[Buildroot] [PATCH v9] toolchain: create symlink ARCH_LIB_DIR->lib in addition to lib32/lib64->lib

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

Hi Thomas, All,

Le 22/12/2015 13:35, 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' (likewise for lib64-fp).
> 
> More generally, for external toolchains, the correct symbolic link is
> from (usr/)${ARCH_LIB_DIR} to lib. For internal toolchains, current
> toolchains always use either lib32 or lib64.
> 
> 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
> must be kept.
> 
> Fix the problem as follows:
> - For internal toolchains: no functional change, but move the symlink
>   creation from Makefile to package gcc-initial.
> - For external toolchains: create a symlink creation helper in
>   toolchain/helpers.mk, which first creates lib32->lib or lib64->lib as
>   appropriate, and then creates ARCH_LIB_DIR->lib if that is different from
>   lib32/lib64.

Not so related to your patch though...
I reviewed some patches about x32 and ilp32 toolchains support and it seems that
we need to handle at least two more weird libraries location: libx32 and
libilp32. Each of these series try to define LIB_SYMLINK with their own specific
value (libilp32 and libx32).

See:
x86-64 x32 ABI:
http://patchwork.ozlabs.org/patch/561904/

aarch64 ilp32 ABI:
http://patchwork.ozlabs.org/patch/506803/
http://patchwork.ozlabs.org/patch/506800/
http://patchwork.ozlabs.org/patch/506801/

In your patch, I like create_lib_symlinks helper function which avoid to define
TOOLCHAIN_LIB_SYMLINK with a different value than lib32 and lib64. Instead we
rely on the ARCH_LIB_DIR returned by the arch-sysroot to create additional
symlinks with the correct name.

Obviously, we need to adjust the sed "magic" in toolchain_find_libdir and
toolchain_find_sysroot for libilp32 and libx32 but we can do that in a followup
patch series.

So, I think this patch make it easier to add the support of theses specific
toolchains:

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

Best regards,
Romain

> 
> 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>
> 
> ---
> 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-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 lib32 and lib64, but
> does not care about any bin/sbin/libexec directories, nor about such names
> as lib32-fp.
> As the behavior is not changed by this patch, and as I'm not fully aware
> about which directories are really needed in all cases, I am not touching
> this area.
> ---
>  Makefile                                           |  8 --------
>  package/gcc/gcc-initial/gcc-initial.mk             | 12 +++++++++++
>  package/skeleton/skeleton.mk                       |  4 ----
>  toolchain/helpers.mk                               | 23 ++++++++++++++++++++++
>  toolchain/toolchain-external/toolchain-external.mk | 10 ++++++++++
>  5 files changed, 45 insertions(+), 12 deletions(-)
> 
> diff --git a/Makefile b/Makefile
> index dc657d9..63f4c54 100644
> --- a/Makefile
> +++ b/Makefile
> @@ -448,14 +448,6 @@ world: target-post-image
>  $(BUILD_DIR) $(TARGET_DIR) $(HOST_DIR) $(BINARIES_DIR) $(LEGAL_INFO_DIR) $(REDIST_SOURCES_DIR_TARGET) $(REDIST_SOURCES_DIR_HOST):
>  	@mkdir -p $@
>  
> -# We make a symlink lib32->lib or lib64->lib as appropriate
> -# MIPS64/n32 requires lib32 even though it's a 64-bit arch.
> -ifeq ($(BR2_ARCH_IS_64)$(BR2_MIPS_NABI32),y)
> -LIB_SYMLINK = lib64
> -else
> -LIB_SYMLINK = lib32
> -endif
> -
>  # Populating the staging with the base directories is handled by the skeleton package
>  $(STAGING_DIR):
>  	@mkdir -p $(STAGING_DIR)
> diff --git a/package/gcc/gcc-initial/gcc-initial.mk b/package/gcc/gcc-initial/gcc-initial.mk
> index 1e58d8b..cf441ed 100644
> --- a/package/gcc/gcc-initial/gcc-initial.mk
> +++ b/package/gcc/gcc-initial/gcc-initial.mk
> @@ -64,4 +64,16 @@ HOST_GCC_INITIAL_TOOLCHAIN_WRAPPER_ARGS += $(HOST_GCC_COMMON_TOOLCHAIN_WRAPPER_A
>  HOST_GCC_INITIAL_POST_BUILD_HOOKS += TOOLCHAIN_BUILD_WRAPPER
>  HOST_GCC_INITIAL_POST_INSTALL_HOOKS += HOST_GCC_INSTALL_WRAPPER_AND_SIMPLE_SYMLINKS
>  
> +# The creation of lib32/lib64 symlinks into target and staging directories
> +# needs to be done before the C library is installed. Hooking into the libc
> +# hooks directly is tricky because there are multiple C libraries supported.
> +# Instead, hook into the install step of host-gcc-initial.
> +define HOST_GCC_INITIAL_CREATE_STAGING_TARGET_SYMLINK
> +	$(Q)ln -snf lib $(STAGING_DIR)/$(TOOLCHAIN_LIB_SYMLINK)
> +	$(Q)ln -snf lib $(STAGING_DIR)/usr/$(TOOLCHAIN_LIB_SYMLINK)
> +	$(Q)ln -snf lib $(TARGET_DIR)/$(TOOLCHAIN_LIB_SYMLINK)
> +	$(Q)ln -snf lib $(TARGET_DIR)/usr/$(TOOLCHAIN_LIB_SYMLINK)
> +endef
> +HOST_GCC_INITIAL_POST_INSTALL_HOOKS += HOST_GCC_INITIAL_CREATE_STAGING_TARGET_SYMLINK
> +
>  $(eval $(host-autotools-package))
> diff --git a/package/skeleton/skeleton.mk b/package/skeleton/skeleton.mk
> index 790afaf..b1395b5 100644
> --- a/package/skeleton/skeleton.mk
> +++ b/package/skeleton/skeleton.mk
> @@ -82,8 +82,6 @@ define SKELETON_INSTALL_TARGET_CMDS
>  		--chmod=u=rwX,go=rX --exclude .empty --exclude '*~' \
>  		$(SKELETON_PATH)/ $(TARGET_DIR)/
>  	$(call SKELETON_USR_SYMLINKS_OR_DIRS,$(TARGET_DIR))
> -	ln -snf lib $(TARGET_DIR)/$(LIB_SYMLINK)
> -	ln -snf lib $(TARGET_DIR)/usr/$(LIB_SYMLINK)
>  	$(INSTALL) -m 0644 support/misc/target-dir-warning.txt \
>  		$(TARGET_DIR_WARNING_FILE)
>  endef
> @@ -99,8 +97,6 @@ define SKELETON_INSTALL_STAGING_CMDS
>  	$(INSTALL) -d -m 0755 $(STAGING_DIR)/usr/sbin
>  	$(INSTALL) -d -m 0755 $(STAGING_DIR)/usr/include
>  	$(call SKELETON_USR_SYMLINKS_OR_DIRS,$(STAGING_DIR))
> -	ln -snf lib $(STAGING_DIR)/$(LIB_SYMLINK)
> -	ln -snf lib $(STAGING_DIR)/usr/$(LIB_SYMLINK)
>  endef
>  
>  SKELETON_TARGET_GENERIC_HOSTNAME = $(call qstrip,$(BR2_TARGET_GENERIC_HOSTNAME))
> diff --git a/toolchain/helpers.mk b/toolchain/helpers.mk
> index 1452ec6..f582ce9 100644
> --- a/toolchain/helpers.mk
> +++ b/toolchain/helpers.mk
> @@ -1,5 +1,28 @@
>  # This Makefile fragment declares toolchain related helper functions.
>  
> +# Create the necessary symlink from (usr/)lib32|lib64|lib32-fp|... to lib
> +# In general, for external toolchains, the correct link name is $ARCH_LIB_DIR.
> +# However, there are some broken packages that expect lib32/lib64 anyway.
> +# Therefore, create lib32->lib or lib64->lib (as appropriate) and additionally
> +# $(ARCH_LIB_DIR)->lib.
> +#
> +# MIPS64/n32 requires lib32 even though it's a 64-bit arch.
> +ifeq ($(BR2_ARCH_IS_64)$(BR2_MIPS_NABI32),y)
> +TOOLCHAIN_LIB_SYMLINK = lib64
> +else
> +TOOLCHAIN_LIB_SYMLINK = lib32
> +endif
> +# $1: destination directory (TARGET_DIR / STAGING_DIR)
> +create_lib_symlinks = \
> +	DESTDIR="$(strip $1)" ; \
> +	ARCH_LIB_DIR="$(call toolchain_find_libdir,$(TOOLCHAIN_EXTERNAL_CC) $(TOOLCHAIN_EXTERNAL_CFLAGS))" ; \
> +	ln -snf lib "$${DESTDIR}/$(TOOLCHAIN_LIB_SYMLINK)" ; \
> +	ln -snf lib "$${DESTDIR}/usr/$(TOOLCHAIN_LIB_SYMLINK)" ; \
> +	if [ "$${ARCH_LIB_DIR}" != "lib" -a "$${ARCH_LIB_DIR}" != "$(TOOLCHAIN_LIB_SYMLINK)" ]; then \
> +		ln -snf lib "$${DESTDIR}/$${ARCH_LIB_DIR}" ; \
> +		ln -snf lib "$${DESTDIR}/usr/$${ARCH_LIB_DIR}" ; \
> +	fi
> +
>  # The copy_toolchain_lib_root function copies a toolchain library and
>  # its symbolic links from the sysroot directory to the target
>  # directory. Note that this function is used both by the external
> diff --git a/toolchain/toolchain-external/toolchain-external.mk b/toolchain/toolchain-external/toolchain-external.mk
> index 745b685..e20268e 100644
> --- a/toolchain/toolchain-external/toolchain-external.mk
> +++ b/toolchain/toolchain-external/toolchain-external.mk
> @@ -689,6 +689,14 @@ define TOOLCHAIN_EXTERNAL_INSTALL_SYSROOT_LIBS
>  	$(call copy_toolchain_sysroot,$${SYSROOT_DIR},$${ARCH_SYSROOT_DIR},$${ARCH_SUBDIR},$${ARCH_LIB_DIR},$${SUPPORT_LIB_DIR})
>  endef
>  
> +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
> +
>  # Special installation target used on the Blackfin architecture when
>  # FDPIC is not the primary binary format being used, but the user has
>  # nonetheless requested the installation of the FDPIC libraries to the
> @@ -803,6 +811,7 @@ 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)
> @@ -812,6 +821,7 @@ 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)
>