[Boost-bugs] [Boost C++ Libraries] #6365: Compiler warnings when running static code analysis after build on MSVC 10

Subject: [Boost-bugs] [Boost C++ Libraries] #6365: Compiler warnings when running static code analysis after build on MSVC 10
From: Boost C++ Libraries (noreply_at_[hidden])
Date: 2012-01-07 14:36:50

#6365: Compiler warnings when running static code analysis after build on MSVC 10
---------------------------------------+------------------------------------
 Reporter:  seppe.de.clercq@…          |       Owner:  emildotchevski
     Type:  Bugs                       |      Status:  new           
Milestone:  To Be Determined           |   Component:  exception     
  Version:  Boost 1.48.0               |    Severity:  Cosmetic      
 Keywords:                             |  
---------------------------------------+------------------------------------
 As the title says I'm getting several compiler warnings when running
 static code analysis in Visual Studio 10 (attached the list to the
 ticket).

 The reported warnings are harmless (are only triggered by the static
 analyzer and not when compiling with warning level 4), but could you fix
 them if you have the time?

 I'm getting two type of warnings.

 == Warning type 1 ==

 warning C6246: Local declaration of 'l' hides declaration of the same name
 in outer scope. For additional information, see previous declaration at
 line '131' of
 'c:\users\seppe\boost_1_48_0\boost\exception\diagnostic_information.hpp':
 Lines: 131
 c:\users\seppe\boost_1_48_0\boost\exception\diagnostic_information.hpp
 140

 warning C6246: Local declaration of 'fn' hides declaration of the same
 name in outer scope. For additional information, see previous declaration
 at line '132' of
 'c:\users\seppe\boost_1_48_0\boost\exception\diagnostic_information.hpp':
 Lines: 132
 c:\users\seppe\boost_1_48_0\boost\exception\diagnostic_information.hpp
 144

 and the affected code:

 {{{
 130: char const * const * f=get_error_info<throw_file>(*be);
 131: int const * l=get_error_info<throw_line>(*be);
 132: char const * const * fn=get_error_info<throw_function>(*be);
 133: if( !f && !l && !fn )
 134:    tmp << "Throw location unknown (consider using
 BOOST_THROW_EXCEPTION)\n";
 135: else
 136: {
 137:    if( f )
 138:    {
 139:       tmp << *f;
 140:       if( int const * l=get_error_info<throw_line>(*be) )
 141:          tmp << '(' << *l << "): ";
 142:    }
 143:    tmp << "Throw in function ";
 144:    if( char const * const * fn=get_error_info<throw_function>(*be) )
 145:       tmp << *fn;
 146:    else
 147:       tmp << "(unknown)";
 148:    tmp << '\n';
 149: }
 }}}

 Both warnings can be fixed by:

     - line 140: replacing if( int const *
 l=get_error_info<throw_line>(*be) ) with if( l )
     - line 144: replacing if( char const * const *
 fn=get_error_info<throw_function>(*be) ) with if( fn )

 == Warning type 2 ==

 Only displaying the first warning.

 warning C6246: Local declaration of 'e' hides declaration of the same name
 in outer scope. For additional information, see previous declaration at
 line '300' of
 'c:\users\seppe\boost_1_48_0\boost\exception\detail\exception_ptr.hpp':
 Lines: 300
 c:\users\seppe\boost_1_48_0\boost\exception\detail\exception_ptr.hpp
 332

 and the affected code:


 {{{

 296: inline
 297: exception_ptr
 298: current_exception_impl()
 299:     {
 300:     exception_detail::clone_base const * e=0;

 <<snip>>

 328:         try
 329:             {
 330:             throw;
 331:             }
 332:         catch(
 333:         exception_detail::clone_base & e )
 334:             {
 335:             return
 exception_ptr(shared_ptr<exception_detail::clone_base const>(e.clone()));
 336:             }

 ...

 }}}

 Well this is more of a false positive of the static analyzer, but can be
 avoided by changing the variable name of the caught exception.

 '''Remark''': A warning is generated for each caught exception in the
 method (see attached list).

-- 
Ticket URL: <https://svn.boost.org/trac/boost/ticket/6365>
Boost C++ Libraries <http://www.boost.org/>
Boost provides free peer-reviewed portable C++ source libraries.