15 insertions(+), 83 deletions(-)

  -65 net lines, that's the kind of patch I like!

>
> Test notes:
> I have executed the mentioned test procedure for all external toolchains
> listed on http://autobuild.buildroot.org/toolchains/configs/, for the x86
> ARMv7a Thumb2 EABIhf Linaro toolchain, and for an internal glibc toolchain.
> An x86_64 qemu image was booted, both with internal and external toolchain.
>
>
> diff --git a/package/glibc/glibc.mk b/package/glibc/glibc.mk
> index e60575f..bcec47f 100644
> --- a/package/glibc/glibc.mk
> +++ b/package/glibc/glibc.mk
> @@ -117,7 +117,7 @@ endif
>
>   define GLIBC_INSTALL_TARGET_CMDS
>   	for libs in $(GLIBC_LIBS_LIB); do \
> -		$(call copy_toolchain_lib_root,$(STAGING_DIR)/,,lib,$$libs,/lib) ; \
> +		$(call copy_toolchain_lib_root,$$libs) ; \
>   	done
>   endef
>
> diff --git a/toolchain/helpers.mk b/toolchain/helpers.mk
> index ee878e8..d5dc16f 100644
> --- a/toolchain/helpers.mk
> +++ b/toolchain/helpers.mk
> @@ -6,62 +6,15 @@
>   # toolchain logic, and the glibc package, so care must be taken when
>   # changing this function.
>   #
> -# Most toolchains (CodeSourcery ones) have their libraries either in
> -# /lib or /usr/lib relative to their ARCH_SYSROOT_DIR, so we search
> -# libraries in:
> -#
> -#  $${ARCH_LIB_DIR}
> -#  usr/$${ARCH_LIB_DIR}
> -#
> -# Buildroot toolchains, however, have basic libraries in /lib, and
> -# libstdc++/libgcc_s in /usr/<target-name>/lib(64), so we also need to
> -# search libraries in:
> -#
> -#  usr/$(TOOLCHAIN_EXTERNAL_PREFIX)/$${ARCH_LIB_DIR}
> -#
> -# Linaro toolchains have most libraries in lib/<target-name>/, so we
> -# need to search libraries in:
> -#
> -#  $${ARCH_LIB_DIR}/$(TOOLCHAIN_EXTERNAL_PREFIX)
> -#
> -# And recent Linaro toolchains have the GCC support libraries
> -# (libstdc++, libgcc_s, etc.) into a separate directory, outside of
> -# the sysroot, that we called the "SUPPORT_LIB_DIR", into which we
> -# need to search as well.
> -#
> -# Thanks to ARCH_LIB_DIR we also take into account toolchains that
> -# have the libraries in lib64 and usr/lib64.
> -#
> -# Please be very careful to check the major toolchain sources:
> -# Buildroot, Crosstool-NG, CodeSourcery and Linaro before doing any
> -# modification on the below logic.
> -#
> -# $1: arch specific sysroot directory
> -# $2: support libraries directory (can be empty)
> -# $3: library directory ('lib' or 'lib64') from which libraries must be copied
> -# $4: library name
> -# $5: destination directory of the libary, relative to $(TARGET_DIR)
> +# $1: library name
>   #
>   copy_toolchain_lib_root = \
> -	ARCH_SYSROOT_DIR="$(strip $1)"; \
> -	SUPPORT_LIB_DIR="$(strip $2)" ; \
> -	ARCH_LIB_DIR="$(strip $3)" ; \
> -	LIB="$(strip $4)"; \
> -	DESTDIR="$(strip $5)" ; \
> +	LIB="$(strip $1)"; \
>   \
> -	for dir in \
> -		$${ARCH_SYSROOT_DIR}/$${ARCH_LIB_DIR}/$(TOOLCHAIN_EXTERNAL_PREFIX) \
> -		$${ARCH_SYSROOT_DIR}/usr/$(TOOLCHAIN_EXTERNAL_PREFIX)/$${ARCH_LIB_DIR} \
> -		$${ARCH_SYSROOT_DIR}/$${ARCH_LIB_DIR} \
> -		$${ARCH_SYSROOT_DIR}/usr/$${ARCH_LIB_DIR} \
> -		$${SUPPORT_LIB_DIR} ; do \
> -		LIBPATHS=`find $${dir} -maxdepth 1 -name "$${LIB}" 2>/dev/null` ; \
> -		if test -n "$${LIBPATHS}" ; then \
> -			break ; \
> -		fi \
> -	done ; \
> -	mkdir -p $(TARGET_DIR)/$${DESTDIR}; \
> +	LIBPATHS=`find $(STAGING_DIR) -follow -name "$${LIB}" 2>/dev/null` ; \

  -follow is documented as depracated, use -L instead. But why do we need this? 
I tried without it and it seems to work just the same. I also don't think the 
error redirect is needed anymore (at least when the -follow is removed).


>   	for LIBPATH in $${LIBPATHS} ; do \
> +		DESTDIR=`echo $${LIBPATH} | sed "s,^$(STAGING_DIR)/,," | xargs dirname` ; \

  I would have written this as

DESTDIR=`echo $${LIBPATH} | sed "s,^$(STAGING_DIR)/\(.*\)/[^/]*,\1,"` ; \

but perhaps I'm too much of a regexp lover :-)

> +		mkdir -p $(TARGET_DIR)/$${DESTDIR}; \
>   		while true ; do \

  I wonder if the loop is still needed now. As far as I can see, the idea of 
this loop was to make sure that the library pointed to was also copied. But 
since we now copy everything even if it is not in the expected lib path, it 
shouldn't be needed anymore. Except if the library pointed to doesn't match the 
glob pattern we are searching for... Anyway, that's something for a separate patch.

>   			LIBNAME=`basename $${LIBPATH}`; \
>   			LIBDIR=`dirname $${LIBPATH}` ; \
> diff --git a/toolchain/toolchain-external/toolchain-external.mk b/toolchain/toolchain-external/toolchain-external.mk
> index d5445e5..a333c32 100644
> --- a/toolchain/toolchain-external/toolchain-external.mk
> +++ b/toolchain/toolchain-external/toolchain-external.mk
> @@ -585,24 +585,16 @@ endef
>   #                       our sysroot, and the directory will also be
>   #                       considered when searching libraries for copy
>   #                       to the target filesystem.
> +#
> +# Please be very careful to check the major toolchain sources:
> +# Buildroot, Crosstool-NG, CodeSourcery and Linaro
> +# before doing any modification on the below logic.
>
>   define TOOLCHAIN_EXTERNAL_INSTALL_TARGET_LIBS
> -	$(Q)ARCH_SYSROOT_DIR="$(call toolchain_find_sysroot,$(TOOLCHAIN_EXTERNAL_CC) $(TOOLCHAIN_EXTERNAL_CFLAGS))" ; \
> -	ARCH_LIB_DIR="$(call toolchain_find_libdir,$(TOOLCHAIN_EXTERNAL_CC) $(TOOLCHAIN_EXTERNAL_CFLAGS))" ; \
> -	SUPPORT_LIB_DIR="" ; \
> -	if test `find $${ARCH_SYSROOT_DIR} -name 'libstdc++.a' | wc -l` -eq 0 ; then \
> -		LIBSTDCPP_A_LOCATION=$$(LANG=C $(TOOLCHAIN_EXTERNAL_CC) $(TOOLCHAIN_EXTERNAL_CFLAGS) -print-file-name=libstdc++.a) ; \
> -		if [ -e "$${LIBSTDCPP_A_LOCATION}" ]; then \
> -			SUPPORT_LIB_DIR=`readlink -f $${LIBSTDCPP_A_LOCATION} | sed -r -e 's:libstdc\+\+\.a::'` ; \
> -		fi ; \
> -	fi ; \
> -	if test -z "$(BR2_STATIC_LIBS)" ; then \
> +	$(Q)if test -z "$(BR2_STATIC_LIBS)" ; then \

  This can now be converted into a make condition instead of a shell condition, 
which simplifies the logic even more. Well, actually, it could have been a make 
condition from the start because all of the above doesn't do anything except set 
some variables...


  Regards,
  Arnout

>   		$(call MESSAGE,"Copying external toolchain libraries to target...") ; \
> -		for libs in $(LIB_EXTERNAL_LIBS); do \
> -			$(call copy_toolchain_lib_root,$${ARCH_SYSROOT_DIR},$${SUPPORT_LIB_DIR},$${ARCH_LIB_DIR},$$libs,/lib); \
> -		done ; \
> -		for libs in $(USR_LIB_EXTERNAL_LIBS); do \
> -			$(call copy_toolchain_lib_root,$${ARCH_SYSROOT_DIR},$${SUPPORT_LIB_DIR},$${ARCH_LIB_DIR},$$libs,/usr/lib); \
> +		for libs in $(LIB_EXTERNAL_LIBS) $(USR_LIB_EXTERNAL_LIBS); do \
> +			$(call copy_toolchain_lib_root,$$libs); \
>   		done ; \
>   	fi
>   endef
> @@ -671,21 +663,8 @@ define TOOLCHAIN_EXTERNAL_INSTALL_SYSROOT_LIBS_BFIN_FDPIC
>   endef
>   define TOOLCHAIN_EXTERNAL_INSTALL_BFIN_FDPIC
>   	$(Q)$(call MESSAGE,"Install external toolchain FDPIC libraries to target...") ; \
> -	FDPIC_EXTERNAL_CC=$(dir $(TOOLCHAIN_EXTERNAL_CC))/../../bfin-linux-uclibc/bin/bfin-linux-uclibc-gcc ; \
> -	FDPIC_SYSROOT_DIR="$(call toolchain_find_sysroot,$${FDPIC_EXTERNAL_CC} $(TOOLCHAIN_EXTERNAL_CFLAGS))" ; \
> -	FDPIC_LIB_DIR="$(call toolchain_find_libdir,$${FDPIC_EXTERNAL_CC} $(TOOLCHAIN_EXTERNAL_CFLAGS))" ; \
> -	FDPIC_SUPPORT_LIB_DIR="" ; \
> -	if test `find $${FDPIC_SYSROOT_DIR} -name 'libstdc++.a' | wc -l` -eq 0 ; then \
> -	        FDPIC_LIBSTDCPP_A_LOCATION=$$(LANG=C $${FDPIC_EXTERNAL_CC} $(TOOLCHAIN_EXTERNAL_CFLAGS) -print-file-name=libstdc++.a) ; \
> -	        if [ -e "$${FDPIC_LIBSTDCPP_A_LOCATION}" ]; then \
> -	                FDPIC_SUPPORT_LIB_DIR=`readlink -f $${FDPIC_LIBSTDCPP_A_LOCATION} | sed -r -e 's:libstdc\+\+\.a::'` ; \
> -	        fi ; \
> -	fi ; \
> -	for libs in $(LIB_EXTERNAL_LIBS); do \
> -	        $(call copy_toolchain_lib_root,$${FDPIC_SYSROOT_DIR},$${FDPIC_SUPPORT_LIB_DIR},$${FDPIC_LIB_DIR},$$libs,/lib); \
> -	done ; \
> -	for libs in $(USR_LIB_EXTERNAL_LIBS); do \
> -	        $(call copy_toolchain_lib_root,$${FDPIC_SYSROOT_DIR},$${FDPIC_SUPPORT_LIB_DIR},$${FDPIC_LIB_DIR},$$libs,/usr/lib); \
> +	for libs in $(LIB_EXTERNAL_LIBS) $(USR_LIB_EXTERNAL_LIBS); do \
> +		$(call copy_toolchain_lib_root,$$libs); \
>   	done
>   endef
>   endif
>


-- 
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
GPG fingerprint:  7493 020B C7E3 8618 8DEC 222C 82EB F404 F9AC 0DDF


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