[Boost-bugs] [Boost C++ Libraries] #1766: Wrong evaluation of conditional preprocessor directives with predefined macros __FILE__, __LINE__ and __INCLUDE_LEVEL__

Subject: [Boost-bugs] [Boost C++ Libraries] #1766: Wrong evaluation of conditional preprocessor directives with predefined macros __FILE__, __LINE__ and __INCLUDE_LEVEL__
From: Boost C++ Libraries (noreply_at_[hidden])
Date: 2008-04-03 23:05:20

#1766: Wrong evaluation of conditional preprocessor directives  with predefined
macros __FILE__, __LINE__ and __INCLUDE_LEVEL__
-------------------------------------+--------------------------------------
 Reporter:  daniel.wadehn_at_[hidden]     |       Owner:  hkaiser
     Type:  Bugs                     |      Status:  new    
Milestone:  Boost 1.36.0             |   Component:  wave   
  Version:  Boost 1.35.0             |    Severity:  Problem
 Keywords:  wave, predefined makros  |  
-------------------------------------+--------------------------------------
 Checking whether one of the predefined macros {{{__LINE__, __FILE__ and
 __INCLUDE_LEVEL__}}} exists is not possible, wave always returns false
 when one of these macros is checked with the defined() operator or the
 #ifdef directive for example.

 For example this code will trigger the error even though {{{__LINE__}}} is
 defined.
 {{{
 #ifndef __LINE__
 #error "no __LINE__"
 #endif
 }}}

 I had a look at the source and think it can be fixed in cpp_macromap.hpp:
 There are three overloads for macromap<>::is_defined(), but only one
 checks for the special case of those three predefined macros.
 If the other overloads call the working one, the problem seems gone.

 However, i have no experience with the wave source and just started having
 a look at it today, thats why i have no idea if there aren't any side-
 effects with this 'fix' and I'm looking for an official fix or a reply on
 this case.
 I have attached my .patch though.

-- 
Ticket URL: <http://svn.boost.org/trac/boost/ticket/1766>
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