[BusyBox] #define -> static const int (last call)

[Vladimir N. Oleynik]

Mark Whitley wrote:
> 
> On Static Buffer Elimination
> ----------------------------
> 
> First, some background to put this discussion in context: Static
> buffers look
> like this in code:
> 
>         /* in a .c file outside any functions */
>         static char *buffer[BUFSIZ]; /* happily used by any function
> in this file,
>                                         but ick! big! */
> 
>         static char *pbuffer
>         ...
>         other_func()
>         {
>                 strcpy(pbuffer, lotsa_chars); /* happily uses global
> *pbuffer */
>         ...
>         foo_main()
>         {
>                 char *buffer[BUFSIZ]; /* declared locally, on stack */
>                 pbuffer = buffer;     /* but available globally */
>         ...
> 

BAD!
System discarding this BSS memory after end usage.
Additional size. Not gain!! Stack is very limited resource.


> $ size busybox-orig
>    text    data     bss     dec     hex filename
>  237501   29660   65884  333045   514f5 busybox-orig
> $ size busybox-const
>    text    data     bss     dec     hex filename
>  238157   29692   39964  307813   4b265 busybox-const
>                   ^^^^^
>                    yay!

^^^^^^^^^^^^^^ - is interessing. BSS size not interessing.
 

--w
vodz