[llvm-commits] [llvm] r61576 - /llvm/trunk/unittests/ADT/ImmutableSetTest.cpp

[Bill Wendling]

On Jan 2, 2009, at 6:37 AM, Misha Brukman wrote:

> +static char *ptr; // tmp var
> +struct MyIter {
> +  int counter;
> +  MyIter() : counter(0) {}
> +  void operator()(char c) {
> +    *ptr++ = c;
> +    ++counter;
> +  }
> +};
>
> Global state is frowned upon -- if you don't properly clear it  
> between tests, strange bugs will occur, and they will depend on the  
> order of the test execution (which aren't guaranteed to execute in  
> any particular order).  This will lead to strange Heisenbugs.
>
> Instead, you can make another Fixture class, and make this state a  
> part of that class.  If you set up that state, you'll know you're  
> always getting a clean beginning state, and you'll have nothing to  
> worry about.
>
Also, the "*ptr++" is writing over memory that's not allocated. I'm  
going to get rid of the "++" in there. I think that that's causing  
some test failures. But the general "global state" needs to be  
addressed.

-bw