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Re: [lwip-users] a question about alignment
From: |
stephen |
Subject: |
Re: [lwip-users] a question about alignment |
Date: |
Wed, 3 Nov 2004 17:16:56 +0800 |
Jack:
These macros are used to pack ethernet/ip/tcp header structure.
You can see "struct ip_hdr" in "ip.h"
But if you want to declare your own structure, just forget these macros.
----- Original Message -----
From: "jack W" <address@hidden>
To: "lwip-users" <address@hidden>
Sent: Wednesday, November 03, 2004 3:42 PM
Subject: [lwip-users] a question about alignment
> hi everyone
>
>
> i am reading the lwip source codes , i happend a question about structure
alignments .
>
> in the codes it says : there are four macros #PACK_STRUCT_BEGIN
#PACK_STRUCT_FIELD
> #PACK_STRUCT_STRUCT and #PACK_STRUCT_END
>
> if i define a structure named xyz following :
>
> #PACK_STRUCT_BEGIN
> struct xyz{
> int xxx
>
> }
> #PACK_STRUCT_END
>
> IF i should write the "#PACK_STRUCT_FIELD" in the front of variable "int
xxx" or not ?
>
>
>
>
>
>
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