make: adding --with-sai arg to select which SAI to compile with (#6)

configure.ac

@@ -20,6 +20,16 @@ AC_ARG_ENABLE(debug,
 esac],[debug=false])
 AM_CONDITIONAL(DEBUG, test x$debug = xtrue)
 
+AC_ARG_WITH(sai,
+[  --with-sai        Compiling against specific SAI],
+[case "${withval}" in
+	bcm)  sai=bcm ;;
+	mlnx) sai=mlnx ;;
+	*) AC_MSG_ERROR(bad value ${withval} for --with-sai) ;;
+esac])
+AM_CONDITIONAL(SAIBCM,  test x$sai = xbcm)
+AM_CONDITIONAL(SAIMLNX, test x$sai = xmlnx)
+
 CFLAGS_COMMON="-std=c++11 -Wall -fPIC -Wno-write-strings"
 AC_SUBST(CFLAGS_COMMON)
 

syncd/Makefile.am

@@ -9,6 +9,14 @@ else
 DBGFLAGS = -g
 endif
 
+if SAIBCM
+SAIFLAGS = -DBRCMSAI
+endif
+
+if SAIMLNX
+SAIFLAGS = -DMLNXSAI
+endif
+
 syncd_SOURCES = syncd.cpp \
 		syncd_init.cpp \
 		syncd_notifications.cpp \
@@ -17,6 +25,6 @@ syncd_SOURCES = syncd.cpp \
 
 syncd_CPPFLAGS = $(DBGFLAGS) $(AM_CPPFLAGS) $(CFLAGS_COMMON) \
 				 -I$(top_srcdir)/lib/inc \
-				 -I/usr/include/sai
+				 -I/usr/include/sai $(SAIFLAGS)
 syncd_LDADD = -lhiredis -lswsscommon -lsai -lpthread
 

syncd/syncd.cpp

@@ -582,8 +582,10 @@ int main(int argc, char **argv)
         exit(EXIT_FAILURE);
     }
 
+#ifdef BRCMSAI
     std::thread bcm_diag_shell_thread = std::thread(sai_diag_shell);
     bcm_diag_shell_thread.detach();
+#endif /* BRCMSAI */
 #else
     sai_switch_api->initialize_switch(
             0,  // profile id