On Mon, Sep 05, 2016 at 12:35:13PM +0200, Bernd Schmidt wrote:
> On 09/02/2016 05:13 PM, Marek Polacek wrote:
> > diff --git gcc/doc/invoke.texi gcc/doc/invoke.texi
> > index 87da1f1..38d55d4 100644
> > --- gcc/doc/invoke.texi
> > +++ gcc/doc/invoke.texi
> > @@ -5437,8 +5437,8 @@ if (a < 0 && a < 0) @{ @dots{} @}
> > @opindex Wlogical-not-parentheses
> > @opindex Wno-logical-not-parentheses
> > Warn about logical not used on the left hand side operand of a comparison.
> > -This option does not warn if the RHS operand is of a boolean type. Its
> > -purpose is to detect suspicious code like the following:
> > +This option does not warn if the right operand is considered to be a
> > Boolean
> > +expression. Its purpose is to detect suspicious code like the following:
>
> I think "Boolean" shouldn't be capitalized. The patch looks ok to me
> otherwise.
No strong opinions, but looking at
https://en.wikipedia.org/wiki/Boolean_expression
I see that it's capitalized there, so I think let's keep "Boolean".
> > + r += !a == (b | c);
>
> I do wonder whether we should give a different warning for this though. I
> personally prefer code involving bools to use || to show it's a logical
> operation. Bit-wise may indicate mistakes where the programmer thought he
> was operating on integers.
Yea. I'd swear that I've seen an RFE somewhere for this in the GCC BZ,
I mean to warn for bool1 * bool2, bool1 / bool2, etc. Though I'm not sure
if warning for bool1 | bool2 would be desirable.
Thanks, I think I'll commit this later today.
Marek
