Add alignof() macro.

This macro returns the alignment in memory of a generic data type.

git-svn-id: https://src.develer.com/svnoss/bertos/trunk@3224 38d2e660-2303-0410-9eaa-f027e97ec537

diff --git a/bertos/cfg/compiler.h b/bertos/cfg/compiler.h
index 87cdd9425a4159617880e40e2a803d929089a397..5cacf1dca66fe20041b8e2fa0aa5133b66aad3d0 100644 (file)
--- a/bertos/cfg/compiler.h
+++ b/bertos/cfg/compiler.h
@@ -490,6 +490,16 @@ typedef unsigned char page_t;    /**< Type for banked memory pages. */
         */
        #define countof(a)  (sizeof(a) / sizeof(*(a)))
 #endif
+#ifndef alignof
+       /**
+        * Return the alignment in memory of a generic data type.
+        *
+        * \note We need to worry about alignment when allocating memory that
+        * will be used later by unknown objects (e.g., malloc()) or, more
+        * generally, whenever creating generic container types.
+        */
+       #define alignof(type) offsetof(struct { char c; type member; }, member)
+#endif
 
 /**
  * Cast a member of a structure out to the containing structure.