Re: [Boost-users] Compare boost::system::error_category

Subject: Re: [Boost-users] Compare boost::system::error_category
From: Thomas Markwalder (tmark_at_[hidden])
Date: 2017-03-27 13:18:03

This is the same issue I reported here:

https://svn.boost.org/trac/boost/ticket/11989

and passed it on to GCC as well:

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=69789

On 3/24/17 4:34 PM, Christopher Pisz via Boost-users wrote:
> (MSVS Specific)
>
> So I've edited all the target files for the public Nuget packages for all
> the boost libraries I am using to look like:
>
> <?xml version="1.0" encoding="utf-8"?>
> <Project ToolVersion="4.0"
> xmlns="http://schemas.microsoft.com/developer/msbuild/2003">
>   <ItemDefinitionGroup Condition="'$(Platform)'=='Win32'">
> 	<ClCompile>
>      
> <PreprocessorDefinitions>BOOST_ALL_DYN_LINK;%(PreprocessorDefinitions)</PreprocessorDefinitions>
>     </ClCompile>
>     <Link>
>      
> <AdditionalLibraryDirectories>$(MSBuildThisFileDirectory)..\..\lib\native\address-model-32\lib;%(AdditionalLibraryDirectories)</AdditionalLibraryDirectories>
>     </Link>
>   </ItemDefinitionGroup>
>   <ItemDefinitionGroup Condition="'$(Platform)'=='x64'">
> 	<ClCompile>
>      
> <PreprocessorDefinitions>BOOST_ALL_DYN_LINK;%(PreprocessorDefinitions)</PreprocessorDefinitions>
>     </ClCompile>
>     <Link>
>      
> <AdditionalLibraryDirectories>$(MSBuildThisFileDirectory)..\..\lib\native\address-model-64\lib;%(AdditionalLibraryDirectories)</AdditionalLibraryDirectories>
>     </Link>
>   </ItemDefinitionGroup>
>   <ItemGroup />
>   
>   <Target Name="CopyBoostAtomicDll" BeforeTargets="PrepareForBuild">
> 	  <Copy
> SourceFiles="$(MSBuildThisFileDirectory)..\..\lib\native\address-model-32\lib\boost_atomic-vc100-mt-1_62.dll"
> 		  	DestinationFolder="$(OutDir)"
> Condition="'$(Configuration)|$(Platform)'=='Release|Win32'" />
> 	  <Copy
> SourceFiles="$(MSBuildThisFileDirectory)..\..\lib\native\address-model-32\lib\boost_atomic-vc100-mt-gd-1_62.dll"
> 		  	DestinationFolder="$(OutDir)"
> Condition="'$(Configuration)|$(Platform)'=='Debug|Win32'" />
>   </Target>
>   
> </Project>
>
>
> (General)
>
> So, now I am dynamically linking to all boost libraries and if I use the
> following code, I get the expected results. If I statically link, all the if
> conditions evaluate to false. This seems like a very big problem to me and
> very unexpected.
>
> //--------------------------------------------------------------------------------------------------
> std::string ClientSocketASIO::ErrorCodeToString(const
> boost::system::error_code & errorCode)
> {
>     std::ostringstream debugMsg;
>     debugMsg << " Error Category: " << errorCode.category().name() << ". "
>              << " Error Message: "  << errorCode.message() << ". ";
>
>     // IMPORTANT - These comparisons only work if you dynamically link boost
> libraries
>     //             Because boost chose to implement
> boost::system::error_category::operator == by comparing addresses
>     //             The addresses are different in one library and the other
> when statically linking.
>     //
>     // We use make_error_code macro to make the correct category as well as
> error code value.
>     // Error code value is not unique and can be duplicated in more than one
> category.
>     if (errorCode ==
> make_error_code(boost::asio::error::connection_refused))
>     {
>         debugMsg << ". Connection Refused";
>     }
>     else if (errorCode == make_error_code(boost::asio::error::eof))
>     {
>         debugMsg << ". Server has disconnected.";
>     }
>     else
>     {
>         debugMsg << ". boost::system::error_code has not been mapped to a
> meaningful message.";
>     }
>
>     return debugMsg.str();
> }
>
> Why would the authors use address comparison for the
> boost::system::error_category and leave us getting different results if we
> statically link vs dynamically link?
>
> Also, is my error_code comparison now the proper and correct way to compare
> error codes?
>
>
>
>
> --
> View this message in context: http://boost.2283326.n4.nabble.com/Compare-boost-system-error-category-tp4692861p4692910.html
> Sent from the Boost - Users mailing list archive at Nabble.com.
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