[cfe-dev] Relexing more than one tokens

[Chris Lattner]

On Jul 7, 2009, at 11:54 PM, Abramo Bagnara wrote:
>>> Are you meaning that preprocessing the whole translation unit  
>>> again I'd
>>> get the same SourceLocation opaque ID?
>>
>> Hopefully.  If not, you can do a "deep comparison" along the lines of
>> SourceManager::isBeforeInTranslationUnit.
>
> Instead of preprocessing the whole translation unit, wouldn't be more
> effective to transform Preprocessor::Lex() in a virtual method and
> permit to applications to use a derived class of Preprocessor that  
> have
> a Lex method that after calling Preprocessor::Lex() saves a copy of  
> each
> tokens in the big vector you said above?

Yes, but that would impose an unacceptable performance penalty on the  
normal case.  Also, you can't subclass "Preprocessor".

-Chris