openbsc: Prepare to allow to have the OpenBSC directory somewhere else

Right now osmo-bts requires access to one OpenBSC header file and
this requires that openbsc and osmo-bts git are in the same directory.
Begin with making the location of the OpenBSC sourcecode configurable.

This approach will allow to build osmo-bts on our Jenkins installation
but now has the risk of more code including the openbsc/*.h header files.

configure.ac

@@ -34,6 +34,11 @@ AC_ARG_ENABLE(sysmocom-bts,
 AC_MSG_RESULT([$enable_sysmocom_bts])
 AM_CONDITIONAL(ENABLE_SYSMOBTS, test "x$enable_sysmocom_bts" = "xyes")
 
+# We share gsm_data.h with OpenBSC and need to be pointed to the source
+# directory of OpenBSC for now.
+openbsc_incdir="\$(abs_top_srcdir)/../openbsc/openbsc/include"
+AC_SUBST([OPENBSC_INCDIR], $openbsc_incdir)
+
 AC_OUTPUT(
     src/Makefile
     src/common/Makefile

include/osmo-bts/gsm_data.h

@@ -73,7 +73,7 @@ enum lchan_ciph_state {
 
 #define bts_role_bts(x)	((struct gsm_bts_role_bts *)(x)->role)
 
-#include "../../openbsc/openbsc/include/openbsc/gsm_data_shared.h"
+#include "openbsc/gsm_data_shared.h"
 
 struct femtol1_hdl;
 

src/common/Makefile.am

@@ -1,4 +1,4 @@
-INCLUDES = $(all_includes) -I$(top_srcdir)/include
+INCLUDES = $(all_includes) -I$(top_srcdir)/include -I$(OPENBSC_INCDIR)
 AM_CFLAGS = -Wall $(LIBOSMOCORE_CFLAGS) $(LIBOSMOTRAU_CFLAGS)
 LDADD = $(LIBOSMOCORE_LIBS) $(LIBOSMOTRAU_LIBS)
 

src/osmo-bts-sysmo/Makefile.am

@@ -1,4 +1,4 @@
-INCLUDES = $(all_includes) -I$(top_srcdir)/include
+INCLUDES = $(all_includes) -I$(top_srcdir)/include -I$(OPENBSC_INCDIR)
 AM_CFLAGS = -Wall $(LIBOSMOCORE_CFLAGS) $(LIBOSMOGSM_CFLAGS) $(LIBOSMOVTY_CFLAGS) $(LIBOSMOTRAU_CFLAGS)
 LDADD = $(LIBOSMOCORE_LIBS) $(LIBOSMOGSM_LIBS) $(LIBOSMOVTY_LIBS) $(LIBOSMOTRAU_LIBS) -lortp
 

tests/paging/Makefile.am

@@ -1,4 +1,4 @@
-INCLUDES = $(all_includes) -I$(top_srcdir)/include
+INCLUDES = $(all_includes) -I$(top_srcdir)/include -I$(OPENBSC_INCDIR)
 AM_CFLAGS = -Wall $(LIBOSMOCORE_CFLAGS) $(LIBOSMOGSM_CFLAGS) $(LIBOSMOVTY_CFLAGS) $(LIBOSMOTRAU_CFLAGS)
 LDADD = $(LIBOSMOCORE_LIBS) $(LIBOSMOGSM_LIBS) $(LIBOSMOVTY_LIBS) $(LIBOSMOTRAU_LIBS) -lortp
 noinst_PROGRAMS = paging_test