[Buildroot] [PATCH v12 3/3] toolchain-external: create symlink ARCH_LIB_DIR->lib

[Romain Naour <romain.naour@gmail.com>]

Hi Thomas,

Le 28/01/2016 13:32, Thomas De Schampheleire a ?crit :
> From: Thomas De Schampheleire <thomas.de.schampheleire@gmail.com>
> 
> Currently, following symbolic links are created in both target and
> staging directories:
> - lib(32|64) --> lib
> - usr/lib(32|64) --> lib
> 
> The decision for lib32 or lib64 is based on the target architecture
> configuration in buildroot (BR2_ARCH_IS_64).
> 
> In at least one case this is not correct: when building for a Cavium Octeon
> III processor using the toolchain from the Cavium Networks SDK, and
> specifying -march=octeon3 in BR2_TARGET_OPTIMIZATION, libraries are expected
> in directory 'lib32-fp' rather than 'lib32' (ABI=n32; likewise for
> lib64-fp in case of ABI=n64)
> 
> More generally the correct symbolic link is from (usr/)${ARCH_LIB_DIR}->lib.
> However, feedback from Arnout Vandecappelle is that there are packages that
> do depend on the lib32/lib64 symlink, even if ARCH_LIB_DIR is different.
> Hence, these links must be kept.
> 
> Fix the problem as follows:
> - For internal toolchains: no change
> - For external toolchains: create a symlink ARCH_LIB_DIR->lib if
>   (usr/)ARCH_LIB_DIR does not exist yet.
> 
> Signed-off-by: Thomas De Schampheleire <thomas.de.schampheleire@gmail.com>
> Cc: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>
> Cc: Arnout Vandecappelle <arnout@mind.be>
> Cc: "Yann E. Morin" <yann.morin.1998@free.fr>
> Cc: Romain Naour <romain.naour@gmail.com>
> Cc: Peter Korsgaard <peter@korsgaard.com>

Thanks for this new version!

Reviewed-by: Romain Naour <romain.naour@gmail.com>
Tested-by: Romain Naour <romain.naour@gmail.com>

Best regards,
Romain

> 
> ---
> v12:
> - 'test -e' instead of 'test -f' to avoid broken symlinks lib->lib
>   (noticed by Romain)
> v11:
> - check for existence of destination instead of explicitly checking on the
>   known values lib/lib32/lib64. (ThomasP)
> v10:
> - simplify after realization that skeleton symlink creation can be kept
>   (thanks Thomas Petazzoni for noticing this)
> v9:
> - remove redundant mkdir's (handled by skeleton) (Yann)
> v8:
> - use helper only for external toolchain and incorporate ARCH_LIB_DIR
>   definition (Arnout)
> - keep lib32/lib64->lib symlink anyway
> v7: rebase
> v6: rebase only
> v5:
> - move internal toolchain logic into gcc-initial.mk
> - also silence the internal toolchain link steps with $(Q)
> v4:
> - merge both helpers into one
> - remove the separate target for the internal toolchain and hook into
>   gcc-initial
> - re-add deleted comment about MIPS64/n32
> v3:
> - update commit message wrapping
> - change dependency on $(BUILD_DIR) to a order-only dependency
> v2:
> - fix 'lib32-fp' leftover in toolchain-buildroot
> - silence commands creating symlink with $(Q)
> - fix case where ARCH_LIB_DIR is 'lib'
> 
> Note: in output/staging/usr/ there would still be more directories than I
> think are really necessary. This behavior is not changed by this patch, it
> was already present before.
> For example, with the mentioned Octeon III toolchain, output/staging/usr/
> contains:
>     bin      bin32      bin32-fp      bin64-fp,
>     lib      lib32      lib32-fp      lib64-fp
>     libexec  libexec32  libexec32-fp  libexec64-fp
>     sbin     sbin32     sbin32-fp     sbin64-fp
> 
> where bin/lib/libexec/sbin seem to be the 64-bit equivalents of
> bin32/lib32/libexec32/sbin32.
> This is related to the behavior of copy_toolchain_sysroot in
> toolchain/helpers.mk. It already attempts to filter out the unnecessary lib*
> directories, but does not care about any bin/sbin/libexec directories.
> As this poses no known problem and is not impacted by this patch, I make no
> attempt to change it.
> 
>  toolchain/toolchain-external/toolchain-external.mk | 23 ++++++++++++++++++++++
>  1 file changed, 23 insertions(+)
> 
> diff --git a/toolchain/toolchain-external/toolchain-external.mk b/toolchain/toolchain-external/toolchain-external.mk
> index ddefd01..518afd6 100644
> --- a/toolchain/toolchain-external/toolchain-external.mk
> +++ b/toolchain/toolchain-external/toolchain-external.mk
> @@ -517,6 +517,27 @@ endef
>  TOOLCHAIN_EXTERNAL_POST_INSTALL_STAGING_HOOKS += TOOLCHAIN_EXTERNAL_MUSL_LD_LINK
>  endif
>  
> +# Create a symlink from (usr/)$(ARCH_LIB_DIR) to lib.
> +# Note: the skeleton package additionally creates lib32->lib or lib64->lib
> +# (as appropriate)
> +#
> +# $1: destination directory (TARGET_DIR / STAGING_DIR)
> +create_lib_symlinks = \
> +       $(Q)DESTDIR="$(strip $1)" ; \
> +       ARCH_LIB_DIR="$(call toolchain_find_libdir,$(TOOLCHAIN_EXTERNAL_CC) $(TOOLCHAIN_EXTERNAL_CFLAGS))" ; \
> +       if [ ! -e "$${DESTDIR}/$${ARCH_LIB_DIR}" -a ! -e "$${DESTDIR}/usr/$${ARCH_LIB_DIR}" ]; then \
> +               ln -snf lib "$${DESTDIR}/$${ARCH_LIB_DIR}" ; \
> +               ln -snf lib "$${DESTDIR}/usr/$${ARCH_LIB_DIR}" ; \
> +       fi
> +
> +define TOOLCHAIN_EXTERNAL_CREATE_STAGING_LIB_SYMLINK
> +       $(call create_lib_symlinks,$(STAGING_DIR))
> +endef
> +
> +define TOOLCHAIN_EXTERNAL_CREATE_TARGET_LIB_SYMLINK
> +       $(call create_lib_symlinks,$(TARGET_DIR))
> +endef
> +
>  # Integration of the toolchain into Buildroot: find the main sysroot
>  # and the variant-specific sysroot, then copy the needed libraries to
>  # the $(TARGET_DIR) and copy the whole sysroot (libraries and headers)
> @@ -732,6 +753,7 @@ endef
>  TOOLCHAIN_EXTERNAL_BUILD_CMDS = $(TOOLCHAIN_BUILD_WRAPPER)
>  
>  define TOOLCHAIN_EXTERNAL_INSTALL_STAGING_CMDS
> +	$(TOOLCHAIN_EXTERNAL_CREATE_STAGING_LIB_SYMLINK)
>  	$(TOOLCHAIN_EXTERNAL_INSTALL_SYSROOT_LIBS)
>  	$(TOOLCHAIN_EXTERNAL_INSTALL_WRAPPER)
>  	$(TOOLCHAIN_EXTERNAL_INSTALL_GDBINIT)
> @@ -741,6 +763,7 @@ endef
>  # and the target directory, we do everything within the
>  # install-staging step, arbitrarily.
>  define TOOLCHAIN_EXTERNAL_INSTALL_TARGET_CMDS
> +	$(TOOLCHAIN_EXTERNAL_CREATE_TARGET_LIB_SYMLINK)
>  	$(TOOLCHAIN_EXTERNAL_INSTALL_TARGET_LIBS)
>  	$(TOOLCHAIN_EXTERNAL_INSTALL_BFIN_FDPIC)
>  	$(TOOLCHAIN_EXTERNAL_INSTALL_BFIN_FLAT)
>