tests: Add test app for sys/architecture

tests/sys_architecture/Makefile

@@ -0,0 +1,16 @@
+BOARD ?= samr21-xpro
+include ../Makefile.tests_common
+
+include $(RIOTBASE)/Makefile.include
+
+ifneq (,$(filter arch_32bit,$(FEATURES_USED)))
+  CFLAGS += -DCORRECT_WORD_BITS=32
+endif
+
+ifneq (,$(filter arch_16bit,$(FEATURES_USED)))
+  CFLAGS += -DCORRECT_WORD_BITS=16
+endif
+
+ifneq (,$(filter arch_8bit,$(FEATURES_USED)))
+  CFLAGS += -DCORRECT_WORD_BITS=8
+endif

tests/sys_architecture/main.c

@@ -0,0 +1,96 @@
+/*
+ * Copyright (C) 2020 Otto-von-Guericke-Universität Magdeburg
+ *
+ * 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.
+ */
+
+/**
+ * @ingroup tests
+ * @{
+ *
+ * @file
+ * @brief       Test application for sys/architecture
+ *
+ * @author      Marian Buschsieweke <marian.buschsieweke@ovgu.de>
+ *
+ * @}
+ */
+
+#include <stdint.h>
+#include <stdio.h>
+
+#include "assert.h"
+#include "architecture.h"
+
+/* On all but 8bit architectures, at least one of the following should be
+ * misaligned */
+static char unaligned_a[1];
+static char unaligned_b[1];
+
+/* If WORD_ALIGNED is not working correctly, at least one of the following
+ * should be misaligned (except for 8bit architectures, on which alignment
+ * doesn't matter). */
+static char WORD_ALIGNED aligned_a[1];
+static char WORD_ALIGNED aligned_b[1];
+
+static inline unsigned get_misalignemnt(const char *ptr)
+{
+    /* word size is always a power of two, so we can speed up the modulo */
+    return (uintptr_t)ptr & (ARCHITECTURE_WORD_BYTES - 1);
+}
+
+int main(void)
+{
+    /* Most can be evaluated at compile time, so we just do this :-)
+     * Using multiple static asserts in a single function doesn't play nicely
+     * with the non-C11 fallback implementation of static_assert, so we just
+     * use a single use statement.
+     */
+    static_assert(
+        (ARCHITECTURE_WORD_BITS == CORRECT_WORD_BITS) &&
+        (ARCHITECTURE_WORD_BYTES == CORRECT_WORD_BITS / 8) &&
+        (sizeof(uword_t) == ARCHITECTURE_WORD_BYTES) &&
+        (sizeof(sword_t) == ARCHITECTURE_WORD_BYTES),
+        "word size details are incorrect"
+    );
+
+    printf("One word is %u bits or %u bytes in size\n",
+           ARCHITECTURE_WORD_BITS, ARCHITECTURE_WORD_BYTES);
+
+    int failed = 0;
+
+    if (ARCHITECTURE_WORD_BYTES == 1) {
+        puts("Skipping test for WORD_ALIGNED; every alignment is fine on 8bit "
+             "architectures.");
+    }
+    else {
+        printf("%s", "Verifying test works: ");
+        if (get_misalignemnt(unaligned_a) || get_misalignemnt(unaligned_b)) {
+            puts("OK");
+        }
+        else {
+            puts("FAILED");
+            failed = 1;
+        }
+
+        printf("%s", "Verifying WORD_ALIGNED works: ");
+        if (get_misalignemnt(aligned_a) || get_misalignemnt(aligned_b)) {
+            puts("FAILED");
+            failed = 1;
+        }
+        else {
+            puts("OK");
+        }
+    }
+
+    if (failed) {
+        puts("TEST FAILED");
+    }
+    else {
+        puts("TEST SUCCEEDED");
+    }
+
+    return 0;
+}

tests/sys_architecture/tests/01-run.py

@@ -0,0 +1,21 @@
+#!/usr/bin/env python3
+
+#  Copyright (C) 2020 Otto-von-Guericke-Universität Magdeburg
+#
+# 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.
+
+# @author      Marian Buschsieweke <marian.buschsieweke@ovgu.de>
+
+import sys
+from testrunner import run
+
+
+def testfunc(child):
+    # Try to wait for the shell
+    child.expect_exact("TEST SUCCEEDED")
+
+
+if __name__ == "__main__":
+    sys.exit(run(testfunc))