[Boost-bugs] [Boost C++ Libraries] #8531: [Coverity] boost/function/function_template.hpp: spurious warnings

Subject: [Boost-bugs] [Boost C++ Libraries] #8531: [Coverity] boost/function/function_template.hpp: spurious warnings
From: Boost C++ Libraries (noreply_at_[hidden])
Date: 2013-05-01 00:41:15

#8531: [Coverity] boost/function/function_template.hpp: spurious warnings
----------------------------------------+-----------------------------------
 Reporter:  Dan Kegel <dank@…>          |       Owner:  dgregor 
     Type:  Bugs                        |      Status:  new     
Milestone:  To Be Determined            |   Component:  function
  Version:  Boost Development Trunk     |    Severity:  Problem 
 Keywords:                              |  
----------------------------------------+-----------------------------------
 This was found in an older release, but is still present in trunk.

 Coverity complains

 {{{
 (1) Event pointless_expression: The expression "false /*
 mpl_::bool_<false>::value */ && false /* mpl_::bool_<false>::value */"
 does not
    accomplish anything because it evaluates to either of its identical
 operands, "false /* mpl_::bool_<false>::value */". Did you intend the
    operands to be different?

 938  if (boost::has_trivial_copy_constructor<Functor>::value &&
 939      boost::has_trivial_destructor<Functor>::value &&
 940
 detail::function::function_allows_small_object_optimization<Functor>::value)
 }}}

 And a similar error near line 973.

 It complains very loudly indeed; every use of assign_to generates this
 warning.
 Until Coverity sprouts a suppression file feature like Valgrind has,
 putting an annotation in the source is the way to make Coverity shut up
 about this.
 The attached patch does that.

 To reproduce (assuming you have a Coverity license, and bjam installed in
 ~/local/bin):

 {{{
 cd ~/boost-trunk/libs/functions/tests
 PATH=/opt/coverity/cov-analysis-linux64-6.5.1/bin:$HOME/local/bin:$PATH
 cov-configure --gcc
 rm -rf covlog
 mkdir -p covlog
 cov-build --dir covlog bjam
 cov-analyze --dir covlog
 cov-format-errors --dir covlog

 }}}

 Then look at covlog/c/output/errors/index.html in a web browser.  If you
 see a bunch of errors like

 CONSTANT_EXPRESSION_RESULT .../boost/function/function_template.hpp

 then you have the problem.  The attached patch makes those warnings go
 away
 (and reduces the number of warnings in this test from 169 to 79).

-- 
Ticket URL: <https://svn.boost.org/trac/boost/ticket/8531>
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