Add json2c for including json in C files

Change-Id: I08d8f1c249d5612831fcbc66fe5d0caee4e3a73d
Signed-off-by: José Bollo <jose.bollo@iot.bzh>

2 files changed, 182 insertions, 0 deletions

diff --git a/src/genskel/CMakeLists.txt b/src/genskel/CMakeLists.txt
index ac1d1210..b1d63825 100644
--- a/src/genskel/CMakeLists.txt
+++ b/src/genskel/CMakeLists.txt
@@ -17,6 +17,14 @@
 ###########################################################################
 
 ADD_EXECUTABLE(afb-genskel genskel.c)
+ADD_EXECUTABLE(afb-exprefs exprefs.c)
+ADD_EXECUTABLE(afb-json2c json2c.c)
+
 TARGET_LINK_LIBRARIES(afb-genskel ${link_libraries})
+TARGET_LINK_LIBRARIES(afb-exprefs ${link_libraries})
+TARGET_LINK_LIBRARIES(afb-json2c ${link_libraries})
+
 INSTALL(TARGETS afb-genskel RUNTIME DESTINATION ${CMAKE_INSTALL_BINDIR})
+INSTALL(TARGETS afb-exprefs RUNTIME DESTINATION ${CMAKE_INSTALL_BINDIR})
+INSTALL(TARGETS afb-json2c  RUNTIME DESTINATION ${CMAKE_INSTALL_BINDIR})
 
diff --git a/src/genskel/json2c.c b/src/genskel/json2c.c
new file mode 100644
index 00000000..cb541bfd
--- /dev/null
+++ b/src/genskel/json2c.c
@@ -0,0 +1,174 @@
+/*
+ * Copyright (C) 2016, 2017 "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>
+
+#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)
+{
+	const char *a, *b;
+	char *desc, c, buf[3];
+	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);
+
+	len = pos = 0;
+	b = a;
+	while((c = *b++)) {
+		if (c == '"') {
+			buf[0] = '\\';
+			buf[1] = '"';
+			buf[2] = 0;
+		}
+		else if (c == '\\') {
+			switch ((c = *b++)) {
+			case 0:
+				b--;
+				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 (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++] = '"';
+	desc[len++] = '\n';
+	desc[len] = 0;
+	return desc;
+}
+
+/**
+ * process a file and prints its expansion on stdout
+ */
+void process(char *filename)
+{
+	char *desc;
+
+	/* 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 = make_desc(root);
+
+	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;
+}
+
+