[dpdk-dev] [PATCH] mk: generate internal library dependencies from DEPDIRS-y automatically

[Panu Matilainen <pmatilai@redhat.com>]

Up to now dependencies between DPDK internal libraries have been
untracked at shared library level, requiring applications to know
about library internal dependencies and often consequently overlinking.

Since the dependencies are already recorded for build ordering in the
makefiles, we can use that information to generate LDLIBS entries for
internal libraries automatically.

Also revert commit 8180554d82b3 ("vhost: fix linkage of driver with
library") which is made redundant by this change.

Signed-off-by: Panu Matilainen <pmatilai@redhat.com>
---
 drivers/net/vhost/Makefile | 1 -
 mk/rte.lib.mk              | 7 +++++++
 2 files changed, 7 insertions(+), 1 deletion(-)

diff --git a/drivers/net/vhost/Makefile b/drivers/net/vhost/Makefile
index 30b91a0..f49a69b 100644
--- a/drivers/net/vhost/Makefile
+++ b/drivers/net/vhost/Makefile
@@ -38,7 +38,6 @@ LIB = librte_pmd_vhost.a
 
 CFLAGS += -O3
 CFLAGS += $(WERROR_FLAGS)
-LDLIBS += -lrte_vhost
 
 EXPORT_MAP := rte_pmd_vhost_version.map
 
diff --git a/mk/rte.lib.mk b/mk/rte.lib.mk
index b420280..1ff403f 100644
--- a/mk/rte.lib.mk
+++ b/mk/rte.lib.mk
@@ -77,6 +77,13 @@ else
 _CPU_LDFLAGS := $(CPU_LDFLAGS)
 endif
 
+# Translate DEPDIRS-y into LDLIBS
+# Ignore (sub)directory dependencies which do not provide an actual library
+_IGNORE_DIRS = lib/librte_eal/% lib/librte_net lib/librte_compat
+_DEPDIRS = $(filter-out $(_IGNORE_DIRS),$(DEPDIRS-y))
+_LDDIRS = $(subst librte_ether,libethdev,$(_DEPDIRS))
+LDLIBS += $(subst lib/lib,-l,$(_LDDIRS))
+
 O_TO_A = $(AR) crDs $(LIB) $(OBJS-y)
 O_TO_A_STR = $(subst ','\'',$(O_TO_A)) #'# fix syntax highlight
 O_TO_A_DISP = $(if $(V),"$(O_TO_A_STR)","  AR $(@)")
-- 
2.5.5