Add JSON API for Asterisk.

This provides a JSON API by pulling in and wrapping the Jansson JSON
library[1]. The Asterisk API basically mirrors the Jansson
functionality, with a few minor tweaks.

 * Some names have been asteriskified to protect the innocent.
 * Jansson provides both reference-stealing and reference-borrowing
   versions of several API's. The Asterisk API is exclusively
   reference-stealing for operations that put elements into arrays and
   objects.
 * No support for doubles, since we usually don't need that.
 * Coming along for the ride is the ast_test_validate macro, which made
   the unit tests much easier to write.

 [1]: http://www.digip.org/jansson/

(issue ASTERISK-20887)
(closes issue ASTERISK-20888)
Review: https://reviewboard.asterisk.org/r/2264/


git-svn-id: https://origsvn.digium.com/svn/asterisk/trunk@378915 65c4cc65-6c06-0410-ace0-fbb531ad65f3

configure

@@ -1,5 +1,5 @@
 #! /bin/sh
-# From configure.ac Revision: 377977 .
+# From configure.ac Revision: 377981 .
 # Guess values for system-dependent variables and create Makefiles.
 # Generated by GNU Autoconf 2.69 for asterisk trunk.
 #
@@ -974,6 +974,10 @@ PBX_KQUEUE
 KQUEUE_DIR
 KQUEUE_INCLUDE
 KQUEUE_LIB
+PBX_JANSSON
+JANSSON_DIR
+JANSSON_INCLUDE
+JANSSON_LIB
 PBX_JACK
 JACK_DIR
 JACK_INCLUDE
@@ -1245,6 +1249,7 @@ with_inotify
 with_iodbc
 with_isdnnet
 with_jack
+with_jansson
 with_kqueue
 with_ldap
 with_libcurl
@@ -1972,6 +1977,7 @@ Optional Packages:
   --with-iodbc=PATH       use iODBC files in PATH
   --with-isdnnet=PATH     use ISDN4Linux files in PATH
   --with-jack=PATH        use Jack Audio Connection Kit files in PATH
+  --with-jansson=PATH     use Jansson JSON library files in PATH
   --with-kqueue=PATH      use kqueue support files in PATH
   --with-ldap=PATH        use OpenLDAP files in PATH
   --with-libcurl=DIR      look for the curl library in DIR
@@ -8911,6 +8917,38 @@ fi
 
 
 
+    JANSSON_DESCRIP="Jansson JSON library"
+    JANSSON_OPTION="jansson"
+    PBX_JANSSON=0
+
+# Check whether --with-jansson was given.
+if test "${with_jansson+set}" = set; then :
+  withval=$with_jansson;
+	case ${withval} in
+	n|no)
+	USE_JANSSON=no
+	# -1 is a magic value used by menuselect to know that the package
+	# was disabled, other than 'not found'
+	PBX_JANSSON=-1
+	;;
+	y|ye|yes)
+	ac_mandatory_list="${ac_mandatory_list} JANSSON"
+	;;
+	*)
+	JANSSON_DIR="${withval}"
+	ac_mandatory_list="${ac_mandatory_list} JANSSON"
+	;;
+	esac
+
+fi
+
+
+
+
+
+
+
+
     KQUEUE_DESCRIP="kqueue support"
     KQUEUE_OPTION="kqueue"
     PBX_KQUEUE=0
@@ -19865,6 +19903,111 @@ fi
 
 
 
+
+if test "x${PBX_JANSSON}" != "x1" -a "${USE_JANSSON}" != "no"; then
+   pbxlibdir=""
+   # if --with-JANSSON=DIR has been specified, use it.
+   if test "x${JANSSON_DIR}" != "x"; then
+      if test -d ${JANSSON_DIR}/lib; then
+      	 pbxlibdir="-L${JANSSON_DIR}/lib"
+      else
+      	 pbxlibdir="-L${JANSSON_DIR}"
+      fi
+   fi
+   pbxfuncname="json_dumps"
+   if test "x${pbxfuncname}" = "x" ; then   # empty lib, assume only headers
+      AST_JANSSON_FOUND=yes
+   else
+      ast_ext_lib_check_save_CFLAGS="${CFLAGS}"
+      CFLAGS="${CFLAGS} "
+      as_ac_Lib=`$as_echo "ac_cv_lib_jansson_${pbxfuncname}" | $as_tr_sh`
+{ $as_echo "$as_me:${as_lineno-$LINENO}: checking for ${pbxfuncname} in -ljansson" >&5
+$as_echo_n "checking for ${pbxfuncname} in -ljansson... " >&6; }
+if eval \${$as_ac_Lib+:} false; then :
+  $as_echo_n "(cached) " >&6
+else
+  ac_check_lib_save_LIBS=$LIBS
+LIBS="-ljansson ${pbxlibdir}  $LIBS"
+cat confdefs.h - <<_ACEOF >conftest.$ac_ext
+/* end confdefs.h.  */
+
+/* Override any GCC internal prototype to avoid an error.
+   Use char because int might match the return type of a GCC
+   builtin and then its argument prototype would still apply.  */
+#ifdef __cplusplus
+extern "C"
+#endif
+char ${pbxfuncname} ();
+int
+main ()
+{
+return ${pbxfuncname} ();
+  ;
+  return 0;
+}
+_ACEOF
+if ac_fn_c_try_link "$LINENO"; then :
+  eval "$as_ac_Lib=yes"
+else
+  eval "$as_ac_Lib=no"
+fi
+rm -f core conftest.err conftest.$ac_objext \
+    conftest$ac_exeext conftest.$ac_ext
+LIBS=$ac_check_lib_save_LIBS
+fi
+eval ac_res=\$$as_ac_Lib
+	       { $as_echo "$as_me:${as_lineno-$LINENO}: result: $ac_res" >&5
+$as_echo "$ac_res" >&6; }
+if eval test \"x\$"$as_ac_Lib"\" = x"yes"; then :
+  AST_JANSSON_FOUND=yes
+else
+  AST_JANSSON_FOUND=no
+fi
+
+      CFLAGS="${ast_ext_lib_check_save_CFLAGS}"
+   fi
+
+   # now check for the header.
+   if test "${AST_JANSSON_FOUND}" = "yes"; then
+      JANSSON_LIB="${pbxlibdir} -ljansson "
+      # if --with-JANSSON=DIR has been specified, use it.
+      if test "x${JANSSON_DIR}" != "x"; then
+         JANSSON_INCLUDE="-I${JANSSON_DIR}/include"
+      fi
+      JANSSON_INCLUDE="${JANSSON_INCLUDE} "
+      if test "xjansson.h" = "x" ; then	# no header, assume found
+         JANSSON_HEADER_FOUND="1"
+      else				# check for the header
+         ast_ext_lib_check_saved_CPPFLAGS="${CPPFLAGS}"
+         CPPFLAGS="${CPPFLAGS} ${JANSSON_INCLUDE}"
+         ac_fn_c_check_header_mongrel "$LINENO" "jansson.h" "ac_cv_header_jansson_h" "$ac_includes_default"
+if test "x$ac_cv_header_jansson_h" = xyes; then :
+  JANSSON_HEADER_FOUND=1
+else
+  JANSSON_HEADER_FOUND=0
+fi
+
+
+         CPPFLAGS="${ast_ext_lib_check_saved_CPPFLAGS}"
+      fi
+      if test "x${JANSSON_HEADER_FOUND}" = "x0" ; then
+         JANSSON_LIB=""
+         JANSSON_INCLUDE=""
+      else
+         if test "x${pbxfuncname}" = "x" ; then		# only checking headers -> no library
+            JANSSON_LIB=""
+         fi
+         PBX_JANSSON=1
+         cat >>confdefs.h <<_ACEOF
+#define HAVE_JANSSON 1
+_ACEOF
+
+      fi
+   fi
+fi
+
+
+
 # BSD (and OS X) equivalent of inotify
 
 if test "x${PBX_KQUEUE}" != "x1" -a "${USE_KQUEUE}" != "no"; then