Re: [Outreachy kernel] [PATCH] Staging: rtl8192u: Simplify if condition.

[Arnd Bergmann <arnd@arndb.de>]

On Tuesday 24 February 2015 22:24:23 Julia Lawall wrote:
> On Tue, 24 Feb 2015, Ksenija Stanojevic wrote:
> 
> > Remove unnecessary TRUE statement. Fields bDynamicTxLowPower and
> > bDynamicTxHighPower are of bool type so such change is correct.
> 
> I'm not sure that the compiler actually enforces that a bool variable is 
> only ever assigned to 0 or 1.  The kernel contains the following in 
> types.h:
> 
> typedef _Bool                   bool;
> 
> The following (non-kernel) C program compiles with gcc with no errors:
> 
> _Bool x;
> 
> int main () {
>   x = 12;
> }
> 
> To be on the safe side, you should look at each place where the field is 
> initialized and check that the value is true or false.  If that is what 
> you have already done, then you should expand on the commit message to 
> make that more apparent.

Actually C enforces this:

_Bool x;
int main()
{ 
        x = 12;
 
        if (x == 1)
                return 1;
        else
                return 2;
}

The compiler ensures that this program returns 1, not 2.

	Arnd