Re: [boost] wave lexed_tokens sample gives an unexpected answer

From: Leo Davis (ldavis_at_[hidden])
Date: 2008-01-16 21:52:09

Hartmut Kaiser wrote:
> Leo, 
> 
>> I built the Wave preprocessing lib out of CVS head today 
>> using GCC 4.2.1 on Linux x86 box (openSUSE 10.3).  I then 
>> built the lexed_tokens sample
>> and ran it on the attached header file.   The unexpected 
>> answer was how
>> the 'defined' keyword was treated.  I expected it to treat it 
>> as T_DEFINED, but it seems to return T_IDENTIFIER as shown by 
>> this output
>> fragment:
>>
>> ...
>> PP_IF            (#370) at foo.h (  4/ 1): >#if<
>> SPACE            (#393) at foo.h (  4/ 4): > <
>> IDENTIFIER       (#381) at foo.h (  4/ 5): >defined<
>> SPACE            (#393) at foo.h (  4/12): > <
>> IDENTIFIER       (#381) at foo.h (  4/13): >BAR<
>> NEWLINE          (#395) at foo.h (  4/16): >\n<
>> ...
> 
> That's (at least a documentaion) bug. The token T_DEFINED get's never
> generated and should be removed from the implementation. 'defined' has a
> special meaning to the preprocessor only and _is_ a identifier for the
> compiler (it's not a keyword). So the bottomline is that the lexed_tokens
> example behaves correctly, but I need to remove the T_DEFINED token-id from
> the implementation to avoid further confusion.

OK.  FYI, *C, A Reference Manual* calls 'defined' an operator in the
context of #if and #elif.

Leo