Simplify test_function_call.

Now it doesn't rely on malloc, which can be tricky to get to work in and
of itself.

2 files changed, 20 insertions, 3 deletions

diff --git a/debug/gdbserver.py b/debug/gdbserver.py
index d7527a2..ede7869 100755
--- a/debug/gdbserver.py
+++ b/debug/gdbserver.py
@@ -224,9 +224,8 @@ class DebugTest(DeleteServer):
     def test_function_call(self):
         self.gdb.b("main:start")
         self.gdb.c()
-        text = "Howdy, Earth!"
-        gdb_length = self.gdb.p('strlen("%s")' % text)
-        self.assertEqual(gdb_length, len(text))
+        self.assertEqual(self.gdb.p('fib(6)'), 8)
+        self.assertEqual(self.gdb.p('fib(7)'), 13)
         self.exit()
 
     def test_change_string(self):
diff --git a/debug/programs/debug.c b/debug/programs/debug.c
index 20b1cdc..3ba51bc 100644
--- a/debug/programs/debug.c
+++ b/debug/programs/debug.c
@@ -5,6 +5,24 @@
 
 unsigned int crc32a(uint8_t *message, unsigned int size);
 
+unsigned int fib(unsigned int n)
+{
+    if (n == 0) {
+        return 0;
+    }
+
+    unsigned int a = 0;
+    unsigned int b = 1;
+
+    for (unsigned int i = 1; i < n; i++) {
+        unsigned int next = a + b;
+        a = b;
+        b = next;
+    }
+
+    return b;
+}
+
 void rot13(char *buf)
 {
     while (*buf) {