rtos: branch compiler_attributes.h for XTOS and Zephyr

Introduce a separate file for Zephyr compiler_attributes.h and
move all Zephyr-specific definitions to this file. This is
a prerequisite to build with CONFIG_SOF_ZEPHYR_STRICT_HEADERS=y.

Link: #9015
Signed-off-by: Kai Vehmanen <kai.vehmanen@linux.intel.com>

xtos/include/sof/compiler_attributes.h

@@ -5,14 +5,8 @@
  * Author: Karol Trzcinski <karolx.trzcinski@linux.intel.com>
  */
 
-#ifdef __ZEPHYR__
-
-#include <zephyr/toolchain.h>
-
-/* Get __sparse_cache and __sparse_force definitions if __CHECKER__ is defined */
-#include <zephyr/debug/sparse.h>
-
-#else
+#ifndef __SOF_COMPILER_ATTRIBUTES_H__
+#define __SOF_COMPILER_ATTRIBUTES_H__
 
 #define __sparse_cache
 #define __sparse_force
@@ -25,8 +19,6 @@
 #define __unused __attribute__((unused))
 #endif
 
-#endif
-
 #ifndef __aligned
 #define __aligned(x) __attribute__((__aligned__(x)))
 #endif
@@ -44,11 +36,9 @@
  */
 #if ((defined(__GNUC__) && (__GNUC__ >= 7)) || \
      (defined(__clang__) && (__clang_major__ >= 10))) && !defined(__CHECKER__)
-
 #define COMPILER_FALLTHROUGH __attribute__((fallthrough))
-
 #else
-
 #define COMPILER_FALLTHROUGH  /* fallthrough */
-
 #endif
+
+#endif /* __SOF_COMPILER_ATTRIBUTES_H__ */

zephyr/include/sof/compiler_attributes.h

@@ -0,0 +1,36 @@
+/* SPDX-License-Identifier: BSD-3-Clause
+ *
+ * Copyright(c) 2024 Intel Corporation.
+ */
+
+#ifndef __SOF_COMPILER_ATTRIBUTES_H__
+#define __SOF_COMPILER_ATTRIBUTES_H__
+
+#include <zephyr/toolchain.h>
+
+/* Get __sparse_cache and __sparse_force definitions if __CHECKER__ is defined */
+#include <zephyr/debug/sparse.h>
+
+#ifndef __aligned
+#define __aligned(x) __attribute__((__aligned__(x)))
+#endif
+
+#ifndef __section
+#define __section(x) __attribute__((section(x)))
+#endif
+
+/* The fallthrough attribute is supported since GCC 7.0
+ * and Clang 10.0.0.
+ *
+ * Note that Clang sets __GNUC__ == 4 so the GCC version
+ * test will not be true here, and must go through
+ * the Clang version test.
+ */
+#if ((defined(__GNUC__) && (__GNUC__ >= 7)) || \
+     (defined(__clang__) && (__clang_major__ >= 10))) && !defined(__CHECKER__)
+#define COMPILER_FALLTHROUGH __attribute__((fallthrough))
+#else
+#define COMPILER_FALLTHROUGH  /* fallthrough */
+#endif
+
+#endif /* __SOF_COMPILER_ATTRIBUTES_H__ */