5708: allow gnunet-config to output build config informations

With this commit, `gnunet-config' is now able to print some informations about
how GNUnet was built through some additional flags (here `--cflags', `--libs'
and `--prefix'.)

These flags allow `gnunet-config' to behave like other `*-config' tools
provided by other applications/libraries, which are used by third-party
applications, especially when the tool is provided by a library, to properly
compile using the flags recommended by the library/application.

In terms of GNUnet, any client or service connecting to any GNUnet service can
now be built using some variation of the following:

cc $(gnunet-config --cflags) -o my-client client.c $(gnunet-config --libs)

1 files changed, 5 insertions, 0 deletions

diff --git a/src/util/Makefile.am b/src/util/Makefile.am
index e720112be..ab66756b4 100644
--- a/src/util/Makefile.am
+++ b/src/util/Makefile.am
@@ -227,6 +227,11 @@ gnunet_config_SOURCES = \
 gnunet_config_LDADD = \
   libgnunetutil.la \
   $(GN_LIBINTL)
+gnunet_config_CPPFLAGS = \
+ -DINCLUDEDIR=\"$(includedir)\" \
+ -DLIBDIR=\"$(libdir)\" \
+ -DPREFIX=\"$(prefix)\" \
+ $(AM_CPPFLAGS)
 
 gnunet_uri_SOURCES = \
  gnunet-uri.c