Add facility to track usage of functions.

Use this for plotters so we can see which ones are being used
in any given build.

Build with -DTRACK_USAGE to enable.

1 files changed, 34 insertions, 0 deletions

diff --git a/source/fitz/track-usage.c b/source/fitz/track-usage.c
new file mode 100644
index 00000000..f2d8af49
--- /dev/null
+++ b/source/fitz/track-usage.c
@@ -0,0 +1,34 @@
+#include "mupdf/fitz.h"
+
+#ifdef TRACK_USAGE
+
+static track_usage_data_t *usage_head = NULL;
+
+static void dump_usage(void)
+{
+	track_usage_data_t *u = usage_head;
+
+	while (u)
+	{
+		fprintf(stderr, "USAGE: %s (%s:%d) %d calls\n",
+			u->desc, u->function, u->line, u->count);
+		u = u->next;
+	}
+}
+
+void track_usage(track_usage_data_t *data, const char *function, int line, const char *desc)
+{
+	int c = data->count++;
+	if (c == 0)
+	{
+		data->function = function;
+		data->line = line;
+		data->desc = desc;
+		if (usage_head == NULL)
+			atexit(dump_usage);
+		data->next = usage_head;
+		usage_head = data;
+	}
+}
+
+#endif