On Wed, Jul 24, 2013 at 2:53 AM, Florian Weimer <fweimer@xxxxxxxxxx> wrote:
> On 07/12/2013 06:16 PM, Ian Lance Taylor wrote:
>
>>> for(int i = 0;; ({break;}))
>
>
>> But probably you wanted to know whether it is a bug in LLVM or in GCC.
>> It's a bug in LLVM. You can't use break in a statement expression to
>> break out of a loop that is not in the statement expression.
>> Statement expressions are their own thing; they don't inherit the
>> surrounding context, except that using a goto statement to a label
>> outside the statement expression is permitted.
>
>
> This is not what's implemented in GCC 4.8. This code compiles (both as C
> and C++):
>
> int
> f()
> {
> int x = 1;
> while (1) {
> x = ({break; 5;});
> }
> return x;
> }
>
> The discrepancy between GCC and Clang is whether the expressions in the for
> statement header are considered nested within the loop. I'm not sure if
> these aspects of statement expressions can be considered fully fleshed out.
Wow, OK, that surprises me. I now think that's a bug in GCC, but it
may be hard to change it now.
Ian
