Core: add references handling macros

* lasso/utils.h:
  - add macro lasso_transfer_string and lasso_transfer_gobject,
    to transfer ownership of such objects without copying or
    their changing reference count. The old containing variable is
    NULLed.
  - lasso_list_add_gobject,lasso_list_add_new_gobject: test if the added
    object is a GObject, if not do not add it and print a warning.
  - lasso_check_type_equality: this macro use special builtin functions
    only with GCC (typeof and __builtin_types_compatible_p) and do
    metaprogramming using anonymous enumeration type to make compile
    time assertions. It is used
 -  add macros to release XPathObject XPathContext, macro constructor to
    make reference transfert macros (free dest, nullify dest, copy src
    to dest without increasing refcount, nullify src), add a macro to
    transfert xpath objects.

1 files changed, 102 insertions, 17 deletions

diff --git a/lasso/utils.h b/lasso/utils.h
index 2d9d6382..8a58f95e 100644
--- a/lasso/utils.h
+++ b/lasso/utils.h
@@ -27,6 +27,19 @@
 
 #include <glib.h>
 
+#ifdef LASSO_DEBUG
+#ifdef __GNUC__
+#define lasso_check_type_equality(a,b) \
+	{ \
+		enum { TYPE_MISMATCH = (1 / __builtin_types_compatible_p(typeof(a), typeof(b))) }; \
+	}
+#else
+#define lasso_check_type_equality(a,b)
+#endif
+#else
+#define lasso_check_type_equality(a,b)
+#endif
+
 /* Assignment and list appending */
 #define lasso_assign_string(dest,src) \
 	{ \
@@ -43,6 +56,7 @@
 
 #define lasso_assign_gobject(dest,src) \
 	{ \
+		lasso_check_type_equality(dest, src); \
 		if (src) \
 			g_object_ref(src); \
 		if (dest) \
@@ -52,6 +66,7 @@
 
 #define lasso_assign_new_gobject(dest,src) \
 	{ \
+		lasso_check_type_equality(dest, src); \
 		if (dest) \
 			g_object_unref(dest); \
 		dest = (void*)(src); \
@@ -59,29 +74,58 @@
 
 #define lasso_assign_node(dest,src) \
 	{ \
+		lasso_check_type_equality(dest, src); \
 		if (dest) \
 			xmlFreeNode(dest); \
 		dest = xmlCopyNode(src, 1); \
 	}
 
+#define lasso_list_add(dest, src) \
+	{ \
+		lasso_check_type_equality(src, void*); \
+		dest = g_list_append(dest, src); \
+	}
+
+#define lasso_list_add_non_null(dest, src) \
+	{ \
+		lasso_check_type_equality(src, void*); \
+		if (src != NULL) { \
+			dest = g_list_append(dest, src); \
+		} else { \
+			g_critical("Adding a NULL value to a non-NULL content list: dest=%s src=%s", #dest, #src); \
+		} \
+	}
+
 #define lasso_list_add_string(dest, src) \
 	{ \
+		lasso_check_type_equality(dest, GList*); \
+		lasso_check_type_equality(src, gchar*); \
 		(dest) = g_list_append((dest), g_strdup(src));\
 	}
 
-#define lasso_list_add_gobject(dest, src) \
+#define lasso_list_add_xml_string(dest, src) \
 	{ \
-		dest = g_list_append(dest, g_object_ref(src)); \
+		lasso_check_type_equality(dest, GList*); \
+		lasso_check_type_equality(src, xmlChar*); \
+		(dest) = g_list_append((dest), g_strdup((char*)src));\
 	}
 
-#define lasso_list_add_new_gobject(dest, src) \
+#define lasso_list_add_gobject(dest, src) \
 	{ \
-		dest = g_list_append(dest, src); \
+		if (G_IS_OBJECT(src)) { \
+			dest = g_list_append(dest, g_object_ref(src)); \
+		} else { \
+			g_critical("Trying to add to a GList* a non GObject pointer dest=%s src=%s", #dest, #src); \
+		} \
 	}
 
-#define lasso_list_add(dest, src) \
+#define lasso_list_add_new_gobject(dest, src) \
 	{ \
-		dest = g_list_append(dest, src); \
+		if (G_IS_OBJECT(src)) { \
+			dest = g_list_append(dest, src); \
+		} else { \
+			g_critical("Trying to add to a GList* a non GObject pointer dest=%s src=%s", #dest, #src); \
+		} \
 	}
 
 /* Freeing */
@@ -99,21 +143,34 @@
 		} \
 	}
 
+#define lasso_release_full2(dest, free_function, type) \
+	{ \
+		lasso_check_type_equality(dest, type); \
+		if (dest) { \
+			free_function(dest); dest = NULL; \
+		} \
+	}
+
 #define lasso_release_gobject(dest) \
-	lasso_release_full(dest, g_object_unref)
+	{ \
+		if (G_IS_OBJECT(dest) || dest == NULL) { \
+			lasso_release_full(dest, g_object_unref); \
+		} else { \
+			g_critical("Trying to unref a non GObject pointer dest=%s", #dest); \
+		} \
+	}
 
 #define lasso_release_string(dest) \
 	lasso_release_full(dest, g_free)
 
 #define lasso_release_list(dest) \
-	lasso_release_full(dest, g_list_free)
+	lasso_release_full2(dest, g_list_free, GList*)
 
 #define lasso_release_list_of_full(dest, free_function) \
 	{ \
 		if (dest) { \
 			g_list_foreach(dest, (GFunc)free_function, NULL); \
-			g_list_free(dest); \
-			dest = NULL; \
+			lasso_release_list(dest); \
 		} \
 	}
 
@@ -127,25 +184,53 @@
 	lasso_release_list_of_full(dest, xmlFreeNode)
 
 #define lasso_release_node(node) \
-	lasso_release_full(node, xmlFreeNode)
+	lasso_release_full2(node, xmlFreeNode, xmlNodePtr)
 
 #define lasso_release_doc(doc) \
-	lasso_release_full(doc, xmlFreeDoc)
+	lasso_release_full2(doc, xmlFreeDoc, xmlDocPtr)
 
 #define lasso_release_xmlchar(dest) \
-	lasso_release_full(dest, xmlFree)
+	lasso_release_full2(dest, xmlFree, xmlChar*)
 
 #define lasso_release_encrypt_context(dest) \
-	lasso_release_full(dest, xmlSecEncCtxDestroy)
+	lasso_release_full2(dest, xmlSecEncCtxDestroy, xmlSecEncCtxPtr)
 
 #define lasso_release_signature_context(dest) \
-	lasso_release_full(dest, xmlSecDSigCtxDestroy)
+	lasso_release_full2(dest, xmlSecDSigCtxDestroy,xmlSecDSigCtxPtr)
 
 #define lasso_release_key_manager(dest) \
-	lasso_release_full(dest, xmlSecKeysMngrDestroy)
+	lasso_release_full2(dest, xmlSecKeysMngrDestroy, xmlSecKeysMngrPtr)
 
 #define lasso_release_output_buffer(dest) \
-	lasso_release_full(dest, xmlOutputBufferClose)
+	lasso_release_full2(dest, xmlOutputBufferClose, xmlOutputBufferPtr)
+
+#define lasso_release_xpath_object(dest) \
+	lasso_release_full2(dest, xmlXPathFreeObject, xmlXPathObjectPtr)
+
+#define lasso_release_xpath_context(dest) \
+	lasso_release_full2(dest, xmlXPathFreeContext, xmlXPathContextPtr)
+
+#define lasso_release_xpath_job(xpathObject, xpathContext, xmlDocument) \
+	lasso_release_xpath_object(xpathObject); \
+	lasso_release_xpath_context(xpathContext); \
+	lasso_release_doc(xmlDocument)
+
+#define lasso_transfer_full(dest, src, kind) \
+	{\
+		lasso_release_##kind((dest)); \
+		lasso_check_type_equality(dest, src); \
+		(dest) = (void*)(src); \
+		(src) = NULL; \
+	}
+
+#define lasso_transfer_xpath_object(dest, src) \
+	lasso_transfer_full(dest, src, xpath_object)
+
+#define lasso_transfer_string(dest, src) \
+	lasso_transfer_full(dest, src, string)
+
+#define lasso_transfer_gobject(dest, src) \
+	lasso_transfer_full(dest, src, gobject)
 
 /* Bad param handling */
 #define lasso_return_val_if_invalid_param(kind, name, val) \