Compiling glibc-2.3.2 with gcc-3.4 yields "string2.h:80: warning: `packed' attribute ignored"

[Jim Wilson]

Dan Kegel wrote:
> # define __STRING2_COPY_TYPE(N) \
>   typedef struct { unsigned char __arr[N]; 
> }                                  \
>     __STRING2_COPY_ARR##N __attribute__ ((packed))

This looks like a glibc problem.  The syntax for typedef is roughly
	typedef <type> <name>;
glibc put the attribute at the end, which means it is after <name>, but 
attaching a packed attribute to a name is useless, and hence it is being 
ignored.  If you want the packed attribute to do something, it needs to 
be attached to <type> intead of <name>.

It looks like the only change here is that gcc used to silently ignore 
the misplaced attribute, and is now warning about it which is an 
improvement.  Trying gcc-3.2, I get no warning, and the struct is not 
packed either.
-- 
Jim Wilson, GNU Tools Support, http://www.SpecifixInc.com