r221804 - Use the return of readBytes to find out if we are at the end of the stream.

[Rafael Avila de Espindola]

Would it reproduce with opt and an empty file?

Sent from my iPhone

> On Nov 12, 2014, at 18:54, Jordan Rose <jordan_rose at apple.com> wrote:
> 
> 
>> On Nov 12, 2014, at 15:38, Rafael Avila de Espindola <rafael.espindola at gmail.com> wrote:
>> 
>> 
>> 
>> Sent from my iPhone
>> 
>>> On Nov 12, 2014, at 18:22, Jordan Rose <jordan_rose at apple.com> wrote:
>>> 
>>> Looks like it's just this:
>>> 
>>> diff --git a/include/llvm/Bitcode/BitstreamReader.h b/include/llvm/Bitcode/BitstreamReader.h
>>> index 6b9c858..41e50e1 100644
>>> --- a/include/llvm/Bitcode/BitstreamReader.h
>>> +++ b/include/llvm/Bitcode/BitstreamReader.h
>>> @@ -227,7 +227,7 @@ public:
>>> bool AtEndOfStream() {
>>>   if (BitsInCurWord != 0)
>>>     return false;
>>> -    if (Size == NextChar)
>>> +    if (Size != 0 && Size == NextChar)
>>>     return true;
>>>   fillCurWord();
>>>   return BitsInCurWord == 0;
>>> 
>>> i.e. you forgot about the fact that we /start/ with both Size and NextChar equal to 0. Does this look like the right fix to you?
>> 
>> 
>> Oh, so a call at the very start would fail. LGTM
> 
> Yup, I don't have a test case in LLVM's code, but Swift is checking explicitly for an empty file. Took me a while to track that down.
> 
> Thanks, I'll commit.
> Jordan
>