Details
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Bug
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Resolution: Fixed
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P2: Important
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6.3.2, 6.5.0
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Windows 10
Visual Studio 2019 16.11.19
MSVC 19.29.30146
CMake version 3.24.2
Ninja 1.11.1
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Windows
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e0ec19de4 (dev), 99aeb7594 (6.5), 470fee321 (dev), 1e303cdbd (6.6), a945c542d (6.5), b6f777824 (tqtc/lts-6.2), ec5fee55e (6.5.2)
Description
Hi,
I was trying out the new qt_add_qml_module CMake-macro that came with Qt 6.2 to create reusable QML modules.
In Visual Studio I noticed that it will always re-build rcc files even when nothing has changed.
I used the following example project https://gitlab.com/kelteseth/qt6-cmake-qml-plugin-example-project and QT 6.3.2 via vcpkg.
After a full project build and without changing any source files, the rcc-generated files still always get recompiled when MSBuild gets invoked:
1>------ Build started: Project: DownloadManager_qmlcache_autogen, Configuration: Debug x64 ------ 2>------ Build started: Project: DownloadManagerplugin_init_autogen, Configuration: Debug x64 ------ 3>------ Build started: Project: TestProject_qmlimportscan, Configuration: Debug x64 ------ 4>------ Build started: Project: DownloadManager_autogen, Configuration: Debug x64 ------ 1>Automatic MOC for target DownloadManager_qmlcache 2>Automatic MOC for target DownloadManagerplugin_init 4>Automatic MOC for target DownloadManager 5>------ Build started: Project: DownloadManager_automoc_json_extraction, Configuration: Debug x64 ------ 5>Running AUTOMOC file extraction for target DownloadManager 6>------ Build started: Project: DownloadManager, Configuration: Debug x64 ------ 6>Running moc --collect-json for target DownloadManager 6>Automatic QML type registration for target DownloadManager 6>Generating .rcc/qmlcache/DownloadManager_DownloadManager/TestMain_qml.cpp 6>Generating .rcc/qmlcache/DownloadManager_DownloadManager/DownloadManagerControls_qml.cpp 6>DownloadManagerControls_qml.cpp 6>TestMain_qml.cpp 6>downloadmanager_qmltyperegistrations.cpp 6>DownloadManager.vcxproj -> F:\Temp\testbuild\Debug\DownloadManager.lib 7>------ Build started: Project: TestProject, Configuration: Debug x64 ------ 7>Automatic MOC for target TestProject 7>TestProject.vcxproj -> F:\Temp\testbuild\Debug\TestProject.exe ========== Build: 7 succeeded, 0 failed, 7 up-to-date, 0 skipped ==========
Even with only two QML-resources, the build already takes more than 4 seconds every time. The Visual Studio re-build times on larger projects with more resources would be horribly slow.
Through the verbose MSBuild output I figured out that the source of the resource-build being triggered lies in the _automoc_json_extraction Utility-target. It gets re-generated every time because the output file mentioned in the custom build step is never created:
<ItemGroup> <CustomBuild Include="F:\Temp\testbuild\CMakeFiles\da9815ec55e86dcf9777446cf05e6423\DownloadManager_automoc_json_extraction.rule"> <Message Condition="'$(Configuration)|$(Platform)'=='Debug|x64'">Running AUTOMOC file extraction for target DownloadManager</Message> <Command Condition="'$(Configuration)|$(Platform)'=='Debug|x64'">setlocal G:\vcpkg\installed\x64-windows\tools\Qt6\bin\cmake_automoc_parser.exe --cmake-autogen-cache-file F:/Temp/testbuild/CMakeFiles/DownloadManager_autogen.dir/ParseCache_Debug.txt --cmake-autogen-info-file F:/Temp/testbuild/CMakeFiles/DownloadManager_autogen.dir/AutogenInfo.json --output-file-path F:/Temp/testbuild/meta_types/DownloadManager_json_file_list.txt --timestamp-file-path F:/Temp/testbuild/meta_types/DownloadManager_json_file_list.txt.timestamp --cmake-autogen-include-dir-path F:/Temp/testbuild/DownloadManager_autogen/include_Debug --cmake-multi-config if %errorlevel% neq 0 goto :cmEnd :cmEnd endlocal & call :cmErrorLevel %errorlevel% & goto :cmDone :cmErrorLevel exit /b %1 :cmDone if %errorlevel% neq 0 goto :VCEnd</Command> <AdditionalInputs Condition="'$(Configuration)|$(Platform)'=='Debug|x64'">G:\vcpkg\installed\x64-windows\tools\Qt6\bin\cmake_automoc_parser.exe;%(AdditionalInputs)</AdditionalInputs> <Outputs Condition="'$(Configuration)|$(Platform)'=='Debug|x64'">F:\Temp\testbuild\CMakeFiles\DownloadManager_automoc_json_extraction</Outputs> <LinkObjects Condition="'$(Configuration)|$(Platform)'=='Debug|x64'">false</LinkObjects> <VerifyInputsAndOutputsExist Condition="'$(Configuration)|$(Platform)'=='Debug|x64'">false</VerifyInputsAndOutputsExist>
If i manually create the file "F:\Temp\testbuild\CMakeFiles\DownloadManager_automoc_json_extraction" the target is not re-built, but consequentially actual re-builds may not get triggered when necessary.
When using Ninja as the CMake generator, everything behaves as expected and no files are re-built without changes. Thus, this seems to be an issue that specifically affects only the Visual Studio CMake generators.
Attachments
Issue Links
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- Closed
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- Closed
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| For Gerrit Dashboard: QTBUG-106683 | ||||||
|---|---|---|---|---|---|---|
| # | Subject | Branch | Project | Status | CR | V |
| 478439,4 | CMake: Fix unnecessary rebuilds in Visual Studio projects | dev | qt/qtbase | Status: MERGED | +2 | 0 |
| 481616,2 | CMake: Fix unnecessary rebuilds in Visual Studio projects | 6.5 | qt/qtbase | Status: MERGED | +2 | 0 |
| 484422,3 | CMake: Remove superfluous depfile in QML type registration | dev | qt/qtdeclarative | Status: MERGED | +2 | 0 |
| 484796,2 | CMake: Remove superfluous depfile in QML type registration | 6.6 | qt/qtdeclarative | Status: MERGED | +2 | 0 |
| 484797,2 | CMake: Remove superfluous depfile in QML type registration | 6.5 | qt/qtdeclarative | Status: MERGED | +2 | 0 |
| 484806,3 | CMake: Remove superfluous depfile in QML type registration | tqtc/lts-6.2 | qt/tqtc-qtdeclarative | Status: MERGED | +2 | 0 |
| 484865,3 | CMake: Remove superfluous depfile in QML type registration | 6.5.2 | qt/qtdeclarative | Status: MERGED | +2 | 0 |