core/xfa: disable asan on llvm

core/lib/include/compiler_hints.h

@@ -68,6 +68,20 @@ extern "C" {
 #endif
 #endif
 
+/**
+ * @def       NO_SANITIZE_ARRAY
+ * @brief     Tell the compiler that this array should be ignored during sanitizing.
+ * @details   In special cases, e.g. XFA, the address sanitizer might interfere
+ *            in a way that breaks the application. Use this macro to disable
+ *            address sanitizing for a given variable. Currently only utilised
+ *            by llvm.
+ */
+#if defined(__llvm__) || defined(__clang__)
+#define NO_SANITIZE_ARRAY __attribute__((no_sanitize("address")))
+#else
+#define NO_SANITIZE_ARRAY
+#endif
+
 /**
  * @def       UNREACHABLE()
  * @brief     Tell the compiler that this line of code cannot be reached.

core/lib/include/xfa.h

@@ -26,6 +26,7 @@
 #define XFA_H
 
 #include <inttypes.h>
+#include "compiler_hints.h"
 
 /*
  * Unfortunately, current gcc trips over accessing XFA's because of their
@@ -42,16 +43,18 @@ _Pragma("GCC diagnostic ignored \"-Warray-bounds\"")
  *
  * @internal
  */
-#define _XFA(name, prio) __attribute__((used, section(".xfa." #name "." #prio)))
+#define _XFA(name, prio) \
+    NO_SANITIZE_ARRAY \
+    __attribute__((used, section(".xfa." #name "." #prio)))
 
 /**
  * @brief helper macro for other XFA_* macros
  *
  * @internal
  */
-#define _XFA_CONST(name, \
-                   prio) __attribute__((used, \
-                                        section(".roxfa." #name "." #prio)))
+#define _XFA_CONST(name, prio) \
+    NO_SANITIZE_ARRAY \
+    __attribute__((used, section(".roxfa." #name "." #prio)))
 
 /**
  * @brief Define a read-only cross-file array