From a0cdfcf936bcccd15d08a22c9cf38013b6859ad2 Mon Sep 17 00:00:00 2001
From: David Marchand <david.marchand@6wind.com>
Date: Fri, 22 Nov 2013 11:24:55 +0100
Subject: [PATCH] pcap: use pcap-config to guess compilation flags

Use pcap-config to populate CFLAGS and LDFLAGS.
LIBPCAP_CFLAGS and LIBPCAP_LDFLAGS can be used to override this (useful when
cross-compiling).

Signed-off-by: David Marchand <david.marchand@6wind.com>
Acked-by: Thomas Monjalon <thomas.monjalon@6wind.com>
---
 app/test-pmd/Makefile         | 4 ----
 doc/build-sdk-quick.txt       | 2 ++
 mk/rte.app.mk                 | 5 ++++-
 mk/rte.sdkbuild.mk            | 8 ++++++++
 mk/target/generic/rte.vars.mk | 2 +-
 5 files changed, 15 insertions(+), 6 deletions(-)

diff --git a/app/test-pmd/Makefile b/app/test-pmd/Makefile
index 4f80442cd4..761d1daefa 100644
--- a/app/test-pmd/Makefile
+++ b/app/test-pmd/Makefile
@@ -39,10 +39,6 @@ APP = testpmd
 CFLAGS += -O3
 CFLAGS += $(WERROR_FLAGS)
 
-ifeq ($(CONFIG_RTE_LIBRTE_PMD_PCAP),y)
-LDFLAGS += -lpcap
-endif
-
 #
 # all source are stored in SRCS-y
 #
diff --git a/doc/build-sdk-quick.txt b/doc/build-sdk-quick.txt
index 8989a32a60..bf7c350fcc 100644
--- a/doc/build-sdk-quick.txt
+++ b/doc/build-sdk-quick.txt
@@ -11,6 +11,8 @@ Build variables
 	EXTRA_CPPFLAGS   preprocessor options
 	EXTRA_CFLAGS     compiler options
 	EXTRA_LDFLAGS    linker options
+	LIBPCAP_CFLAGS   libpcap compiler options
+	LIBPCAP_LDFLAGS  libpcap linker options
 	RTE_KERNELDIR    linux headers path
 	CROSS     toolchain prefix
 	V         verbose
diff --git a/mk/rte.app.mk b/mk/rte.app.mk
index ec8e24eebb..d90a0b0eaf 100644
--- a/mk/rte.app.mk
+++ b/mk/rte.app.mk
@@ -170,7 +170,10 @@ LDLIBS += -lrte_cmdline
 endif
 
 ifeq ($(CONFIG_RTE_LIBRTE_PMD_PCAP),y)
-LDLIBS += -lrte_pmd_pcap -lpcap
+LDLIBS += -lrte_pmd_pcap
+LIBPCAP_LDFLAGS ?= $(shell pcap-config --libs)
+$(if $(LIBPCAP_LDFLAGS),,$(error LIBPCAP_LDFLAGS is undefined))
+LDLIBS += $(LIBPCAP_LDFLAGS)
 endif
 
 LDLIBS += $(EXECENV_LDLIBS)
diff --git a/mk/rte.sdkbuild.mk b/mk/rte.sdkbuild.mk
index 2975ee413b..0b6a7df8b9 100644
--- a/mk/rte.sdkbuild.mk
+++ b/mk/rte.sdkbuild.mk
@@ -40,6 +40,14 @@ else
   include $(RTE_SDK)/mk/rte.vars.mk
 endif
 
+ifeq ($(CONFIG_RTE_LIBRTE_PMD_PCAP),y)
+LIBPCAP_CFLAGS ?= $(shell pcap-config --cflags)
+$(if $(LIBPCAP_CFLAGS),,$(error LIBPCAP_CFLAGS is undefined))
+EXTERNAL_LIB_CFLAGS += $(LIBPCAP_CFLAGS)
+endif
+
+export EXTERNAL_LIB_CFLAGS
+
 #
 # include .depdirs and define rules to order priorities between build
 # of directories.
diff --git a/mk/target/generic/rte.vars.mk b/mk/target/generic/rte.vars.mk
index 796cca7da2..a163272949 100644
--- a/mk/target/generic/rte.vars.mk
+++ b/mk/target/generic/rte.vars.mk
@@ -108,7 +108,7 @@ include $(RTE_SDK)/mk/rte.cpuflags.mk
 
 # merge all CFLAGS
 CFLAGS := $(CPU_CFLAGS) $(EXECENV_CFLAGS) $(TOOLCHAIN_CFLAGS) $(MACHINE_CFLAGS)
-CFLAGS += $(TARGET_CFLAGS)
+CFLAGS += $(TARGET_CFLAGS) $(EXTERNAL_LIB_CFLAGS)
 
 # merge all LDFLAGS
 LDFLAGS := $(CPU_LDFLAGS) $(EXECENV_LDFLAGS) $(TOOLCHAIN_LDFLAGS) $(MACHINE_LDFLAGS)