memory alignment

[Ahn Jung Hoon]

Hello.

During anylizing the source code,

I found the difficult code.. ( u8:0; u8:8; u8:0; )

I don't understand this code..

and I want to know that what i have to read to understand "momory alignment"..

/*
** =========================================================================
** Memory alignment tools
** =========================================================================
*/

#define MC_PCC_FILL_STRUCT1 u8:0; u8:8; u8:0; ???
#define MC_PCC_FILL_STRUCT2 u8:0; u8:8; u8:8; u8:0; ???
#define MC_PCC_FILL_STRUCT3 u8:0; u8:8; u8:8; u8:8; u8:0; ???

typedef struct aaa
{
t_MsgHeader MsgHeader;
u8 msg_param[MAX_LENGTH_OF_L3_MSG];
MC_PCC_FILL_STRUCT1
}bbb;

 

[Jack Klein]

Hello.

During anylizing the source code,

I found the difficult code.. ( u8:0; u8:8; u8:0; )

I don't understand this code..

and I want to know that what i have to read to understand "momory alignment"..

/*
** =========================================================================
** Memory alignment tools
** =========================================================================
*/

#define MC_PCC_FILL_STRUCT1 u8:0; u8:8; u8:0; ???
#define MC_PCC_FILL_STRUCT2 u8:0; u8:8; u8:8; u8:0; ???
#define MC_PCC_FILL_STRUCT3 u8:0; u8:8; u8:8; u8:8; u8:0; ???

typedef struct aaa
{
t_MsgHeader MsgHeader;
u8 msg_param[MAX_LENGTH_OF_L3_MSG];
MC_PCC_FILL_STRUCT1
}bbb;

This code was written by one of two programmers:

1. One with a very specific low-level problem that had to be dealt
with this way, and was very familiar with the characteristics of the
compiler and the underlying hardware.

2. One who was not very smart, at least not as smart as he/she
thought he/she was.

In either case it is extremely non-portable.

As to what :0 does, look up bit-fields in any competent book on C.

--
Jack Klein
Home: http://JK-Technology.Com
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