tests/float: automated test and added pexpect script

tests/float/Makefile

@@ -3,4 +3,12 @@ include ../Makefile.tests_common
 
 DISABLE_MODULE += auto_init
 
+# for native we can go do a couple of more operations in reasonable time...
+ifneq (,$(filter native,$(BOARD)))
+  CFLAGS += -DTEST_ITER=100000000
+endif
+
 include $(RIOTBASE)/Makefile.include
+
+test:
+	tests/01-run.py

tests/float/README.md

@@ -1,10 +1,14 @@
 Expected result
 ===============
-This application should infinitely print '-' characters. If it prints only a single '+' characters the test must be considered as failed.
+This application increases a non-even floating point number in steps of 0.1
+starting from from 1234567.0 / 1024.0 ~= 1205.631835938. For each step it checks
+if the sum minus its 'floored' values is less than 1.0 (which it should always be
+by definition of `floor`).
 
 Background
 ==========
-This test was introduced due to an error for floating point handling in an older newlib version.
+This test was introduced due to an error for floating point handling in an older
+newlib version.
 
 The idea for this test is taken from:
 http://sourceware.org/ml/newlib/2010/msg00149.html

tests/float/main.c

@@ -1,5 +1,6 @@
 /*
  * Copyright (C) 2013 INRIA
+ *               2017 Freie Universität Berlin
  *
  * This file is subject to the terms and conditions of the GNU Lesser
  * General Public License v2.1. See the file LICENSE in the top level
@@ -7,13 +8,14 @@
  */
 
 /**
- * @ingroup tests
+ * @ingroup     tests
  * @{
  *
  * @file
- * @brief Float test application
+ * @brief       Float test application
  *
  * @author      Oliver Hahm <oliver.hahm@inria.fr>
+ * @author      Hauke Petersen <hauke.petersen@fu-berlin.de>
  *
  * @}
  */
@@ -23,19 +25,29 @@
 
 #include "board.h"
 
+/* as default we run the test 100k times */
+#ifndef TEST_ITER
+#define TEST_ITER           (100000UL)
+#endif
+
+#define STEP                (0.1)
+
 int main(void)
 {
     double x = 1234567.0 / 1024.0;
 
-    while (1) {
-        x += 0.1;
-        double z = x - floor(x);
+    puts("Testing floating point arithmetics...\n");
 
-        if (z >= 1) {
-            putchar('+');
-        }
-        else {
-            putchar('-');
+    for (unsigned long i = 0; i < TEST_ITER; i++) {
+        x += STEP;
+        double z = (x - floor(x));
+        if (z >= 1.0) {
+            puts("[FAILED]");
+            return 1;
         }
     }
+
+    puts("[SUCCESS]");
+
+    return 0;
 }

tests/float/tests/01-run.py

@@ -0,0 +1,20 @@
+#!/usr/bin/env python3
+
+# Copyright (C) 2017 Freie Universität Berlin
+#
+# This file is subject to the terms and conditions of the GNU Lesser
+# General Public License v2.1. See the file LICENSE in the top level
+# directory for more details.
+
+import os
+import sys
+
+sys.path.append(os.path.join(os.environ['RIOTBASE'], 'dist/tools/testrunner'))
+import testrunner
+
+def testfunc(child):
+    child.expect_exact("Testing floating point arithmetics...")
+    child.expect_exact("[SUCCESS]")
+
+if __name__ == "__main__":
+    sys.exit(testrunner.run(testfunc))