devtools: Refactoring, bug fix, new IDL

The programs from devtools are rewritten to
use common improved code with bug fixes.

At the same time, the tool afb-genskel accept
a new JSON format for describing apis.

Change-Id: I38fd25be448bdc0339df63a570bddf53d37b9c3f
Signed-off-by: José Bollo <jose.bollo@iot.bzh>

12 files changed, 1007 insertions, 457 deletions

diff --git a/src/devtools/CMakeLists.txt b/src/devtools/CMakeLists.txt
index 6dfe788b..05edaffd 100644
--- a/src/devtools/CMakeLists.txt
+++ b/src/devtools/CMakeLists.txt
@@ -16,9 +16,9 @@
 # limitations under the License.
 ###########################################################################
 
-ADD_EXECUTABLE(afb-genskel genskel.c)
-ADD_EXECUTABLE(afb-exprefs exprefs.c)
-ADD_EXECUTABLE(afb-json2c json2c.c)
+ADD_EXECUTABLE(afb-genskel main-genskel.c exprefs.c getref.c json2c.c)
+ADD_EXECUTABLE(afb-exprefs main-exprefs.c exprefs.c getref.c)
+ADD_EXECUTABLE(afb-json2c main-json2c.c json2c.c)
 
 TARGET_LINK_LIBRARIES(afb-genskel ${link_libraries})
 TARGET_LINK_LIBRARIES(afb-exprefs ${link_libraries})
diff --git a/src/devtools/exprefs.c b/src/devtools/exprefs.c
index 4459f2c4..cfd39410 100644
--- a/src/devtools/exprefs.c
+++ b/src/devtools/exprefs.c
@@ -43,105 +43,91 @@
 #define _GNU_SOURCE
 #include <string.h>
 #include <stdio.h>
-#include <unistd.h>
 
 #include <json-c/json.h>
 
+#include "getref.h"
+#include "exprefs.h"
+
 /**
  * records path to the expanded node
  */
 struct path
 {
 	struct json_object *object;	/**< node being expanded */
-	struct path *upper;		/**< link to upper expanded nodes */
+	const struct path *upper;	/**< link to upper expanded nodes */
 };
 
 /**
- * root of the JSON being parsed
- */
-struct json_object *root;
-
-/**
- * Search for a reference of type "#/a/b/c" int the
- * parsed JSON object
+ * Returns the top object
  */
-struct json_object *search(const char *path)
+static inline struct json_object *top(const struct path *path)
 {
-	char *d;
-	struct json_object *i;
-
-	/* does it match #/ at the beginning? */
-	if (path[0] != '#' || (path[0] && path[1] != '/'))
-		return NULL;
-
-	/* search from root to target */
-	i = root;
-	d = strdupa(path+2);
-	d = strtok(d, "/");
-	while(i && d) {
-		if (!json_object_object_get_ex(i, d, &i))
-			return NULL;
-		d = strtok(NULL, "/");
-	}
-	return i;
+	while (path->upper)
+		path = path->upper;
+	return path->object;
 }
 
 /**
  * Expands the node designated by path and returns its expanded form
  */
-struct json_object *expand(struct path path)
+static struct json_object *expand(const struct path *upper)
 {
-	struct path *p;
-	struct json_object *o, *x;
+	struct path here;
+	struct json_object *object, *x;
 	int n, i;
 	struct json_object_iterator ji, jn;
 
 	/* expansion depends of the type of the node */
-	switch (json_object_get_type(path.object)) {
+	here.upper = upper;
+	object = upper->object;
+	switch (json_object_get_type(object)) {
 	case json_type_object:
 		/* for object, look if it contains a property "$ref" */
-		if (json_object_object_get_ex(path.object, "$ref", &o)) {
-			/* yes, reference, try to substitute its target */
-			if (!json_object_is_type(o, json_type_string)) {
-				fprintf(stderr, "found a $ref not being string. Is: %s\n", json_object_get_string(o));
+		if (json_object_object_get_ex(object, "$ref", &here.object)) {
+			/* check that "$ref" value is a string */
+			if (!json_object_is_type(here.object, json_type_string)) {
+				fprintf(stderr, "found a $ref not being string. Is: %s\n", json_object_get_string(here.object));
 				exit(1);
 			}
-			x = search(json_object_get_string(o));
-			if (!x) {
-				fprintf(stderr, "$ref not found. Was: %s\n", json_object_get_string(o));
+			/* yes, reference, try to substitute its target */
+			i = search$ref(top(upper), json_object_get_string(here.object), &x);
+			if (!i) {
+				fprintf(stderr, "$ref not found. Was: %s\n", json_object_get_string(here.object));
 				exit(1);
 			}
-			p = &path;
-			while(p) {
-				if (x == p->object) {
-					fprintf(stderr, "$ref recursive. Was: %s\n", json_object_get_string(o));
+			/* check not recursive */
+			upper = &here;
+			while(upper) {
+				if (x == upper->object) {
+					fprintf(stderr, "$ref recursive. Was: %s\n", json_object_get_string(here.object));
 					exit(1);
 				}
-				p = p->upper;
+				upper = upper->upper;
 			}
-			/* cool found, return a new instance of the target */
-			return json_object_get(x);
+			/* found. return a new instance of the target */
+			return x;
 		}
 		/* no, expand the values */
-		ji = json_object_iter_begin(path.object);
-		jn = json_object_iter_end(path.object);
+		ji = json_object_iter_begin(object);
+		jn = json_object_iter_end(object);
 		while (!json_object_iter_equal(&ji, &jn)) {
-			o = json_object_iter_peek_value(&ji);
-			x = expand((struct path){ .object = o, .upper = &path });
-			if (x != o)
-				json_object_object_add(path.object, json_object_iter_peek_name(&ji), x);
+			here.object = json_object_iter_peek_value(&ji);
+			x = expand(&here);
+			if (x != here.object)
+				json_object_object_add(object, json_object_iter_peek_name(&ji), json_object_get(x));
 			json_object_iter_next(&ji);
 		}
 		break;
 	case json_type_array:
 		/* expand the values of arrays */
 		i = 0;
-		n = (int)json_object_array_length(path.object);
+		n = (int)json_object_array_length(object);
 		while (i != n) {
-			o = json_object_array_get_idx(path.object, i);
-			x = expand((struct path){ .object = o, .upper = &path });
-			if (x != o)
-				json_object_array_put_idx(path.object, i, x);
+			here.object = json_object_array_get_idx(object, i);
+			x = expand(&here);
+			if (x != here.object)
+				json_object_array_put_idx(object, i, json_object_get(x));
 			i++;
 		}
 		break;
@@ -150,49 +136,62 @@ struct json_object *expand(struct path path)
 		break;
 	}
 	/* return the given node */
-	return path.object;
+	return object;
 }
 
-/**
- * process a file and prints its expansion on stdout
- */
-void process(char *filename)
+struct json_object *exp$refs(struct json_object *root)
 {
-	/* translate - */
-	if (!strcmp(filename, "-"))
-		filename = "/dev/stdin";
+	struct path top = { .object = root, .upper = NULL };
+	return expand(&top);
+}
 
-	/* check access */
-	if (access(filename, R_OK)) {
-		fprintf(stderr, "can't access file %s\n", filename);
-		exit(1);
-	}
+static int is_tree(struct json_object *object, const struct path *upper)
+{
+	struct path here;
+	int n, i;
+	struct json_object_iterator ji, jn;
 
-	/* read the file */
-	root = json_object_from_file(filename);
-	if (!root) {
-		fprintf(stderr, "reading file %s produced null\n", filename);
-		exit(1);
+	switch (json_object_get_type(object)) {
+	case json_type_object:
+	case json_type_array:
+		/* check recursive */
+		here.upper = upper;
+		while (upper) {
+			if (upper->object == object)
+				return 0;
+			upper = upper->upper;
+		}
+		here.object = object;
+		switch (json_object_get_type(object)) {
+		case json_type_object:
+			ji = json_object_iter_begin(object);
+			jn = json_object_iter_end(object);
+			while (!json_object_iter_equal(&ji, &jn)) {
+				if (!is_tree(json_object_iter_peek_value(&ji), &here))
+					return 0;
+				json_object_iter_next(&ji);
+			}
+			break;
+		case json_type_array:
+			i = 0;
+			n = (int)json_object_array_length(object);
+			while (i != n) {
+				if (!is_tree(json_object_array_get_idx(object, i), &here))
+					return 0;
+				i++;
+			}
+			break;
+		default:
+			break;
+		}
+		break;
+	default:
+		break;
 	}
-
-	/* expand */
-	root = expand((struct path){ .object = root, .upper = NULL });
-
-	/* print the result */
-	json_object_to_file_ext ("/dev/stdout", root, JSON_C_TO_STRING_PRETTY);
-
-	/* clean up */
-	json_object_put(root);
+	return 1;
 }
 
-/** process the list of files or stdin if none */
-int main(int ac, char **av)
+int exp$refs_is_tree(struct json_object *root)
 {
-	if (!*++av)
-		process("-");
-	else {
-		do { process(*av); } while(*++av);
-	}
-	return 0;
+	return is_tree(root, NULL);
 }
-
diff --git a/src/devtools/exprefs.h b/src/devtools/exprefs.h
new file mode 100644
index 00000000..8def4b67
--- /dev/null
+++ b/src/devtools/exprefs.h
@@ -0,0 +1,23 @@
+/*
+ * Copyright (C) 2016, 2017, 2018 "IoT.bzh"
+ * Author José Bollo <jose.bollo@iot.bzh>
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *   http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#pragma once
+
+struct json_object;
+
+extern struct json_object *exp$refs(struct json_object *root);
+extern int exp$refs_is_tree(struct json_object *root);
diff --git a/src/devtools/genskel.md b/src/devtools/genskel.md
new file mode 100644
index 00000000..8b137891
--- /dev/null
+++ b/src/devtools/genskel.md
@@ -0,0 +1 @@
+
diff --git a/src/devtools/getref.c b/src/devtools/getref.c
new file mode 100644
index 00000000..9e829dd5
--- /dev/null
+++ b/src/devtools/getref.c
@@ -0,0 +1,84 @@
+/*
+ * Copyright (C) 2016, 2017, 2018 "IoT.bzh"
+ * Author José Bollo <jose.bollo@iot.bzh>
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *   http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+/*
+ * This simple program expands the object { "$ref": "#/path/to/a/target" }
+ *
+ * For example:
+ *
+ *  {
+ *    "type":{
+ *      "a": "int",
+ *      "b": { "$ref": "#/type/a" }
+ *    }
+ *  }
+ *
+ * will be exapanded to
+ *
+ *  {
+ *    "type":{
+ *      "a": "int",
+ *      "b": "int"
+ *    }
+ *  }
+ *
+ * Invocation:   program  [file|-]...
+ *
+ * without arguments, it reads the input.
+ */
+
+#define _GNU_SOURCE
+#include <stdio.h>
+#include <string.h>
+
+#include <json-c/json.h>
+
+#include "getref.h"
+
+/**
+ * Search for a reference of type "#/a/b/c" int the
+ * parsed JSON root object
+ */
+int search$ref(struct json_object *root, const char *ref, struct json_object **result)
+{
+	char *d;
+	struct json_object *i;
+
+	/* does it match #/ at the beginning? */
+	if (ref[0] != '#' || (ref[0] && ref[1] != '/')) {
+		fprintf(stderr, "$ref invalid. Was: %s", ref);
+		return 0;
+	}
+
+	/* search from root to target */
+	i = root;
+	d = strdupa(ref+2);
+	d = strtok(d, "/");
+	while(i && d) {
+		if (!json_object_object_get_ex(i, d, &i))
+			return 0;
+		d = strtok(NULL, "/");
+	}
+	if (result)
+		*result = i;
+	return 1;
+}
+
+struct json_object *get$ref(struct json_object *root, const char *ref)
+{
+	struct json_object *result;
+	return search$ref(root, ref, &result) ? result : NULL;
+}
diff --git a/src/devtools/getref.h b/src/devtools/getref.h
new file mode 100644
index 00000000..afa3838a
--- /dev/null
+++ b/src/devtools/getref.h
@@ -0,0 +1,23 @@
+/*
+ * Copyright (C) 2016, 2017, 2018 "IoT.bzh"
+ * Author José Bollo <jose.bollo@iot.bzh>
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *   http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#pragma once
+
+struct json_object;
+
+extern int search$ref(struct json_object *root, const char *ref, struct json_object **result);
+extern struct json_object *get$ref(struct json_object *root, const char *ref);
diff --git a/src/devtools/idl-monitor.json b/src/devtools/idl-monitor.json
new file mode 100644
index 00000000..5afc29d0
--- /dev/null
+++ b/src/devtools/idl-monitor.json
@@ -0,0 +1,296 @@
+{
+  "afbidl": "0.1",
+  "info": {
+    "description": "monitoring of bindings and internals",
+    "title": "monitor",
+    "version": "1.0"
+  },
+  "generator": {
+    "genskel": {
+      "version": 2,
+      "prefix": "f_",
+      "postfix": "",
+      "preinit": null,
+      "init": null,
+      "onevent": null,
+      "scope": "static",
+      "private": true
+    }
+  },
+  "api": {
+    "name": "monitor",
+    "verbs": {
+      "get": {
+        "description": "Get monitoring data.",
+        "permissions": { "session": "check" },
+        "request": { "$ref": "#/schemas/get-request" },
+        "reply": { "$ref": "#/schemas/get-reply" }
+      },
+      "set": {
+        "description": "Set monitoring actions.",
+        "permissions": { "session": "check" },
+        "request": { "$ref": "#/schemas/set-request" },
+        "reply": { "$ref": "#/schemas/any" }
+      },
+      "trace": {
+        "description": "Set monitoring actions.",
+        "permissions": { "session": "check" },
+        "request": { "$ref": "#/schemas/trace-request" },
+        "reply": { "$ref": "#/schemas/any" }
+      },
+      "session": {
+        "description": "describes the session.",
+        "permissions": { "session": "check" },
+        "request": { "$ref": "#/schemas/session-request" },
+        "reply": { "$ref": "#/schemas/any" }
+      }
+    }
+  },
+  "schemas": {
+    "any": {
+      "title": "Any value",
+      "type": [ "null", "boolean", "object", "array", "number", "string" ]
+    },
+    "set-request": {
+      "type": "object",
+      "properties": {
+        "verbosity": { "$ref": "#/schemas/set-verbosity" }
+      }
+    },
+    "set-verbosity": {
+      "anyOf": [
+        { "$ref": "#/schemas/verbosity-map" },
+        { "$ref": "#/schemas/verbosity-level" }
+      ]
+    },
+    "get-request": {
+      "type": "object",
+      "properties": {
+        "verbosity": { "$ref": "#/schemas/get-verbosity" },
+        "apis": { "$ref": "#/schemas/get-apis" }
+      }
+    },
+    "get-reply": {
+      "type": "object",
+      "properties": {
+        "verbosity": { "$ref": "#/schemas/verbosity-map" },
+        "apis": { "type": "object" }
+      }
+    },
+    "get-verbosity": {
+      "anyOf": [
+        { "type": "boolean" },
+        { "type": "array", "items": { "type": "string" } },
+        { "type": "object" }
+      ]
+    },
+    "get-apis": {
+      "anyOf": [
+        { "type": "boolean" },
+        { "type": "array", "items": { "type": "string" } },
+        { "type": "object" }
+      ]
+    },
+    "verbosity-map": {
+      "type": "object",
+      "patternProperties": { "^.*$": { "$ref": "#/schemas/verbosity-level" } }
+    },
+    "verbosity-level": {
+      "enum": [ "debug", 3, "info", 2, "notice", "warning", 1, "error", 0 ]
+    },
+    "trace-request": {
+      "type": "object",
+      "properties": {
+        "add": { "$ref": "#/schemas/trace-add" },
+        "drop": { "$ref": "#/schemas/trace-drop" }
+      }
+    },
+    "trace-add": {
+      "anyOf": [
+        { "type": "array", "items": { "$ref": "#/schemas/trace-add-object" } },
+        { "$ref": "#/schemas/trace-add-any" }
+      ]
+    },
+    "trace-add-any": {
+      "anyOf": [
+        { "$ref": "#/schemas/trace-add-request" },
+        { "$ref": "#/schemas/trace-add-object" }
+      ]
+    },
+    "trace-add-object": {
+      "type": "object",
+      "properties": {
+        "name": { "type": "string", "description": "name of the generated event", "default": "trace" },
+        "tag": { "type": "string", "description": "tag for grouping traces", "default": "trace" },
+        "api": { "type": "string", "description": "api for requests, daemons and services" },
+        "verb": { "type": "string", "description": "verb for requests" },
+        "uuid": { "type": "string", "description": "uuid of session for requests" },
+        "pattern": { "type": "string", "description": "pattern for events" },
+        "request": { "$ref": "#/schemas/trace-add-request" },
+        "daemon": { "$ref": "#/schemas/trace-add-daemon" },
+        "service": { "$ref": "#/schemas/trace-add-service" },
+        "event": { "$ref": "#/schemas/trace-add-event" },
+        "session": { "$ref": "#/schemas/trace-add-session" },
+        "for": { "$ref": "#/schemas/trace-add" }
+      },
+      "examples": [
+        { "tag": "1", "for": [ "common", { "api": "xxx", "request": "*", "daemon": "*", "service": "*" } ] }
+      ]
+    },
+    "trace-add-request": {
+      "anyOf": [
+        { "type": "array", "items": { "$ref": "#/schemas/trace-request-names" } },
+        { "$ref": "#/schemas/trace-request-names" }
+      ]
+    },
+    "trace-request-names": {
+      "title": "name of traceable items of requests",
+      "enum": [
+        "*",
+        "addref",
+        "all",
+        "args",
+        "begin",
+        "common",
+        "context",
+        "context_get",
+        "context_set",
+        "end",
+        "event",
+        "extra",
+        "get",
+        "json",
+        "life",
+        "ref",
+	  "reply",
+        "result",
+        "session",
+        "session_close",
+        "session_set_LOA",
+        "simple",
+        "store",
+        "stores",
+        "subcall",
+        "subcall_result",
+        "subcalls",
+        "subcallsync",
+        "subcallsync_result",
+        "subscribe",
+        "unref",
+        "unstore",
+        "unsubscribe",
+        "vverbose"
+      ]
+    },
+    "trace-add-daemon": {
+      "anyOf": [
+        { "type": "array", "items": { "$ref": "#/schemas/trace-daemon-names" } },
+        { "$ref": "#/schemas/trace-daemon-names" }
+      ]
+    },
+    "trace-daemon-names": {
+      "title": "name of traceable items of daemons",
+      "enum": [
+        "*",
+        "all",
+        "common",
+        "event_broadcast_after",
+        "event_broadcast_before",
+        "event_make",
+        "extra",
+        "get_event_loop",
+        "get_system_bus",
+        "get_user_bus",
+        "queue_job",
+        "require_api",
+        "require_api_result",
+        "rootdir_get_fd",
+        "rootdir_open_locale",
+        "unstore_req",
+        "vverbose"
+      ]
+    },
+    "trace-add-service": {
+      "anyOf": [
+        { "type": "array", "items": { "$ref": "#/schemas/trace-service-names" } },
+        { "$ref": "#/schemas/trace-service-names" }
+      ]
+    },
+    "trace-service-names": {
+      "title": "name of traceable items of services",
+      "enum": [
+        "*",
+        "all",
+        "call",
+        "call_result",
+        "callsync",
+        "callsync_result",
+        "on_event_after",
+        "on_event_before",
+        "start_after",
+        "start_before"
+      ]
+    },
+    "trace-add-event": {
+      "anyOf": [
+        { "type": "array", "items": { "$ref": "#/schemas/trace-event-names" } },
+        { "$ref": "#/schemas/trace-event-names" }
+      ]
+    },
+    "trace-event-names": {
+      "title": "name of traceable items of events",
+      "enum": [
+        "*",
+        "all",
+        "broadcast_after",
+        "broadcast_before",
+        "common",
+        "create",
+        "drop",
+        "extra",
+        "name",
+        "push_after",
+        "push_before"
+      ]
+    },
+    "trace-add-session": {
+      "anyOf": [
+        { "type": "array", "items": { "$ref": "#/schemas/trace-session-names" } },
+        { "$ref": "#/schemas/trace-session-names" }
+      ]
+    },
+    "trace-session-names": {
+      "title": "name of traceable items for sessions",
+      "enum": [
+        "*",
+        "addref",
+        "all",
+        "close",
+        "common",
+        "create",
+        "destroy",
+        "renew",
+        "unref"
+      ]
+    },
+    "trace-drop": {
+      "anyOf": [
+        { "type": "boolean" },
+        {
+          "type": "object",
+          "properties": {
+            "event": { "anyOf": [  { "type": "string" }, { "type": "array", "items": "string" } ] },
+            "tag": { "anyOf": [  { "type": "string" }, { "type": "array", "items": "string" } ] },
+            "uuid": { "anyOf": [  { "type": "string" }, { "type": "array", "items": "string" } ] }
+          }
+        }
+      ]
+    },
+    "session-request": {
+      "type": "object",
+      "properties": {
+        "refresh-token": { "type": "boolean" }
+      }
+    }
+  }
+}
diff --git a/src/devtools/json2c.c b/src/devtools/json2c.c
index 9bb9e9bf..c26ef84a 100644
--- a/src/devtools/json2c.c
+++ b/src/devtools/json2c.c
@@ -42,133 +42,141 @@
 
 #define _GNU_SOURCE
 #include <string.h>
+#include <limits.h>
+#include <assert.h>
 #include <stdio.h>
-#include <unistd.h>
 
 #include <json-c/json.h>
 
-#define oom(x) do{if(!(x)){fprintf(stderr,"out of memory\n");exit(1);}}while(0)
-
-/**
- * root of the JSON being parsed
- */
-struct json_object *root = NULL;
-
-char *make_desc(struct json_object *o)
+static size_t s2c(const char *str, const char *prefix, int width, int lprf, char *out)
 {
-	const char *a, *b;
-	char *desc, c, buf[3];
+	char c, buf[4];
 	size_t len;
-	int i, pos, e;
-
-	a = b = json_object_to_json_string_ext(root, 0);
-	len = 1;
-	while((c = *b++)) {
-		len += 1 + ('"' == c);
-	}
-
-	len += 7 * (1 + len / 72);
-	desc = malloc(len);
-	oom(desc);
+	int i, pos;
 
+#define P(x) do{ if (out) out[len] = (x); len++; pos++; }while(0)
+	/* translate the string */
 	len = pos = 0;
-	b = a;
-	while((c = *b++)) {
-		if (c == '"') {
+	for(;;) {
+		/* get the char to convert */
+		c = *str++;
+
+		/* set buf with next char */
+		switch(c) {
+		case '\\':
+			c = *str++;
+			if (c) {
+				if (c == '/') {
+					/* remove ugly \/ put by json-c */
+					buf[0] = '/';
+					buf[1] = 0;
+				} else {
+					buf[0] = '\\';
+					buf[1] = c;
+					buf[2] = 0;
+				}
+				break;
+			}
+			/*@fallthrough@*/
+		case 0:
+			if (!len) P('"');
+			if (!len || pos) {
+				P('"');
+				if (prefix) P('\n');
+			}
+			P(0);
+			return len;
+		case '"':
 			buf[0] = '\\';
 			buf[1] = '"';
 			buf[2] = 0;
-		}
-		else if (c == '\\') {
-			switch ((c = *b++)) {
-			case '/':
-				buf[0] = '/';
-				buf[1] = 0;
-				break;
-			case 0:
-				b--;
-				/*@fallthrough@*/
-			default:
+			break;
+		case '\n':
+			buf[0] = '\\';
+			buf[1] = 'n';
+			buf[2] = 0;
+			break;
+		case '\t':
+			buf[0] = '\\';
+			buf[1] = 't';
+			buf[2] = 0;
+			break;
+		default:
+			if (0 < c && c < ' ') {
 				buf[0] = '\\';
-				buf[1] = c;
-				buf[2] = 0;
+				buf[1] = (char)('0' + ((c >> 3) & 7));
+				buf[2] = (char)('0' + ((c >> 0) & 7));
+				buf[3] = 0;
+			} else {
+				buf[0] = c;
+				buf[1] = 0;
 				break;
 			}
+			break;
 		}
-		else {
-			buf[0] = c;
-			buf[1] = 0;
+		/* add the char in the output */
+		if (pos == 0) {
+			for(i = 0 ; i < lprf ; i++)
+				P(prefix[i]);
+			P('"');
 		}
-		i = e = 0;
-		while (buf[i]) {
-			if (pos >= 77 && !e) {
-				desc[len++] = '"';
-				desc[len++] = '\n';
-				pos = 0;
-			}
-			if (pos == 0) {
-				desc[len++] = ' ';
-				desc[len++] = ' ';
-				desc[len++] = ' ';
-				desc[len++] = ' ';
-				desc[len++] = '"';
-				pos = 5;
-			}
-			c = buf[i++];
-			desc[len++] = c;
-			e = !e && c == '\\';
-			pos++;
+		for(i = 0 ; buf[i] ; i++)
+			P(buf[i]);
+		if (pos >= width - 1) {
+			P('"');
+			P('\n');
+			pos = 0;
 		}
 	}
-	desc[len++] = '"';
-	desc[len++] = '\n';
-	desc[len] = 0;
-	return desc;
+	while(c);
+#undef P
 }
 
-/**
- * process a file and prints its expansion on stdout
- */
-void process(char *filename)
+char *str2c(const char *str, const char *prefix, int width)
 {
-	char *desc;
+	size_t len;
+	int lprf;
+	char *out;
 
-	/* translate - */
-	if (!strcmp(filename, "-"))
-		filename = "/dev/stdin";
+	/* ensure defaults */
+	len = prefix ? strlen(prefix) : 0;
+	lprf = len > INT_MAX ? INT_MAX : (int)len;
+	width = width <= 0 || width - 2 <= lprf ? INT_MAX : width;
 
-	/* check access */
-	if (access(filename, R_OK)) {
-		fprintf(stderr, "can't access file %s\n", filename);
-		exit(1);
-	}
+	/* compute final size*/
+	len = s2c(str, prefix, width, lprf, NULL);
 
-	/* read the file */
-	root = json_object_from_file(filename);
-	if (!root) {
-		fprintf(stderr, "reading file %s produced null\n", filename);
-		exit(1);
-	}
+	/* allocate the memory */
+	out = malloc(len);
+	if (!out)
+		return NULL;
 
-	/* create the description */
-	desc = make_desc(root);
+	/* make the output */
+	s2c(str, prefix, width, lprf, out);
+	return out;
+}
 
-	printf("%s", desc);
+char *str2c_std(const char *str)
+{
+	return str2c(str, "\t", 71);
+}
 
-	/* clean up */
-	json_object_put(root);
-	free(desc);
+char *str2c_inl(const char *str)
+{
+	return str2c(str, 0, 0);
 }
 
-/** process the list of files or stdin if none */
-int main(int ac, char **av)
+char *json2c(struct json_object *object, const char *prefix, int width)
 {
-	if (!*++av)
-		process("-");
-	else {
-		do { process(*av); } while(*++av);
-	}
-	return 0;
+	return str2c(json_object_to_json_string_ext(object, 0), prefix, width);
 }
 
+char *json2c_std(struct json_object *object)
+{
+	return str2c_std(json_object_to_json_string_ext(object, 0));
+}
 
+char *json2c_inl(struct json_object *object)
+{
+	return str2c_inl(json_object_to_json_string_ext(object, 0));
+}
diff --git a/src/devtools/json2c.h b/src/devtools/json2c.h
new file mode 100644
index 00000000..9c4e7e26
--- /dev/null
+++ b/src/devtools/json2c.h
@@ -0,0 +1,28 @@
+/*
+ * Copyright (C) 2016, 2017, 2018 "IoT.bzh"
+ * Author José Bollo <jose.bollo@iot.bzh>
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *   http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#pragma once
+
+struct json_object;
+
+extern char *str2c(const char *str, const char *prefix, int width);
+extern char *str2c_std(const char *str);
+extern char *str2c_inl(const char *str);
+
+extern char *json2c(struct json_object *object, const char *prefix, int width);
+extern char *json2c_std(struct json_object *object);
+extern char *json2c_inl(struct json_object *object);
diff --git a/src/devtools/main-exprefs.c b/src/devtools/main-exprefs.c
new file mode 100644
index 00000000..5a114a2a
--- /dev/null
+++ b/src/devtools/main-exprefs.c
@@ -0,0 +1,102 @@
+/*
+ * Copyright (C) 2016, 2017, 2018 "IoT.bzh"
+ * Author José Bollo <jose.bollo@iot.bzh>
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *   http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+/*
+ * This simple program expands the object { "$ref": "#/path/to/a/target" }
+ *
+ * For example:
+ *
+ *  {
+ *    "type":{
+ *      "a": "int",
+ *      "b": { "$ref": "#/type/a" }
+ *    }
+ *  }
+ *
+ * will be exapanded to
+ *
+ *  {
+ *    "type":{
+ *      "a": "int",
+ *      "b": "int"
+ *    }
+ *  }
+ *
+ * Invocation:   program  [file|-]...
+ *
+ * without arguments, it reads the input.
+ */
+
+#define _GNU_SOURCE
+#include <string.h>
+#include <stdio.h>
+#include <unistd.h>
+
+#include <json-c/json.h>
+
+#include "exprefs.h"
+
+/**
+ * process a file and prints its expansion on stdout
+ */
+void process(char *filename)
+{
+	struct json_object *root;
+
+	/* translate - */
+	if (!strcmp(filename, "-"))
+		filename = "/dev/stdin";
+
+	/* check access */
+	if (access(filename, R_OK)) {
+		fprintf(stderr, "can't access file %s\n", filename);
+		exit(1);
+	}
+
+	/* read the file */
+	root = json_object_from_file(filename);
+	if (!root) {
+		fprintf(stderr, "reading file %s produced null\n", filename);
+		exit(1);
+	}
+
+	/* expand */
+	root = exp$refs(root);
+
+	/* check if tree */
+	if (!exp$refs_is_tree(root)) {
+		fprintf(stderr, "expansion of %s doesn't produce a tree\n", filename);
+		exit(1);
+	}
+
+	/* print the result */
+	json_object_to_file_ext ("/dev/stdout", root, JSON_C_TO_STRING_PRETTY);
+
+	/* clean up */
+	json_object_put(root);
+}
+
+/** process the list of files or stdin if none */
+int main(int ac, char **av)
+{
+	if (!*++av)
+		process("-");
+	else {
+		do { process(*av); } while(*++av);
+	}
+	return 0;
+}
+
diff --git a/src/devtools/genskel.c b/src/devtools/main-genskel.c
index 80dcd381..bad7ee97 100644
--- a/src/devtools/genskel.c
+++ b/src/devtools/main-genskel.c
@@ -14,31 +14,6 @@
  * See the License for the specific language governing permissions and
  * limitations under the License.
  */
-/*
- * This simple program expands the object { "$ref": "#/path/to/a/target" }
- *
- * For example:
- *
- *  {
- *    "type":{
- *      "a": "int",
- *      "b": { "$ref": "#/type/a" }
- *    }
- *  }
- *
- * will be exapanded to
- *
- *  {
- *    "type":{
- *      "a": "int",
- *      "b": "int"
- *    }
- *  }
- *
- * Invocation:   program  [file|-]...
- *
- * without arguments, it reads the input.
- */
 
 #define _GNU_SOURCE
 #include <string.h>
@@ -48,17 +23,12 @@
 
 #include <json-c/json.h>
 
-#define T(x)   ((x) && *(x))
-#define oom(x) do{if(!(x)){fprintf(stderr,"out of memory\n");exit(1);}}while(0)
+#include "getref.h"
+#include "exprefs.h"
+#include "json2c.h"
 
-/**
- * records path to the expanded node
- */
-struct path
-{
-	struct json_object *object;	/**< node being expanded */
-	struct path *upper;		/**< link to upper expanded nodes */
-};
+#define TEST(x)   ((x) && *(x))
+#define OOM(x) do{if(!(x)){fprintf(stderr,"out of memory\n");exit(1);}}while(0)
 
 /**
  * root of the JSON being parsed
@@ -77,103 +47,17 @@ const char *postfix = NULL;
 const char *provideclass = NULL;
 const char *requireclass = NULL;
 const char *requireapi = NULL;
+const char *info = NULL;
 char *capi = NULL;
 int priv = -1;
 int noconc = -1;
 int cpp = 0;
+enum idl {
+	idl_afbidl = 0,
+	idl_openapi = 1
+} idl = idl_openapi;
 
-/**
- * Search for a reference of type "#/a/b/c" in the
- * parsed JSON object (root)
- */
-struct json_object *search(const char *path)
-{
-	char *d;
-	struct json_object *i;
-
-	/* does it match #/ at the beginning? */
-	if (path[0] != '#' || (path[0] && path[1] != '/'))
-		return NULL;
-
-	/* search from root to target */
-	i = root;
-	d = strdupa(path+2);
-	d = strtok(d, "/");
-	while(i && d) {
-		if (!json_object_object_get_ex(i, d, &i))
-			return NULL;
-		d = strtok(NULL, "/");
-	}
-	return i;
-}
-
-/**
- * Expands the node designated by path and returns its expanded form
- */
-struct json_object *expand_$ref(struct path path)
-{
-	struct path *p;
-	struct json_object *o, *x;
-	int n, i;
-	struct json_object_iterator ji, jn;
-
-	/* expansion depends of the type of the node */
-	switch (json_object_get_type(path.object)) {
-	case json_type_object:
-		/* for object, look if it contains a property "$ref" */
-		if (json_object_object_get_ex(path.object, "$ref", &o)) {
-			/* yes, reference, try to substitute its target */
-			if (!json_object_is_type(o, json_type_string)) {
-				fprintf(stderr, "found a $ref not being string. Is: %s\n", json_object_get_string(o));
-				exit(1);
-			}
-			x = search(json_object_get_string(o));
-			if (!x) {
-				fprintf(stderr, "$ref not found. Was: %s\n", json_object_get_string(o));
-				exit(1);
-			}
-			p = &path;
-			while(p) {
-				if (x == p->object) {
-					fprintf(stderr, "$ref recursive. Was: %s\n", json_object_get_string(o));
-					exit(1);
-				}
-				p = p->upper;
-			}
-			/* cool found, return a new instance of the target */
-			return json_object_get(x);
-		}
-		/* no, expand the values */
-		ji = json_object_iter_begin(path.object);
-		jn = json_object_iter_end(path.object);
-		while (!json_object_iter_equal(&ji, &jn)) {
-			o = json_object_iter_peek_value(&ji);
-			x = expand_$ref((struct path){ .object = o, .upper = &path });
-			if (x != o)
-				json_object_object_add(path.object, json_object_iter_peek_name(&ji), x);
-			json_object_iter_next(&ji);
-		}
-		break;
-	case json_type_array:
-		/* expand the values of arrays */
-		i = 0;
-		n = (int)json_object_array_length(path.object);
-		while (i != n) {
-			o = json_object_array_get_idx(path.object, i);
-			x = expand_$ref((struct path){ .object = o, .upper = &path });
-			if (x != o)
-				json_object_array_put_idx(path.object, i, x);
-			i++;
-		}
-		break;
-	default:
-		/* otherwise no expansion */
-		break;
-	}
 
-	/* return the given node */
-	return path.object;
-}
 
 /* create c name by replacing non alpha numeric characters with underscores */
 char *cify(const char *str)
@@ -188,97 +72,14 @@ char *cify(const char *str)
 	return r;
 }
 
-/* format the specification as a C string */
-char *make_info(const char *text, int split)
-{
-	const char *a, *b;
-	char *desc, c, buf[3] = {0};
-	size_t len;
-	int i, pos, e;
-
-	/* estimated length */
-	a = b = text;
-	len = 1;
-	while((c = *b++)) {
-		len += 1 + ('"' == c);
-	}
-
-	len += 7 * (1 + len / 72);
-	desc = malloc(len);
-	oom(desc);
-
-	len = pos = 0;
-	if (!split)
-		desc[len++] = '"';
-	b = a;
-	while((c = *b++)) {
-		if (c == '"') {
-			buf[0] = '\\';
-			buf[1] = '"';
-			buf[2] = 0;
-		}
-		else if (c == '\\') {
-			switch ((c = *b++)) {
-			case 0:
-				b--;
-				buf[0] = 0;
-				break;
-			case '/':
-				buf[0] = '/';
-				buf[1] = 0;
-				break;
-			default:
-				buf[0] = '\\';
-				buf[1] = c;
-				buf[2] = 0;
-				break;
-			}
-		}
-		else {
-			buf[0] = c;
-			buf[1] = 0;
-		}
-		i = e = 0;
-		while (buf[i]) {
-			if (split) {
-				if (pos >= 77 && !e) {
-					desc[len++] = '"';
-					desc[len++] = '\n';
-					pos = 0;
-				}
-				if (pos == 0) {
-					desc[len++] = ' ';
-					desc[len++] = ' ';
-					desc[len++] = ' ';
-					desc[len++] = ' ';
-					desc[len++] = '"';
-					pos = 5;
-				}
-			}
-			c = buf[i++];
-			desc[len++] = c;
-			e = !e && c == '\\';
-			pos++;
-		}
-	}
-	desc[len++] = '"';
-	if (split)
-		desc[len++] = '\n';
-	desc[len] = 0;
-	return desc;
-}
-
-/* make the description of the object */
-char *make_desc(struct json_object *o)
-{
-	return make_info(json_object_to_json_string_ext(o, 0), 1);
-}
-
 /* get the permission odescription if set */
 struct json_object *permissions_of_verb(struct json_object *obj)
 {
 	struct json_object *x, *y;
 
+	if (idl == idl_afbidl)
+		return json_object_object_get_ex(obj, "permissions", &x) ? x : NULL;
+
 	if (json_object_object_get_ex(obj, "x-permissions", &x))
 		return x;
 
@@ -540,7 +341,7 @@ void print_verb(const char *name)
 
 void print_declare_verb(const char *name, struct json_object *obj)
 {
-	if (T(scope))
+	if (TEST(scope))
 		printf("%s ", scope);
 	printf("void ");
 	print_verb(name);
@@ -569,7 +370,7 @@ void print_struct_verb(const char *name, struct json_object *obj)
 		"        .auth = %s,\n"
 		"        .info = %s,\n"
 		, p && decl_perm(p) ? json_object_get_string(decl_perm(p)) : "NULL"
-		, info ? make_info(info, 0) : "NULL"
+		, info ? str2c_inl(info) : "NULL"
 	);
 	if (version == 3)
 		printf(
@@ -590,14 +391,60 @@ void print_struct_verb(const char *name, struct json_object *obj)
 	);
 }
 
-void enum_verbs(void (*func)(const char *name, struct json_object *obj))
+void getvarbool(int *var, const char *path, int defval)
+{
+	struct json_object *o;
+
+	if (*var != 0 && *var != 1) {
+		o = get$ref(root, path);
+		if (o && json_object_is_type(o, json_type_boolean))
+			*var = json_object_get_boolean(o);
+		else
+			*var = !!defval;
+	}
+}
+
+void getvar(const char **var, const char *path, const char *defval)
+{
+	struct json_object *o;
+
+	if (!*var) {
+		o = get$ref(root, path);
+		if (o && json_object_is_type(o, json_type_string))
+			*var = json_object_get_string(o);
+		else
+			*var = defval;
+	}
+}
+
+/******************************************************************************/
+
+void openapi_getvars()
+{
+	getvar(&api, "#/info/x-binding-c-generator/api", NULL);
+	getvar(&preinit, "#/info/x-binding-c-generator/preinit", NULL);
+	getvar(&init, "#/info/x-binding-c-generator/init", NULL);
+	getvar(&onevent, "#/info/x-binding-c-generator/onevent", NULL);
+	getvar(&scope, "#/info/x-binding-c-generator/scope", "static");
+	getvar(&prefix, "#/info/x-binding-c-generator/prefix", "afb_verb_");
+	getvar(&postfix, "#/info/x-binding-c-generator/postfix", "_cb");
+	getvar(&provideclass, "#/info/x-binding-c-generator/provide-class", NULL);
+	getvar(&requireclass, "#/info/x-binding-c-generator/require-class", NULL);
+	getvar(&requireapi, "#/info/x-binding-c-generator/require-api", NULL);
+	getvarbool(&priv, "#/info/x-binding-c-generator/private", 0);
+	getvarbool(&noconc, "#/info/x-binding-c-generator/noconcurrency", 0);
+	getvar(&api, "#/info/title", "?");
+	getvar(&info, "#/info/description", NULL);
+}
+
+void openapi_enum_verbs(void (*func)(const char *name, struct json_object *obj))
 {
 	struct json_object_iterator ji, jn;
 	struct json_object *paths, *obj;
 	const char *name;
 
 	/* search the verbs */
-	paths = search("#/paths");
+	paths = get$ref(root, "#/paths");
 	if (!paths)
 		return;
 
@@ -613,29 +460,63 @@ void enum_verbs(void (*func)(const char *name, struct json_object *obj))
 	}
 }
 
-void getvarbool(int *var, const char *path, int defval)
+/******************************************************************************/
+
+void afbidl_getvars()
 {
-	struct json_object *o;
+	getvar(&preinit, "#/generator/genskel/preinit", NULL);
+	getvar(&init, "#/generator/genskel/init", NULL);
+	getvar(&onevent, "#/generator/genskel/onevent", NULL);
+	getvar(&scope, "#/generator/genskel/scope", "static");
+	getvar(&prefix, "#/generator/genskel/prefix", "afb_verb_");
+	getvar(&postfix, "#/generator/genskel/postfix", "_cb");
+	getvar(&provideclass, "#/generator/genskel/provide-class", NULL);
+	getvar(&requireclass, "#/generator/genskel/require-class", NULL);
+	getvar(&requireapi, "#/generator/genskel/require-api", NULL);
+	getvarbool(&priv, "#/generator/genskel/private", 0);
+	getvarbool(&noconc, "#/generator/genskel/noconcurrency", 0);
+	getvar(&api, "#/api/name", NULL);
+	getvar(&api, "#/info/title", "?");
+	getvar(&info, "#/info/description", NULL);
+}
 
-	if (*var != 0 && *var != 1) {
-		o = search(path);
-		if (o && json_object_is_type(o, json_type_boolean))
-			*var = json_object_get_boolean(o);
-		else
-			*var = !!defval;
+void afbidl_enum_verbs(void (*func)(const char *name, struct json_object *obj))
+{
+	struct json_object_iterator ji, jn;
+	struct json_object *verbs, *obj;
+	const char *name;
+
+	/* search the verbs */
+	verbs = get$ref(root, "#/api/verbs");
+	if (!verbs)
+		return;
+
+	/* list the verbs and sort it */
+	ji = json_object_iter_begin(verbs);
+	jn = json_object_iter_end(verbs);
+	while (!json_object_iter_equal(&ji, &jn)) {
+		name = json_object_iter_peek_name(&ji);
+		obj = json_object_iter_peek_value(&ji);
+		func(name, obj);
+		json_object_iter_next(&ji);
 	}
 }
 
-void getvar(const char **var, const char *path, const char *defval)
+/******************************************************************************/
+
+void detectidl()
 {
 	struct json_object *o;
 
-	if (!*var) {
-		o = search(path);
-		if (o && json_object_is_type(o, json_type_string))
-			*var = json_object_get_string(o);
-		else
-			*var = defval;
+	o = get$ref(root, "#/openapi");
+	if (o) {
+		idl = idl_openapi;
+		return;
+	}
+	o = get$ref(root, "#/afbidl");
+	if (o) {
+		idl = idl_afbidl;
+		return;
 	}
 }
 
@@ -645,7 +526,9 @@ void getvar(const char **var, const char *path, const char *defval)
 void process(char *filename)
 {
 	char *desc;
-	const char *info;
+
+	void (*getvars)();
+	void (*enum_verbs)(void (*)(const char*, struct json_object*));
 
 	/* translate - */
 	if (!strcmp(filename, "-"))
@@ -664,28 +547,28 @@ void process(char *filename)
 		exit(1);
 	}
 
-	/* create the description */
-	desc = make_desc(root);
+	/* create the description (before expanding $ref ) */
+	desc = json2c_std(root);
 
 	/* expand references */
-	root = expand_$ref((struct path){ .object = root, .upper = NULL });
+	root = exp$refs(root);
+
+	/* detect the idl */
+	detectidl();
+	switch(idl) {
+	default:
+	case idl_afbidl:
+		getvars = afbidl_getvars;
+		enum_verbs = afbidl_enum_verbs;
+		break;
+	case idl_openapi:
+		getvars = openapi_getvars;
+		enum_verbs = openapi_enum_verbs;
+		break;
+	}
 
 	/* get some names */
-	getvar(&api, "#/info/x-binding-c-generator/api", NULL);
-	getvar(&preinit, "#/info/x-binding-c-generator/preinit", NULL);
-	getvar(&init, "#/info/x-binding-c-generator/init", NULL);
-	getvar(&onevent, "#/info/x-binding-c-generator/onevent", NULL);
-	getvar(&scope, "#/info/x-binding-c-generator/scope", "static");
-	getvar(&prefix, "#/info/x-binding-c-generator/prefix", "afb_verb_");
-	getvar(&postfix, "#/info/x-binding-c-generator/postfix", "_cb");
-	getvar(&provideclass, "#/info/x-binding-c-generator/provide-class", NULL);
-	getvar(&requireclass, "#/info/x-binding-c-generator/require-class", NULL);
-	getvar(&requireapi, "#/info/x-binding-c-generator/require-api", NULL);
-	getvarbool(&priv, "#/info/x-binding-c-generator/private", 0);
-	getvarbool(&noconc, "#/info/x-binding-c-generator/noconcurrency", 0);
-	getvar(&api, "#/info/title", "?");
-	info = NULL;
-	getvar(&info, "#/info/description", NULL);
+	getvars();
 	capi = cify(api);
 
 	/* get the API name */
@@ -727,22 +610,22 @@ void process(char *filename)
 		);
 	printf(
 		"\n"
-		"	}\n"
+		"    }\n"
 		"};\n"
 	);
 
-	if (T(preinit) || T(init) || T(onevent)) {
+	if (TEST(preinit) || TEST(init) || TEST(onevent)) {
 		printf("\n");
-		if (T(preinit)) {
-			if (T(scope)) printf("%s ", scope);
+		if (TEST(preinit)) {
+			if (TEST(scope)) printf("%s ", scope);
 			printf("int %s(%s);\n", preinit, version==3 ? "afb_api_t api" : "");
 		}
-		if (T(init)) {
-			if (T(scope)) printf("%s ", scope);
+		if (TEST(init)) {
+			if (TEST(scope)) printf("%s ", scope);
 			printf("int %s(%s);\n", init, version==3 ? "afb_api_t api" : "");
 		}
-		if (T(onevent)) {
-			if (T(scope)) printf("%s ", scope);
+		if (TEST(onevent)) {
+			if (TEST(scope)) printf("%s ", scope);
 			printf("void %s(%sconst char *event, struct json_object *object);\n",
 					onevent, version==3 ? "afb_api_t api, " : "");
 		}
@@ -764,11 +647,11 @@ void process(char *filename)
 		, priv ? capi : ""
 		, api
 		, capi
-		, info ? make_info(info, 0) : "NULL"
+		, info ? str2c_inl(info) : "NULL"
 		, capi
-		, T(preinit) ? preinit : "NULL"
-		, T(init) ? init : "NULL"
-		, T(onevent) ? onevent : "NULL"
+		, TEST(preinit) ? preinit : "NULL"
+		, TEST(init) ? init : "NULL"
+		, TEST(onevent) ? onevent : "NULL"
 	);
 
 
@@ -778,9 +661,9 @@ void process(char *filename)
 			"    .provide_class = %s%s%s,\n"
 			"    .require_class = %s%s%s,\n"
 			"    .require_api = %s%s%s,\n"
-			, T(provideclass) ? "\"" : "", T(provideclass) ? provideclass : "NULL", T(provideclass) ? "\"" : ""
-			, T(requireclass) ? "\"" : "", T(requireclass) ? requireclass : "NULL", T(requireclass) ? "\"" : ""
-			, T(requireapi) ? "\"" : "", T(requireapi) ? requireapi : "NULL", T(requireapi) ? "\"" : ""
+			, TEST(provideclass) ? "\"" : "", TEST(provideclass) ? provideclass : "NULL", TEST(provideclass) ? "\"" : ""
+			, TEST(requireclass) ? "\"" : "", TEST(requireclass) ? requireclass : "NULL", TEST(requireclass) ? "\"" : ""
+			, TEST(requireapi) ? "\"" : "", TEST(requireapi) ? requireapi : "NULL", TEST(requireapi) ? "\"" : ""
 		);
 
 
diff --git a/src/devtools/main-json2c.c b/src/devtools/main-json2c.c
new file mode 100644
index 00000000..eb0c7a05
--- /dev/null
+++ b/src/devtools/main-json2c.c
@@ -0,0 +1,103 @@
+/*
+ * Copyright (C) 2016, 2017, 2018 "IoT.bzh"
+ * Author José Bollo <jose.bollo@iot.bzh>
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *   http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+/*
+ * This simple program expands the object { "$ref": "#/path/to/a/target" }
+ *
+ * For example:
+ *
+ *  {
+ *    "type":{
+ *      "a": "int",
+ *      "b": { "$ref": "#/type/a" }
+ *    }
+ *  }
+ *
+ * will be exapanded to
+ *
+ *  {
+ *    "type":{
+ *      "a": "int",
+ *      "b": "int"
+ *    }
+ *  }
+ *
+ * Invocation:   program  [file|-]...
+ *
+ * without arguments, it reads the input.
+ */
+
+#define _GNU_SOURCE
+#include <string.h>
+#include <stdio.h>
+#include <unistd.h>
+
+#include <json-c/json.h>
+
+#include "json2c.h"
+
+/**
+ * process a file and prints its expansion on stdout
+ */
+void process(char *filename)
+{
+	char *desc;
+	struct json_object *root;
+
+	/* translate - */
+	if (!strcmp(filename, "-"))
+		filename = "/dev/stdin";
+
+	/* check access */
+	if (access(filename, R_OK)) {
+		fprintf(stderr, "can't access file %s\n", filename);
+		exit(1);
+	}
+
+	/* read the file */
+	root = json_object_from_file(filename);
+	if (!root) {
+		fprintf(stderr, "reading file %s produced null\n", filename);
+		exit(1);
+	}
+
+	/* create the description */
+	desc = json2c_std(root);
+	if (!desc) {
+		fprintf(stderr, "out of memory\n");
+		exit(1);
+	}
+
+	/* print the description */
+	printf("%s", desc);
+
+	/* clean up */
+	json_object_put(root);
+	free(desc);
+}
+
+/** process the list of files or stdin if none */
+int main(int ac, char **av)
+{
+	if (!*++av)
+		process("-");
+	else {
+		do { process(*av); } while(*++av);
+	}
+	return 0;
+}
+
+