Re: Subtleties of __attribute__((packed))

[Jan Blunck <jblunck@suse.de>]

On Wed, Dec 06, Phil Endecott wrote:

> 
> To see a difference with your example structs you need to compare these two:
> 
> struct wibble1 {
>   char c;
>   struct bar1 b1;
> };
> 
> struct wibble2 {
>   char c;
>   struct bar2 b2;
> };
> 
> struct wibble1 w1 = { 1, { 2, {3,4,5} } };
> struct wibble2 w2 = { 1, { 2, {3,4,5} } };
> 
> Can you try that with your compilers?  I get:
> 

As I expected, I get:

	.file	"packed2a.c"
.globl w1
.data
	.align	2
	.type	w1, @object
	.size	w1, 14
w1:
	.byte	1
	.byte	2
	.4byte	3
	.byte	4
	.zero	3
	.4byte	5
.globl w2
	.align	2
	.type	w2, @object
	.size	w2, 14
w2:
	.byte	1
	.byte	2
	.4byte	3
	.byte	4
	.zero	3
	.4byte	5
	.ident	"GCC: (GNU) 4.1.2 20060531 (prerelease) (SUSE Linux)"
	.section	.note.GNU-stack,"",@progbits