[PATCH RFC V2 03/10] libxl_internal: make JSON_* types bit-field

[Wei Liu <wei.liu2@citrix.com>]

Libxl can generate number as type JSON_INTEGER, JSON_DOUBLE or
JSON_NUMBER, string as type JSON_STRING or JSON_NULL (if string is
null).

So make JSON_* type a bit-field and use it in libxl__json_map_get. This is
useful when parsing a libxl__json_object to libxl_FOO struct. We can
enforce type checking on libxl__json_object in an easy way.

Signed-off-by: Wei Liu <wei.liu2@citrix.com>
---
 tools/libxl/libxl_internal.h |   18 +++++++++---------
 tools/libxl/libxl_json.c     |    2 +-
 2 files changed, 10 insertions(+), 10 deletions(-)

diff --git a/tools/libxl/libxl_internal.h b/tools/libxl/libxl_internal.h
index 9205c49..a5b2669 100644
--- a/tools/libxl/libxl_internal.h
+++ b/tools/libxl/libxl_internal.h
@@ -1622,16 +1622,16 @@ _hidden yajl_gen_status libxl__yajl_gen_asciiz(yajl_gen hand, const char *str);
 _hidden yajl_gen_status libxl__yajl_gen_enum(yajl_gen hand, const char *str);
 
 typedef enum {
-    JSON_NULL,
-    JSON_BOOL,
-    JSON_INTEGER,
-    JSON_DOUBLE,
+    JSON_NULL    = (1 << 0),
+    JSON_BOOL    = (1 << 1),
+    JSON_INTEGER = (1 << 2),
+    JSON_DOUBLE  = (1 << 3),
     /* number is store in string, it's too big to be a long long or a double */
-    JSON_NUMBER,
-    JSON_STRING,
-    JSON_MAP,
-    JSON_ARRAY,
-    JSON_ANY
+    JSON_NUMBER  = (1 << 4),
+    JSON_STRING  = (1 << 5),
+    JSON_MAP     = (1 << 6),
+    JSON_ARRAY   = (1 << 7),
+    JSON_ANY     = 255 /* this is a mask of all values above, adjust as needed */
 } libxl__json_node_type;
 
 typedef struct libxl__json_object {
diff --git a/tools/libxl/libxl_json.c b/tools/libxl/libxl_json.c
index 361607f..6f1116f 100644
--- a/tools/libxl/libxl_json.c
+++ b/tools/libxl/libxl_json.c
@@ -363,7 +363,7 @@ const libxl__json_object *libxl__json_map_get(const char *key,
                 return NULL;
             if (strcmp(key, node->map_key) == 0) {
                 if (expected_type == JSON_ANY
-                    || (node->obj && node->obj->type == expected_type)) {
+                    || (node->obj && (node->obj->type & expected_type))) {
                     return node->obj;
                 } else {
                     return NULL;
-- 
1.7.10.4