CORE/VOSS/inc/vos_pack_align.h

/*
 * Copyright (c) 2012-2013 The Linux Foundation. All rights reserved.
 *
 * Previously licensed under the ISC license by Qualcomm Atheros, Inc.
 *
 *
 * Permission to use, copy, modify, and/or distribute this software for
 * any purpose with or without fee is hereby granted, provided that the
 * above copyright notice and this permission notice appear in all
 * copies.
 *
 * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL
 * WARRANTIES WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED
 * WARRANTIES OF MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE
 * AUTHOR BE LIABLE FOR ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL
 * DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR
 * PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER
 * TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR
 * PERFORMANCE OF THIS SOFTWARE.
 */

/*
 * This file was originally distributed by Qualcomm Atheros, Inc.
 * under proprietary terms before Copyright ownership was assigned
 * to the Linux Foundation.
 */

#if !defined( __VOS_PACK_ALIGN_H )
#define __VOS_PACK_ALIGN_H

/**=========================================================================
  
  \file  vos_pack_align.h
  
  \brief virtual Operating System Servies (vOS) pack and align primitives
               
   Definitions for platform independent means of packing and aligning
   data structures
  
  
  ========================================================================*/

/*
 
  Place the macro VOS_PACK_START above a structure declaration to pack. We 
  are not going to allow modifying the pack size because pack size cannot be 
  specified in AMSS and GNU. Place the macro VOS_PACK_END below a structure 
  declaration to stop the pack. This requirement is necessitated by Windows
  which need pragma based prolog and epilog.

  Pack-size > 1-byte is not supported since gcc and arm do not support that.
  
  Here are some examples
  
  1. Pack-size 1-byte foo_t across all platforms  
  
  VOS_PACK_START
  typedef VOS_PACK_PRE struct foo_s { ... } VOS_PACK_POST foo_t; 
  VOS_PACK_END
  
  2. 2-byte alignment for foo_t across all platforms
  
  typedef VOS_ALIGN_PRE(2) struct foo_s { ... } VOS_ALIGN_POST(2) foo_t; 

  3. Pack-size 1-byte and 2-byte alignment for foo_t across all platforms

  VOS_PACK_START
  typedef VOS_PACK_PRE VOS_ALIGN_PRE(2) struct foo_s { ... } VOS_ALIGN_POST(2) VOS_PACK_POST foo_t; 
  VOS_PACK_END
  
*/

#if defined __GNUC__

  #define VOS_PACK_START 
  #define VOS_PACK_END 

  #define VOS_PACK_PRE 
  #define VOS_PACK_POST  __attribute__((__packed__))

  #define VOS_ALIGN_PRE(__value)
  #define VOS_ALIGN_POST(__value)  __attribute__((__aligned__(__value)))

#elif defined __arm

  #define VOS_PACK_START 
  #define VOS_PACK_END 

  #define VOS_PACK_PRE  __packed
  #define VOS_PACK_POST

  #define VOS_ALIGN_PRE(__value)  __align(__value)
  #define VOS_ALIGN_POST(__value)

#elif defined _MSC_VER

#define VOS_PACK_START  __pragma(pack(push,1))
#define VOS_PACK_END  __pragma(pack(pop))

  #define VOS_PACK_PRE 
  #define VOS_PACK_POST

  #define VOS_ALIGN_PRE(__value)  __declspec(align(__value))
  #define VOS_ALIGN_POST(__value)

#else

  #error Unsupported compiler!!!

#endif

#endif // __VOSS_PACK_ALIGN_H