Qt MOC multiple files in parallel with MSBuild - visual-studio-2010

Question

Good morning!
I know there is already this question here: Qt Moc'ing multiple files in parallel under msbuild but I would not show up this old question.
I work under Visual Studio 2010 and I've got to speed up the compilation time of my app. I use all flags like /MP with MSBuild -j with Make etc... The last step of the optimization is to parallelize MOC'ing steps. They are painfully slow and I googled a lot and I didn't find a solution.
I know that jom exists but it uses nmake and I've got to use MSBuild.
If someone has already heard a solution, it should be really cool!
Have a nice day!

Answer 1

If you generate VC project file with qmake from qt *.pro , it generates it in a way that mocables are compiled in one thread. The only way I know to workaround this behavior is to explicitly call jom for moc pre-processing.
I have only VS2012 (win32-msvc2012), but I used to do the similar thing for VS2010 (win32-msvc2010 in your case)
To do so you should automate the following steps:
Create VC project from pro file through qmake:
qmake -spec win32-msvc2012 -tp vc -o ${path-to-target}/${your-project}.vcxproj ${path-to-source}/${your-qt-pro}.pro
Create makefile from pro file through qmake:
qmake -spec win32-msvc2012 CONFIG+=release -o ${path-to-target}/Makefile', ${path-to-source}/${your-qt-pro}.pro
Create the following .bat file next to vcproj file (put %VS100COMNTOOLS% for vc2010 and x86/x64 for arch):
call "%VS110COMNTOOLS%\..\..\VC\vcvarsall.bat" ${arch}
md build\release\generated
${environment.dir}\bin\jom.exe -j 16 /F Makefile.release mocables
To do debug build change 'release' to 'debug' (or introduce a variable)
Now it is necessary to edit VC project file. Here is what you need to find/replace (using regular expressions):
1) For all includes (tags Project->ItemGroup->CustomBuild Include that contains *.h files:
find: </CustomBuild>
replace to: <ExcludedFromBuild>true</ExcludedFromBuild>
</CustomBuild>
2) for Project->ItemDefinitionGroup:
find: </Link>
replace to: </Link>
<PreBuildEvent>
<Command>build_moc.bat</Command>
</PreBuildEvent>
3) for Project->ItemDefinitionGroup:
- find: <ItemDefinitionGroup>
- replace to: <Target Name="BeforeClean">
<Message Text="Cleaning moc generated files"/>
<Exec Command="del \$\(ProjectDir\)..\\\$(Platform\)\\build\\${arch}\\generated\\moc_*.* /F /Q" />
</Target>
<ItemDefinitionGroup>
I automate it with Maven, so here is the code snippet for the reference:
build_moc.bat:
cd %1
md build\%2\generated
c:\\develop\\buildenv\bin\jom.exe -j 16 /F Makefile.%2 mocables
maven script that does replacements (maven-replacer-plugin config):
<!-- Disabling moc preprocessor steps, since we do it with jom -->
<replacement>
<xpath>//Project/ItemGroup/CustomBuild[contains(#Include,'.h')]</xpath>
<token><![CDATA[</CustomBuild>]]></token>
<value><![CDATA[
<ExcludedFromBuild>true</ExcludedFromBuild>
</CustomBuild>
]]></value>
</replacement>
<!-- Adding moc preprocessor steps with jom -->
<replacement>
<xpath>//Project/ItemDefinitionGroup[not(#*)]</xpath>
<token><![CDATA[</Link>]]></token>
<value><![CDATA[
</Link>
<PreBuildEvent>
<Command>\$\(ProjectDir\)../${arch}/build_moc.bat \$\(ProjectDir\)../${arch} \$\(Configuration\)</Command>
</PreBuildEvent>
]]></value>
</replacement>
<!-- Cleaning moc files -->
<replacement>
<token><![CDATA[<ItemDefinitionGroup>]]></token>
<value><![CDATA[
<Target Name="BeforeClean">
<Message Text="Cleaning moc generated files"/>
<Exec Command="del \$\(ProjectDir\)..\\\$\(Platform\)\\build\\${arch}\\generated\\moc_*.* /F /Q" />
</Target>
<ItemDefinitionGroup>
]]></value>
</replacement>
I hope this helps