[dpdk-stable] patch 'mk: fix lib filtering when linking app' has been queued to LTS release 16.11.2

[Yuanhan Liu <yuanhan.liu@linux.intel.com>]

Hi,

FYI, your patch has been queued to LTS release 16.11.2

Note it hasn't been pushed to http://dpdk.org/browse/dpdk-stable
yet. It will be pushed if I get no objections before 04/11/17.
So please shout if anyone has objections.

Thanks.

	--yliu

---
>From 5d23520c8e6388b684b0c82fe636ee4148af7f6e Mon Sep 17 00:00:00 2001
From: Olivier Matz <olivier.matz@6wind.com>
Date: Thu, 6 Apr 2017 16:14:55 +0200
Subject: [PATCH] mk: fix lib filtering when linking app

[ upstream commit ab338eb44ebb79840dab1de2742c07070ae3bf0e ]

I get the following error when linking the test application:
  build/lib/librte_pmd_thunderx_nicvf.a(nicvf_hw.o):
  In function `nicvf_qsize_regbit':
  drivers/net/thunderx/base/nicvf_hw.c:451: undefined reference to `log2'
  build/lib/librte_pmd_thunderx_nicvf.a(nicvf_hw.o):
  In function `nicvf_rss_reta_update':
  drivers/net/thunderx/base/nicvf_hw.c:804: undefined reference to `log2'
  build/lib/librte_pmd_thunderx_nicvf.a(nicvf_hw.o):
  In function `nicvf_rss_reta_query':
  drivers/net/thunderx/base/nicvf_hw.c:825: undefined reference to `log2'

While I don't know why it does not happen for a default build, the error
can be explained. The link command line is:

   gcc -o test ... *.o ... -Wl,-lm ... -Wl,-lrte_pmd_thunderx_nicvf ...

rte_pmd_thunderx_nicvf needs the math library, and it should be
added after. This is not the case because the test application also
adds the math library.

The makefile already filters the libraries, but it keeps the first
occurrence of the lib. Instead, the last one should be kept.

Fixes: edf4d331dcdb ("mk: eliminate duplicates from libraries list")

Signed-off-by: Olivier Matz <olivier.matz@6wind.com>
Acked-by: Thomas Monjalon <thomas.monjalon@6wind.com>
---
 mk/rte.app.mk | 19 +++++++++++++++----
 1 file changed, 15 insertions(+), 4 deletions(-)

diff --git a/mk/rte.app.mk b/mk/rte.app.mk
index f75f0e2..725e01d 100644
--- a/mk/rte.app.mk
+++ b/mk/rte.app.mk
@@ -168,10 +168,21 @@ _LDLIBS-y += $(EXECENV_LDLIBS)
 
 LDLIBS += $(_LDLIBS-y) $(CPU_LDLIBS) $(EXTRA_LDLIBS)
 
-# Eliminate duplicates without sorting
-LDLIBS := $(shell echo $(LDLIBS) | \
-	awk '{for (i = 1; i <= NF; i++) { \
-		if ($$i !~ /^-l.*/ || !seen[$$i]++) print $$i }}')
+# all the words except the first one
+allbutfirst = $(wordlist 2,$(words $(1)),$(1))
+
+# Eliminate duplicates without sorting, only keep the last occurrence
+filter-libs = \
+	$(if $(1),$(strip\
+		$(if \
+			$(and \
+				$(filter $(firstword $(1)),$(call allbutfirst,$(1))),\
+				$(filter -l%,$(firstword $(1)))),\
+			,\
+			$(firstword $(1))) \
+		$(call filter-libs,$(call allbutfirst,$(1)))))
+
+LDLIBS := $(call filter-libs,$(LDLIBS))
 
 ifeq ($(RTE_DEVEL_BUILD)$(CONFIG_RTE_BUILD_SHARED_LIB),yy)
 LDFLAGS += -rpath=$(RTE_SDK_BIN)/lib
-- 
1.9.0