1 files changed, 56 insertions, 0 deletions
diff --git a/lib/ccan/tally/test/run-total.c b/lib/ccan/tally/test/run-total.c
new file mode 100644
index 00000000000..d7d73e58a5d
--- /dev/null
+++ b/lib/ccan/tally/test/run-total.c
@@ -0,0 +1,56 @@
+#include <ccan/tally/tally.c>
+#include <ccan/tap/tap.h>
+
+int main(void)
+{
+	struct tally *tally;
+	ssize_t total, overflow;
+	ssize_t min, max;
+
+	max = (ssize_t)~(1ULL << (sizeof(max)*CHAR_BIT - 1));
+	min = (ssize_t)(1ULL << (sizeof(max)*CHAR_BIT - 1));
+
+	plan_tests(15);
+
+	/* Simple case. */
+	tally = tally_new(0);
+	tally_add(tally, min);
+	ok1(tally_total(tally, NULL) == min);
+	ok1(tally_total(tally, &overflow) == min);
+	ok1(overflow == -1);
+
+	/* Underflow. */
+	tally_add(tally, min);
+	total = tally_total(tally, &overflow);
+	ok1(overflow == -1);
+	ok1((size_t)total == 0);
+	ok1(tally_total(tally, NULL) == min);
+	free(tally);
+
+	/* Simple case. */
+	tally = tally_new(0);
+	tally_add(tally, max);
+	ok1(tally_total(tally, NULL) == max);
+	ok1(tally_total(tally, &overflow) == max);
+	ok1(overflow == 0);
+
+	/* Overflow into sign bit... */
+	tally_add(tally, max);
+	total = tally_total(tally, &overflow);
+	ok1(overflow == 0);
+	ok1((size_t)total == (size_t)-2);
+	ok1(tally_total(tally, NULL) == max);
+
+	/* Overflow into upper size_t. */
+	tally_add(tally, max);
+	total = tally_total(tally, &overflow);
+	ok1(overflow == 1);
+	if (sizeof(size_t) == 4)
+		ok1((size_t)total == 0x7FFFFFFD);
+	else if (sizeof(size_t) == 8)
+		ok1((size_t)total == 0x7FFFFFFFFFFFFFFDULL);
+	ok1(tally_total(tally, NULL) == max);
+	free(tally);
+
+	return exit_status();
+}