[Buildroot] [PATCH v7 04/18] core: staging symlink uses a relative path when possible

[Samuel Martin <s.martin49@gmail.com>]

This change turns the staging/ symlink to a relative one when
$(STAGING_DIR) points to some location in the Buildroot's output
directory (i.e.: in $(BASE_DIR)/).

In any other case, the symlink target remains the absolute path
to the sysroot location.

This slight change is a step forward toward a relocatable SDK.

Signed-off-by: Samuel Martin <s.martin49@gmail.com>

---
changes v6->v7:
- improve commit log (ThomasP)

changes v5->v6:
- no changes

changes v4->v5:
- add support when BR2_HOST_DIR is set somewhere out of BASE_DIR

changes v3->v4:
- no change

changes v2->v3:
- no change
---
 Makefile | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/Makefile b/Makefile
index 52a92f6..f1de4ed 100644
--- a/Makefile
+++ b/Makefile
@@ -518,7 +518,11 @@ $(BUILD_DIR) $(TARGET_DIR) $(HOST_DIR) $(BINARIES_DIR) $(LEGAL_INFO_DIR) $(REDIS
 # Populating the staging with the base directories is handled by the skeleton package
 $(STAGING_DIR):
 	@mkdir -p $(STAGING_DIR)
+ifeq ($(BASE_DIR)/host/$(STAGING_SUBDIR),$(STAGING_DIR))
+	@ln -snf host/$(STAGING_SUBDIR) $(BASE_DIR)/staging
+else
 	@ln -snf $(STAGING_DIR) $(BASE_DIR)/staging
+endif
 
 RSYNC_VCS_EXCLUSIONS = \
 	--exclude .svn --exclude .git --exclude .hg --exclude .bzr \
-- 
2.7.2