[lwip-devel] Re: [patch #6414] Avoid compiler errors/warnings with mem_size_t if MEM_LIBC_MALLOC

[Iordan Neshev]

Jonathan Larmour wrote:
> URL:
>   <http://savannah.nongnu.org/patch/?6414>
>
>                  Summary: Avoid compiler errors/warnings with mem_size_t if
> MEM_LIBC_MALLOC
>   ...
>
>     _______________________________________________________
>
> Details:
>
> As per the discussion "Possible mistake in mem.h" here:
> http://lists.gnu.org/archive/html/lwip-devel/2008-01/threads.html
>
> here is an untested patch.
>
> Can someone (Iordan?) please verify it resolves the issue.
>
> Note that I had to remove the MEM_SIZE_F format string, since I could not do
> anything sane with it if mem_size_t is size_t. The size of size_t is unknown
> for the purposes of determining the format specifier, and getting the wrong
> size could screw up the stack on some architectures. I doubt the %z specifier
> (the offical ISO C 99 way) is portable enough to rely on. We could a SIZE_T_F
> requirement on ports, but that seems arduous given the only use is from a
> debug statistics display function, so I've just cast to 32.
>
> Kieran, please let me know if this is ok for check-in prior to 1.3.0 or not
> (once tested).
>
> Jifl
>
>
>
>   

Hello
The patch solves the problem :)
but rises other 3 warnings that are trivial, and IMHO can be fixed right 
now without discussion.

There are 3 lines where the return value of mem_malloc() (which is 
void*) is not casted
to the target types. Someone just forgot this. There is the list:


pbuf.c, line 210:
p = (struct pbuf*) mem_malloc(LWIP_MEM_ALIGN_SIZE(SIZEOF_STRUCT_PBUF + 
offset) + LWIP_MEM_ALIGN_SIZE(length));// casted!!!

ppp.c, line 401:
outpacket_buf[i] = (u_char *) mem_malloc(PPP_MRU+PPP_HDRLEN); // casted!!!

httpd.c, line 215 (httpserver_raw example)
hs = (struct http_state *) mem_malloc(sizeof(struct http_state)); // 
casted!!!

Searching for mem_malloc I noticed some other places where the return value
should also be casted, but they are ignored because of the #ifdef-s.

Greetings
Iordan Neshev