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

[Bill Wendling]

On Jan 2, 2009, at 3:11 PM, Bill Wendling wrote:

> 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.
>
Never mind that comment. I see that "ptr" is being assigned to a real  
buffer.

-bw