Re: [Boost-bugs] [Boost C++ Libraries] #4282: Please add BOOST_ATTRIBUTE_NORETURN to rethrow_exception()

Subject: Re: [Boost-bugs] [Boost C++ Libraries] #4282: Please add BOOST_ATTRIBUTE_NORETURN to rethrow_exception()
From: Boost C++ Libraries (noreply_at_[hidden])
Date: 2010-06-08 16:06:35

#4282: Please add BOOST_ATTRIBUTE_NORETURN to rethrow_exception()
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 Reporter:  Gevorg Voskanyan <v_gevorg@…>          |       Owner:  emildotchevski
     Type:  Feature Requests                       |      Status:  new           
Milestone:                                         |   Component:  exception     
  Version:  Boost 1.43.0                           |    Severity:  Cosmetic      
 Keywords:                                         |  
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Comment(by Gevorg Voskanyan <v_gevorg@…>):

 No, I didn't make a patch as simple addition of BOOST_ATTRIBUTE_NORETURN
 to rethrow_exception was all was thinking of. That worked for me with
 msvc8 and didn't produce any warnings with /W4. After seeing your comment
 I tried the same with gcc 4.4.0 and indeed it gave me the same "'noreturn'
 function does return" warning. What is most annoying to me is that gcc
 gives such warnings even though there is a #pragma GCC system_header at
 the top of the header file. So I then tried adding a
 throw "convince the compiler this function doesn't return";
 line after p->rethrow(); in rethrow_exception(), which made that warning
 to go away. With both BOOST_ATTRIBUTE_NORETURN and a dummy throw statement
 present, both msvc and gcc happily compile code without warnings they were
 previously complaining about. However I am not sure if that is an
 acceptable solution.
 Or maybe add BOOST_ATTRIBUTE_NORETURN only for msvc as the problem is more
 severe with msvc than with gcc? I don't know.

 To be explicit, here's why I think this is more a problem with msvc than
 gcc. The following code

 {{{
 int f( boost::exception_ptr p )
 {
    boost::rethrow_exception( p );
 }
 }}}

 is rejected by msvc with an error saying that f must return a value,
 whereas gcc merely gives a "control reaches end of non-void function"
 warning.

 Thanks for looking into this,

-- 
Ticket URL: <https://svn.boost.org/trac/boost/ticket/4282#comment:2>
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