+# --with-libgnutls {{{
+with_libgnutls_cflags="$GNUTLS_CFLAGS"
+with_libgnutls_libs="$GNUTLS_LIBS"
+AC_ARG_WITH(libgnutls, [AS_HELP_STRING([--with-libgnutls@<:@=PREFIX@:>@], [Path to GnuTLS.])],
+[
+ if test "x$withval" = "xno"
+ then
+ with_libgnutls="no"
+ else if test "x$withval" = "xyes"
+ then
+ with_libgnutls="use_pkgconfig"
+ else if test -d "$with_libgnutls/lib"
+ then
+ AC_MSG_NOTICE([Not checking for libgnutls: Manually configured])
+ with_libgnutls_cflags="-I$withval/include"
+ with_libgnutls_libs="-L$withval/lib -lgnutls"
+ with_libgnutls="yes"
+ fi; fi; fi
+],
+[with_libgnutls="use_pkgconfig"])
+
+# configure using pkg-config
+if test "x$with_libgnutls" = "xuse_pkgconfig"
+then
+ if test "x$PKG_CONFIG" = "x"
+ then
+ with_libgnutls="no (Don't have pkg-config)"
+ fi
+fi
+if test "x$with_libgnutls" = "xuse_pkgconfig"
+then
+ AC_MSG_NOTICE([Checking for gnutls using $PKG_CONFIG])
+ $PKG_CONFIG --exists 'gnutls' 2>/dev/null
+ if test $? -ne 0
+ then
+ with_libgnutls="no (pkg-config doesn't know gnutls)"
+ fi
+fi
+if test "x$with_libgnutls" = "xuse_pkgconfig"
+then
+ with_libgnutls_cflags="`$PKG_CONFIG --cflags 'gnutls'`"
+ if test $? -ne 0
+ then
+ with_libgnutls="no ($PKG_CONFIG failed)"
+ fi
+ with_libgnutls_libs="`$PKG_CONFIG --libs 'gnutls'`"
+ if test $? -ne 0
+ then
+ with_libgnutls="no ($PKG_CONFIG failed)"
+ fi
+fi
+if test "x$with_libgnutls" = "xuse_pkgconfig"
+then
+ with_libgnutls="yes"
+fi
+
+SAVE_CPPFLAGS="$CPPFLAGS"
+CPPFLAGS="$CPPFLAGS $with_libgnutls_cflags"
+
+# with_libgnutls_cflags and with_libgnutls_libs are set up now, let's do
+# the actual checks.
+if test "x$with_libgnutls" = "xyes"
+then
+ AC_CHECK_HEADERS(gnutls/gnutls.h, [], [with_libgnutls="no (gnutls/gnutls.h not found)"])
+fi
+if test "x$with_libgnutls" = "xyes"
+then
+ AC_CHECK_HEADERS(gnutls/dtls.h gnutls/openpgp.h)
+fi
+if test "x$with_libgnutls" = "xyes"
+then
+ AC_CHECK_LIB(gnutls, gnutls_global_init,
+ [with_libgnutls="yes"],
+ [with_libgnutls="no (symbol gnutls_global_init not found)"],
+ [$with_libgnutls_libs])
+fi
+if test "x$with_libgnutls" = "xyes"
+then
+ BUILD_WITH_LIBGNUTLS_CFLAGS="$with_libgnutls_cflags"
+ BUILD_WITH_LIBGNUTLS_LIBS="$with_libgnutls_libs"
+ AC_SUBST(BUILD_WITH_LIBGNUTLS_CFLAGS)
+ AC_SUBST(BUILD_WITH_LIBGNUTLS_LIBS)
+fi
+
+CPPFLAGS="$SAVE_CPPFLAGS"
+# }}}
+