Bug#299188: gcc: -ffreestanding and builtins don't work as expected

[Thiemo Seufer <ths@networkno.de>]

Adrian Bunk wrote:
[snip]
> #define sprintf __builtin_sprintf
> 
> int main()
> {
>   char str[] = "abc";
>   char buf[10];
> 
>   sprintf(buf,"%s",str);
> 
>   return 0;
> }
[snip]
>         call    strcpy
[snip]
> As far as I understand the documentation, the call to strcpy
> shouldn't be emitted since this function is not required in a
> freestanding environment.
> 
> gcc-3.3 and gcc-4.0 behave similar.
> 
> I'm not sure whether this is expected, but if it is, the documentation
> should be updated.

You explicitly requested the __builtin_sprintf implementation, which is
allowed to decay to strcpy, and overrode the -ffreestanding in this
case. AFAICS the documentation is correct (but not that explicit for
that cornercase).


Thiemo