[PATCH v1 1/2] kunit: add macro to allow conditionally exposing static symbols to tests

[Rae Moar <rmoar@google.com>]

Create two macros:

VISIBLE_IF_KUNIT - A macro that sets symbols to be static if CONFIG_KUNIT
is not enabled. Otherwise if CONFIG_KUNIT is enabled there is no change
to the symbol definition.

EXPORT_SYMBOL_IF_KUNIT(symbol) - Exports symbol into
EXPORTED_FOR_KUNIT_TESTING namespace only if CONFIG_KUNIT is enabled. Must
use MODULE_IMPORT_NS(EXPORTED_FOR_KUNIT_TESTING) in test file in order to
use symbols.

Signed-off-by: Rae Moar <rmoar@google.com>
---
 include/kunit/visibility.h | 32 ++++++++++++++++++++++++++++++++
 1 file changed, 32 insertions(+)
 create mode 100644 include/kunit/visibility.h

diff --git a/include/kunit/visibility.h b/include/kunit/visibility.h
new file mode 100644
index 000000000000..eb22c9e6b4eb
--- /dev/null
+++ b/include/kunit/visibility.h
@@ -0,0 +1,32 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * KUnit API to allow symbols to be conditionally visible during KUnit
+ * testing
+ *
+ * Copyright (C) 2019, Google LLC.
+ * Author: Brendan Higgins <brendanhiggins@google.com>
+ */
+
+#ifndef _KUNIT_VISIBILITY_H
+#define _KUNIT_VISIBILITY_H
+
+/**
+ * VISIBLE_IF_KUNIT - A macro that sets symbols to be static if CONFIG_KUNIT
+ * is not enabled. Otherwise if CONFIG_KUNIT is enabled there is no change
+ * to the symbol definition.
+ *
+ * EXPORT_SYMBOL_IF_KUNIT(symbol) - Exports symbol into
+ * EXPORTED_FOR_KUNIT_TESTING namespace only if CONFIG_KUNIT is
+ * enabled. Must use MODULE_IMPORT_NS(EXPORTED_FOR_KUNIT_TESTING)
+ * in test file in order to use symbols.
+ */
+#if IS_ENABLED(CONFIG_KUNIT)
+    #define VISIBLE_IF_KUNIT
+    #define EXPORT_SYMBOL_IF_KUNIT(symbol) EXPORT_SYMBOL_NS(symbol, \
+	    EXPORTED_FOR_KUNIT_TESTING)
+#else
+    #define VISIBLE_IF_KUNIT static
+    #define EXPORT_SYMBOL_IF_KUNIT(symbol)
+#endif
+
+#endif /* _KUNIT_VISIBILITY_H */
-- 
2.38.1.273.g43a17bfeac-goog