X-Git-Url: https://git.stderr.nl/gitweb?a=blobdiff_plain;f=libchimara%2Fmagic.c;fp=libchimara%2Fmagic.c;h=a385b9636bc185655c1dad10b6cee7061ddd7546;hb=0b85f1dd5993e2ed111ec2ba13bbbb4ebda06ada;hp=0000000000000000000000000000000000000000;hpb=08f8444e2ae5480eea1cf7e2c1e2eb57f46152db;p=rodin%2Fchimara.git

diff --git a/libchimara/magic.c b/libchimara/magic.c
new file mode 100644
index 0000000..a385b96
--- /dev/null
+++ b/libchimara/magic.c
@@ -0,0 +1,56 @@
+#include <gtk/gtk.h>
+#include "glk.h"
+#include "magic.h"
+
+/* The "magic" mechanism was stolen from Evin Robertson's GtkGlk. */
+
+static gchar *
+magic_to_string(glui32 magic)
+{
+	switch(magic)
+	{
+		case MAGIC_WINDOW:
+			return "winid_t";
+		case MAGIC_STREAM:
+			return "strid_t";
+		case MAGIC_FILEREF:
+			return "frefid_t";
+		case MAGIC_SCHANNEL:
+			return "schanid_t";
+		default:
+			g_return_val_if_reached("unknown");
+	}
+}
+
+/* Internal function: check the object's magic number to make sure it is the
+ right type, and not freed. */
+gboolean
+magic_is_valid_or_null(const glui32 goodmagic, const glui32 realmagic, const gchar *function)
+{
+	if(realmagic != MAGIC_NULL)
+	{
+		if(realmagic != goodmagic)
+		{
+			if(realmagic == MAGIC_FREE)
+				g_critical("%s: Using a freed object", function);
+			else
+				g_critical( "%s: %s object not a %s", function, magic_to_string(realmagic), magic_to_string(goodmagic) );
+			return FALSE;
+		}
+	}
+	return TRUE;
+}
+ 
+
+/* Internal function: check the object's magic number to make sure it is
+ not NULL, the right type, and not freed. */
+gboolean 
+magic_is_valid(const void *obj, const glui32 goodmagic, const glui32 realmagic, const gchar *function)
+{
+	if(obj == NULL)
+	{
+		g_critical( "%s: NULL %s pointer", function, magic_to_string(goodmagic) );
+		return FALSE;
+	}
+	return magic_is_valid_or_null(goodmagic, realmagic, function);
+}