[RFCv2,3/7] Makefile, skeleton: move the host skeleton logic to host-skeleton package

As part of the per-package SDK work, we want to avoid having logic
that installs files to the global HOST_DIR, and instead do it inside
packages. One thing that gets installed to the global HOST_DIR is the
minimal "skeleton" that we create in host:

 - the "usr" symbolic link for backward compatibility

 - the "lib" directory, and its lib64 or lib32 symbolic links

This commit moves this logic to a new host-skeleton package, and makes
all packages (except itself) depend on it. We also make sure that this
host-skeleton package doesn't depend on host-patchelf, because
host-patchelf depends on host-skeleton.

Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>
---
Changes since v1:
 - New patch
---
 Makefile                     | 13 +------------
 package/pkg-generic.mk       |  4 ++++
 package/skeleton/skeleton.mk | 12 ++++++++++++
 3 files changed, 17 insertions(+), 12 deletions(-)

Hi Thomas,

On Fri, Nov 24, 2017 at 05:46:06PM +0100, Thomas Petazzoni wrote:
> As part of the per-package SDK work, we want to avoid having logic
> that installs files to the global HOST_DIR, and instead do it inside
> packages. One thing that gets installed to the global HOST_DIR is the
> minimal "skeleton" that we create in host:
> 
>  - the "usr" symbolic link for backward compatibility
> 
>  - the "lib" directory, and its lib64 or lib32 symbolic links
> 
> This commit moves this logic to a new host-skeleton package, and makes
> all packages (except itself) depend on it. We also make sure that this
> host-skeleton package doesn't depend on host-patchelf, because
> host-patchelf depends on host-skeleton.

AFAICS, host-patchelf becomes a dependency of all packages only in patch #6. 
Maybe this last sentence should move there.

baruch

> Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>
> ---
> Changes since v1:
>  - New patch
> ---
>  Makefile                     | 13 +------------
>  package/pkg-generic.mk       |  4 ++++
>  package/skeleton/skeleton.mk | 12 ++++++++++++
>  3 files changed, 17 insertions(+), 12 deletions(-)
> 
> diff --git a/Makefile b/Makefile
> index 55409b99af..193864a0df 100644
> --- a/Makefile
> +++ b/Makefile
> @@ -544,7 +544,7 @@ endif
>  
>  .PHONY: dirs
>  dirs: $(BUILD_DIR) $(STAGING_DIR) $(TARGET_DIR) \
> -	$(HOST_DIR) $(HOST_DIR)/usr $(HOST_DIR)/lib $(BINARIES_DIR)
> +	$(HOST_DIR) $(BINARIES_DIR)
>  
>  $(BUILD_DIR)/buildroot-config/auto.conf: $(BR2_CONFIG)
>  	$(MAKE1) $(EXTRAMAKEARGS) HOSTCC="$(HOSTCC_NOCCACHE)" HOSTCXX="$(HOSTCXX_NOCCACHE)" silentoldconfig
> @@ -563,17 +563,6 @@ sdk: world
>  	$(INSTALL) -m 755 $(TOPDIR)/support/misc/relocate-sdk.sh $(HOST_DIR)/relocate-sdk.sh
>  	echo $(HOST_DIR) > $(HOST_DIR)/share/buildroot/sdk-location
>  
> -# Compatibility symlink in case a post-build script still uses $(HOST_DIR)/usr
> -$(HOST_DIR)/usr: $(HOST_DIR)
> -	@ln -snf . $@
> -
> -$(HOST_DIR)/lib: $(HOST_DIR)
> -	@mkdir -p $@
> -	@case $(HOSTARCH) in \
> -		(*64) ln -snf lib $(@D)/lib64;; \
> -		(*)   ln -snf lib $(@D)/lib32;; \
> -	esac
> -
>  # Populating the staging with the base directories is handled by the skeleton package
>  $(STAGING_DIR):
>  	@mkdir -p $(STAGING_DIR)
> diff --git a/package/pkg-generic.mk b/package/pkg-generic.mk
> index 0e28675fbe..574a5861d0 100644
> --- a/package/pkg-generic.mk
> +++ b/package/pkg-generic.mk
> @@ -564,6 +564,10 @@ $(2)_DEPENDENCIES += toolchain
>  endif
>  endif
>  
> +ifneq ($(1),host-skeleton)
> +$(2)_DEPENDENCIES += host-skeleton
> +endif
> +
>  # Eliminate duplicates in dependencies
>  $(2)_FINAL_DEPENDENCIES = $$(sort $$($(2)_DEPENDENCIES))
>  $(2)_FINAL_PATCH_DEPENDENCIES = $$(sort $$($(2)_PATCH_DEPENDENCIES))
> diff --git a/package/skeleton/skeleton.mk b/package/skeleton/skeleton.mk
> index d380f41649..a32bacd0b3 100644
> --- a/package/skeleton/skeleton.mk
> +++ b/package/skeleton/skeleton.mk
> @@ -11,4 +11,16 @@
>  SKELETON_ADD_TOOLCHAIN_DEPENDENCY = NO
>  SKELETON_ADD_SKELETON_DEPENDENCY = NO
>  
> +# We create a compatibility symlink in case a post-build script still
> +# uses $(HOST_DIR)/usr
> +define HOST_SKELETON_INSTALL_CMDS
> +	@ln -snf . $(HOST_DIR)/usr
> +	@mkdir -p $(HOST_DIR)/lib
> +	@case $(HOSTARCH) in \
> +		(*64) ln -snf lib $(HOST_DIR)/lib64;; \
> +		(*)   ln -snf lib $(HOST_DIR)/lib32;; \
> +	esac
> +endef
> +
>  $(eval $(virtual-package))
> +$(eval $(host-generic-package))

Hello,

On Sat, 25 Nov 2017 21:46:50 +0200, Baruch Siach wrote:
> Hi Thomas,
> 
> On Fri, Nov 24, 2017 at 05:46:06PM +0100, Thomas Petazzoni wrote:
> > As part of the per-package SDK work, we want to avoid having logic
> > that installs files to the global HOST_DIR, and instead do it inside
> > packages. One thing that gets installed to the global HOST_DIR is the
> > minimal "skeleton" that we create in host:
> > 
> >  - the "usr" symbolic link for backward compatibility
> > 
> >  - the "lib" directory, and its lib64 or lib32 symbolic links
> > 
> > This commit moves this logic to a new host-skeleton package, and makes
> > all packages (except itself) depend on it. We also make sure that this
> > host-skeleton package doesn't depend on host-patchelf, because
> > host-patchelf depends on host-skeleton.  
> 
> AFAICS, host-patchelf becomes a dependency of all packages only in patch #6. 
> Maybe this last sentence should move there.

True. This patch originally was *after* the change of the RPATH
strategy, and I decided to move it earlier in t he patch series, hoping
that it could be merged earlier than the bigger/more controversial
changes.

I'll fix that in v3.

Thanks for the review!

Thomas