Improve intellisense performance for Qt projects

 * Avoid running background builds when projects are loaded or changed.
 * Add outer/inner build targets also for design time builds.
 * Add project option to enable/disable running Qt tools in design-time.
 * Stop using project system notification subscriptions.
 * Detect relevant project changes using only DTE events.

Change-Id: I7fe0508b2d9ed63c1e3f3b2741ee57ffad366527
Reviewed-by: Karsten Heimrich <karsten.heimrich@qt.io>

12 files changed, 309 insertions, 158 deletions

diff --git a/QtMSBuild/QtMSBuild.csproj b/QtMSBuild/QtMSBuild.csproj
index 3e2a0e0e..a6140a9d 100644
--- a/QtMSBuild/QtMSBuild.csproj
+++ b/QtMSBuild/QtMSBuild.csproj
@@ -172,6 +172,10 @@
       <SubType>Designer</SubType>
       <CopyToOutputDirectory>Always</CopyToOutputDirectory>
     </Content>
+    <Content Include="QtMSBuild\qt_inner.targets">
+      <SubType>Designer</SubType>
+      <CopyToOutputDirectory>Always</CopyToOutputDirectory>
+    </Content>
     <!--
     ///////////////////////////////////////////////////////////////////////////////////////////////
     // Qt/MSBuild moc property pages and targets
diff --git a/QtMSBuild/QtMsBuild/qt_defaults.props b/QtMSBuild/QtMsBuild/qt_defaults.props
index 83f7c8e5..2d212157 100644
--- a/QtMSBuild/QtMsBuild/qt_defaults.props
+++ b/QtMSBuild/QtMsBuild/qt_defaults.props
@@ -71,6 +71,9 @@
     <QtPathBinaries>bin</QtPathBinaries>
     <QtPathLibraryExecutables>bin</QtPathLibraryExecutables>
 
+    <!--// Run Qt tools during design-time build -->
+    <QtToolsDesignTime>true</QtToolsDesignTime>
+
     <!--// qmake template -->
     <QtQMakeTemplate>vcapp</QtQMakeTemplate>
 
diff --git a/QtMSBuild/QtMsBuild/qt_globals.targets b/QtMSBuild/QtMsBuild/qt_globals.targets
index 661bc144..cddba5d0 100644
--- a/QtMSBuild/QtMsBuild/qt_globals.targets
+++ b/QtMSBuild/QtMsBuild/qt_globals.targets
@@ -84,6 +84,29 @@
 
   <!--
   /////////////////////////////////////////////////////////////////////////////////////////////////
+  // Set up inner build if Qt vars property file is outdated
+  // -->
+  <PropertyGroup Condition="'$(QtInnerBuild)' == ''">
+    <QtVarsOutdated>false</QtVarsOutdated>
+    <QtVarsOutdated
+      Condition="!Exists('$(QtVarsFilePath)')
+        OR '$(QtBkup_QtInstall)'                != '$(QtInstall)'
+        OR '$(QtBkup_QtModules)'                != '$(QtModules)'
+        OR '$(QtBkup_QtPathBinaries)'           != '$(QtPathBinaries)'
+        OR '$(QtBkup_QtPathLibraryExecutables)' != '$(QtPathLibraryExecutables)'
+        OR '$(QtBkup_QtHeaderSearchPath)'       != '$(QtHeaderSearchPath)'
+        OR '$(QtBkup_QtLibrarySearchPath)'      != '$(QtLibrarySearchPath)'
+        OR '$(QtBkup_QtVars)'                   != '$(QtVars)'
+        OR '$(QtBkup_QMakeCodeLines)'           != '$(QMakeCodeLines)'
+        OR '$(QtBkup_QtBuildConfig)'            != '$(QtBuildConfig)'"
+    >true</QtVarsOutdated>
+  </PropertyGroup>
+
+  <!-- // Enable inner build targets -->
+  <Import Condition="'$(QtVarsOutdated)' == 'true'" Project="qt_inner.targets"/>
+
+  <!--
+  /////////////////////////////////////////////////////////////////////////////////////////////////
   /// TARGET QtGetDefaultClCompile
   /////////////////////////////////////////////////////////////////////////////////////////////////
   // Get default C++ properties
@@ -201,7 +224,8 @@
                OR ('$(project_changed)' == 'true' AND '$(log_hash)' != '$(work_hash)')"
         >true</do_work>
       <skip_work
-        Condition="'$(do_work)' != 'true' OR '$(DesignTimeBuild)' == 'true'"
+        Condition="'$(do_work)' != 'true'
+          OR ('$(QtDesignTimeBuild)' == 'true' AND '$(QtToolsDesignTime)' != 'true')"
         >true</skip_work>
     </PropertyGroup>
 
@@ -268,8 +292,7 @@
     // -->
     <QtRunWork
       Condition="'$(ApplicationType)' != 'Linux' AND '@(QtWork)' != ''
-        AND '%(QtWork.ParallelBuild)' == 'true'
-        AND '$(DesignTimeBuild)' != 'true'"
+        AND '%(QtWork.ParallelBuild)' == 'true'"
       QtWork="@(QtWork)" QtMaxProcs="$(QtMaxProcs)" QtDebug="$(QtDebug)">
       <Output TaskParameter="Result" ItemName="QtWorkResult" />
     </QtRunWork>
@@ -280,8 +303,7 @@
     // -->
     <QtRunWork
       Condition="'$(ApplicationType)' != 'Linux' AND '@(QtWork)' != ''
-        AND '%(QtWork.ParallelBuild)' != 'true'
-        AND '$(DesignTimeBuild)' != 'true'"
+        AND '%(QtWork.ParallelBuild)' != 'true'"
       QtWork="@(QtWork)" QtMaxProcs="1" QtDebug="$(QtDebug)">
       <Output TaskParameter="Result" ItemName="QtWorkResult" />
     </QtRunWork>
@@ -293,13 +315,13 @@
     <!-- // Translate local paths to host paths -->
     <Flatten
       Condition="'$(ApplicationType)' == 'Linux'
-        AND '@(QtWork)' != '' AND '$(DesignTimeBuild)' != 'true'"
+        AND '@(QtWork)' != '' AND '$(QtDesignTimeBuild)' != 'true'"
       Items="@(QtWork)" Metadata="ResourceFiles">
       <Output TaskParameter="Result" ItemName="ResourceFiles"/>
     </Flatten>
     <ItemGroup
       Condition="'$(ApplicationType)' == 'Linux'
-        AND '@(QtWork)' != '' AND '$(DesignTimeBuild)' != 'true'">
+        AND '@(QtWork)' != '' AND '$(QtDesignTimeBuild)' != 'true'">
       <LocalPath Include="%(QtWork.Identity)">
         <Name>InputPath</Name>
         <Item>%(QtWork.Identity)</Item>
@@ -320,7 +342,7 @@
     </ItemGroup>
     <HostTranslatePaths
       Condition="'$(ApplicationType)' == 'Linux'
-        AND '@(QtWork)' != '' AND '$(DesignTimeBuild)' != 'true'"
+        AND '@(QtWork)' != '' AND '$(QtDesignTimeBuild)' != 'true'"
       Items="@(LocalPath)" Names="InputPath;OutputPath">
       <Output TaskParameter="Result" ItemName="HostPath"/>
     </HostTranslatePaths>
@@ -332,7 +354,7 @@
     <!-- // Run command -->
     <HostExec
       Condition="'$(ApplicationType)' == 'Linux'
-        AND '%(Identity)' != '' AND '$(DesignTimeBuild)' != 'true'"
+        AND '%(Identity)' != '' AND '$(QtDesignTimeBuild)' != 'true'"
       Message="@(QtWork->'%(WorkType) %(Identity)')"
       Command="@(QtWork->'%(ToolPath) %(Options)')"
       Inputs="@(InputPath)"
@@ -344,7 +366,7 @@
     <!-- // Generate result item -->
     <ItemGroup
       Condition="'$(ApplicationType)' == 'Linux'
-        AND '@(QtWork)' != '' AND '$(DesignTimeBuild)' != 'true'">
+        AND '@(QtWork)' != '' AND '$(QtDesignTimeBuild)' != 'true'">
       <QtWorkResult Include="@(QtWork)">
         <ExitCode>0</ExitCode>
       </QtWorkResult>
@@ -354,9 +376,11 @@
     ///////////////////////////////////////////////////////////////////////////////////////////////
     // Save tracking log of files read during build; used by VS to check the up-to-date status
     // -->
-    <ItemGroup Condition="'$(DesignTimeBuild)' != 'true' AND '$(QtVSToolsBuild)' != 'true'">
+    <ItemGroup>
       <read_log Include="^%(QtWorkResult.FullPath);%(QtWorkResult.AdditionalDependencies)"
-        Condition="'%(QtWorkResult.ExitCode)' == '0' AND '%(QtWorkResult.DisableLog)' != 'true'">
+        Condition="'%(QtWorkResult.ExitCode)' == '0'
+               AND '%(QtWorkResult.DisableLog)' != 'true'
+               AND '%(QtWorkResult.Skipped)' != 'true'">
         <WorkType>%(QtWorkResult.WorkType)</WorkType>
       </read_log>
       <read_log>
@@ -377,9 +401,11 @@
     ///////////////////////////////////////////////////////////////////////////////////////////////
     // Save tracking log of files written during build; used by VS to check the up-to-date status
     // -->
-    <ItemGroup Condition="'$(DesignTimeBuild)' != 'true' AND '$(QtVSToolsBuild)' != 'true'">
+    <ItemGroup>
       <write_log Include="^%(QtWorkResult.FullPath);%(QtWorkResult.OutputFile)"
-        Condition="'%(QtWorkResult.ExitCode)' == '0' AND '%(QtWorkResult.DisableLog)' != 'true'">
+        Condition="'%(QtWorkResult.ExitCode)' == '0'
+               AND '%(QtWorkResult.DisableLog)' != 'true'
+               AND '%(QtWorkResult.Skipped)' != 'true'">
         <WorkType>%(QtWorkResult.WorkType)</WorkType>
       </write_log>
       <write_log>
@@ -398,7 +424,7 @@
     ///////////////////////////////////////////////////////////////////////////////////////////////
     // Log output files; this is used by VS to determine what files to delete on "Clean"
     // -->
-    <ItemGroup Condition="'$(DesignTimeBuild)' != 'true' AND '$(QtVSToolsBuild)' != 'true'">
+    <ItemGroup>
       <clean_log Include="%(QtWorkResult.OutputFile)"
         Condition="'%(QtWorkResult.ExitCode)' == '0'">
         <Source>@(QtWorkResult, '|')</Source>
@@ -414,7 +440,7 @@
     ///////////////////////////////////////////////////////////////////////////////////////////////
     // Log calls to Qt tools; used in QtWorkPrepare to detect changes to the options of Qt tools
     // -->
-    <WriteLinesToFile Condition="'@(QtWorkLog)' != '' AND '$(DesignTimeBuild)' != 'true'"
+    <WriteLinesToFile Condition="'@(QtWorkLog)' != ''"
       File="$(QtLogFilePath)"
       Lines="@(QtWorkLog->'%(Identity)|%(Hash)')"
       Overwrite="true" Encoding="Unicode"/>
@@ -425,8 +451,7 @@
     // -->
     <Error
       Condition="'%(QtWorkResult.ExitCode)' != ''
-        AND '%(QtWorkResult.ExitCode)' != '0'
-        AND '$(DesignTimeBuild)' != 'true'"
+        AND '%(QtWorkResult.ExitCode)' != '0'"
       File="%(QtWorkResult.Identity)" Code="%(QtWorkResult.ExitCode)"
       Text="%(QtWorkResult.WorkType) (%(QtWorkResult.ToolPath))"/>
 
@@ -673,48 +698,13 @@
   // -->
   <Target
     Name="Qt"
-    DependsOnTargets="QtPrepare;QtWork;QtSetAdditionalOptions"
-    BeforeTargets="FixupCLCompileOptions">
+    DependsOnTargets="QtPrepare;QtWork;QtSetAdditionalOptions">
     <CriticalSection Lock="false" Name="$(ProjectGuid)" />
     <OnError ExecuteTargets="QtLeaveCriticalSection_OnError"/>
   </Target>
 
   <!--
   /////////////////////////////////////////////////////////////////////////////////////////////////
-  /// TARGET QtOuterBuild
-  /////////////////////////////////////////////////////////////////////////////////////////////////
-  // Run targets in $(QtOuterBuildDependsOn) and then recursively invoke build
-  // -->
-  <Target Name="QtOuterBuild" DependsOnTargets="$(QtOuterBuildDependsOn)">
-    <!--// Invoke inner build: recursive build in second MSBuild instance -->
-    <MSBuild
-      Projects="$(MSBuildProjectFullPath)"
-      Targets="Build"
-      Properties="QtInnerBuild=$(MSBuildProjectFullPath);RandomFileName=$(RandomFileName);BuildProjectReferences=false">
-    </MSBuild>
-    <OnError ExecuteTargets="QtLeaveCriticalSection_OnError"/>
-  </Target>
-
-  <PropertyGroup
-    Condition="'$(QtInnerBuild)' == '' AND '$(DesignTimeBuild)' != 'true'">
-    <!--// Outer build: invoke inner build -->
-    <BuildDependsOn>
-      $(QtOuterBuildPrepare);
-      QtOuterBuild;
-      $(QtOuterBuildFinalize)
-    </BuildDependsOn>
-    <QtInnerBuild>$(MSBuildProjectFullPath)</QtInnerBuild>
-    <RandomFileName>$([System.IO.Path]::GetRandomFileName())</RandomFileName>
-  </PropertyGroup>
-
-  <PropertyGroup
-    Condition="'$(QtInnerBuild)' != '$(MSBuildProjectFullPath)' AND '$(DesignTimeBuild)' != 'true'">
-    <!--// Dependent project inner build: skip build -->
-    <BuildDependsOn>$(QtOuterBuildPrepare);$(QtOuterBuildFinalize)</BuildDependsOn>
-  </PropertyGroup>
-
-  <!--
-  /////////////////////////////////////////////////////////////////////////////////////////////////
   /// TARGET QtEnterCriticalSection_... / QtLeaveCriticalSection_InitializeBuildStatus
   /////////////////////////////////////////////////////////////////////////////////////////////////
   // Synchronize calls to InitializeBuildStatus
diff --git a/QtMSBuild/QtMsBuild/qt_inner.targets b/QtMSBuild/QtMsBuild/qt_inner.targets
new file mode 100644
index 00000000..a0675838
--- /dev/null
+++ b/QtMSBuild/QtMsBuild/qt_inner.targets
@@ -0,0 +1,138 @@
+<?xml version="1.0" encoding="utf-8"?>
+<!--
+/****************************************************************************
+**
+** Copyright (C) 2022 The Qt Company Ltd.
+** Contact: https://www.qt.io/licensing/
+**
+** This file is part of the Qt VS Tools.
+**
+** $QT_BEGIN_LICENSE:GPL-EXCEPT$
+** Commercial License Usage
+** Licensees holding valid commercial Qt licenses may use this file in
+** accordance with the commercial license agreement provided with the
+** Software or, alternatively, in accordance with the terms contained in
+** a written agreement between you and The Qt Company. For licensing terms
+** and conditions see https://www.qt.io/terms-conditions. For further
+** information use the contact form at https://www.qt.io/contact-us.
+**
+** GNU General Public License Usage
+** Alternatively, this file may be used under the terms of the GNU
+** General Public License version 3 as published by the Free Software
+** Foundation with exceptions as appearing in the file LICENSE.GPL3-EXCEPT
+** included in the packaging of this file. Please review the following
+** information to ensure the GNU General Public License requirements will
+** be met: https://www.gnu.org/licenses/gpl-3.0.html.
+**
+** $QT_END_LICENSE$
+**
+****************************************************************************/
+-->
+<Project xmlns="http://schemas.microsoft.com/developer/msbuild/2003">
+
+  <PropertyGroup
+    Condition="'$(QtInnerBuild)' == ''">
+    <!--// Outer build: invoke inner build -->
+    <BuildDependsOn>
+      $(QtOuterBuildPrepare);
+      QtOuterBuild;
+      $(QtOuterBuildFinalize)
+    </BuildDependsOn>
+    <QtInnerBuild>$(MSBuildProjectFullPath)</QtInnerBuild>
+    <RandomFileName>$([System.IO.Path]::GetRandomFileName())</RandomFileName>
+  </PropertyGroup>
+
+  <PropertyGroup
+    Condition="'$(QtInnerBuild)' != '$(MSBuildProjectFullPath)'">
+    <!--// Dependent project inner build: skip build -->
+    <BuildDependsOn>$(QtOuterBuildPrepare);$(QtOuterBuildFinalize)</BuildDependsOn>
+  </PropertyGroup>
+
+  <!--
+  /////////////////////////////////////////////////////////////////////////////////////////////////
+  /// TARGET QtOuterBuild
+  /////////////////////////////////////////////////////////////////////////////////////////////////
+  // Run targets in $(QtOuterBuildDependsOn) and then recursively invoke build
+  // -->
+  <Target Name="QtOuterBuild" DependsOnTargets="$(QtOuterBuildDependsOn)">
+    <!--// Invoke inner build: recursive build in second MSBuild instance -->
+    <MSBuild
+      Projects="$(MSBuildProjectFullPath)"
+      Targets="Build"
+      Properties="QtInnerBuild=$(MSBuildProjectFullPath);RandomFileName=$(RandomFileName);BuildProjectReferences=false">
+    </MSBuild>
+    <OnError ExecuteTargets="QtLeaveCriticalSection_OnError"/>
+  </Target>
+
+  <!--
+  /////////////////////////////////////////////////////////////////////////////////////////////////
+  /// TARGET GetClCommandLineForReference
+  /////////////////////////////////////////////////////////////////////////////////////////////////
+  //
+  // -->
+  <Target
+    Name="GetClCommandLineForReference"
+    DependsOnTargets="$(QtOuterBuildDependsOn)"
+    Returns="@(ClCommandLineForReference)">
+    <MSBuild
+      Projects="$(MSBuildProjectFullPath)"
+      Targets="GetClCommandLineForReference"
+      Properties="QtInnerBuild=$(MSBuildProjectFullPath);RandomFileName=$(RandomFileName);BuildProjectReferences=false">
+      <Output TaskParameter="TargetOutputs" ItemName="ClCommandLineForReference"/>
+    </MSBuild>
+  </Target>
+
+  <!--
+  /////////////////////////////////////////////////////////////////////////////////////////////////
+  /// TARGET GetGeneratedFiles
+  /////////////////////////////////////////////////////////////////////////////////////////////////
+  //
+  // -->
+  <Target
+    Name="GetGeneratedFiles"
+    DependsOnTargets="$(QtOuterBuildDependsOn)"
+    Returns="@(_GeneratedFiles)">
+    <MSBuild
+      Projects="$(MSBuildProjectFullPath)"
+      Targets="GetGeneratedFiles"
+      Properties="QtInnerBuild=$(MSBuildProjectFullPath);RandomFileName=$(RandomFileName);BuildProjectReferences=false">
+      <Output TaskParameter="TargetOutputs" ItemName="_GeneratedFiles"/>
+    </MSBuild>
+  </Target>
+
+  <!--
+  /////////////////////////////////////////////////////////////////////////////////////////////////
+  /// TARGET GetProjectReferencesInfo
+  /////////////////////////////////////////////////////////////////////////////////////////////////
+  //
+  // -->
+  <Target
+    Name="GetProjectReferencesInfo"
+    DependsOnTargets="$(QtOuterBuildDependsOn)"
+    Returns="@(_ProjectReferencesInfo)">
+    <MSBuild
+      Projects="$(MSBuildProjectFullPath)"
+      Targets="GetProjectReferencesInfo"
+      Properties="QtInnerBuild=$(MSBuildProjectFullPath);RandomFileName=$(RandomFileName);BuildProjectReferences=false">
+      <Output TaskParameter="TargetOutputs" ItemName="_ProjectReferencesInfo"/>
+    </MSBuild>
+  </Target>
+
+  <!--
+  /////////////////////////////////////////////////////////////////////////////////////////////////
+  /// TARGET GetClCommandLines
+  /////////////////////////////////////////////////////////////////////////////////////////////////
+  //
+  // -->
+  <Target
+    Name="GetClCommandLines"
+    DependsOnTargets="$(QtOuterBuildDependsOn)"
+    Returns="@(ClCommandLines)">
+    <MSBuild
+      Projects="$(MSBuildProjectFullPath)"
+      Targets="GetClCommandLines"
+      Properties="QtInnerBuild=$(MSBuildProjectFullPath);RandomFileName=$(RandomFileName);BuildProjectReferences=false">
+      <Output TaskParameter="TargetOutputs" ItemName="ClCommandLines"/>
+    </MSBuild>
+  </Target>
+</Project>
diff --git a/QtMSBuild/QtMsBuild/qt_private.props b/QtMSBuild/QtMsBuild/qt_private.props
index f688ae1e..007d87a9 100644
--- a/QtMSBuild/QtMsBuild/qt_private.props
+++ b/QtMSBuild/QtMsBuild/qt_private.props
@@ -57,6 +57,18 @@
 
   <!--
   /////////////////////////////////////////////////////////////////////////////////////////////////
+  // Check if design-time build
+  // -->
+  <PropertyGroup>
+    <QtDesignTimeBuild>false</QtDesignTimeBuild>
+    <QtDesignTimeBuild
+      Condition="'$(DesignTimeBuild)' == 'true'
+              OR '$(QtVSToolsBuild)'  == 'true'"
+      >true</QtDesignTimeBuild>
+  </PropertyGroup>
+
+  <!--
+  /////////////////////////////////////////////////////////////////////////////////////////////////
   // Setup Qt installation path
   // -->
   <PropertyGroup Condition="'$(QtVsProjectSettings)' == 'true'">
@@ -112,21 +124,29 @@
       >$([System.String]::Copy($([System.IO.File]::ReadAllText('$(QtVarsIndexPathDesignTime)'))).Replace('&#xD;&#xA;',''))</QtVarsDesignTime>
   </PropertyGroup>
 
-  <!--// Import Qt variables (full build) -->
-  <Import
-    Condition="'$(DesignTimeBuild)' != 'true' AND Exists('$(QtVarsFilePath)')"
-    Project="$(QtVarsFilePath)"/>
+  <PropertyGroup>
+    <!--// Path to Qt variables .props: full build -->
+    <QtVarsImportPath
+      Condition="'$(QtDesignTimeBuild)' != 'true'
+        AND Exists('$(QtVarsFilePath)')"
+      >$(QtVarsFilePath)</QtVarsImportPath>
 
-  <!--// Import Qt variables (design-time build) -->
-  <Import
-    Condition="'$(DesignTimeBuild)' == 'true' AND Exists('$(QtVarsDesignTime)')"
-    Project="$(QtVarsDesignTime)"/>
+    <!--// Path to Qt variables .props: design-time build -->
+    <QtVarsImportPath
+      Condition="'$(QtDesignTimeBuild)' == 'true'
+        AND Exists('$(QtVarsDesignTime)')"
+      >$(QtVarsDesignTime)</QtVarsImportPath>
 
-  <!--// Import Qt variables (fall-back) -->
-  <Import
-    Condition=
-"'$(DesignTimeBuild)' == 'true' AND !Exists('$(QtVarsDesignTime)') AND Exists('$(QtVarsFilePath)')"
-    Project="$(QtVarsFilePath)"/>
+    <!--// Path to Qt variables .props: fall-back -->
+    <QtVarsImportPath
+      Condition="'$(QtDesignTimeBuild)' == 'true'
+        AND !Exists('$(QtVarsDesignTime)')
+        AND  Exists('$(QtVarsFilePath)')"
+      >$(QtVarsFilePath)</QtVarsImportPath>
+  </PropertyGroup>
+
+  <!--// Import Qt vars property file -->
+  <Import Condition="Exists('$(QtVarsImportPath)')" Project="$(QtVarsImportPath)"/>
 
   <!--
   /////////////////////////////////////////////////////////////////////////////////////////////////
diff --git a/QtMSBuild/QtMsBuild/qt_settings.xml b/QtMSBuild/QtMsBuild/qt_settings.xml
index 9c1b2549..53b2f526 100644
--- a/QtMSBuild/QtMsBuild/qt_settings.xml
+++ b/QtMSBuild/QtMsBuild/qt_settings.xml
@@ -100,6 +100,14 @@
     Category="QtSettings_01_General"
     DisplayName="Run Deployment Tool"
     Description="Select whether Qt for Windows Deployment Tool (windeployqt) should be called after build."/>
+  <EnumProperty
+    Name="QtToolsDesignTime"
+    Category="QtSettings_01_General"
+    DisplayName="Design Time Build"
+    Description="Run Qt tools during IntelliSense builds.">
+    <EnumValue Name="true" DisplayName="Run Qt Tools"/>
+    <EnumValue Name="false" DisplayName="Skip Qt Tools"/>
+  </EnumProperty>
   <StringProperty
     Name="QtPathBinaries"
     Category="QtSettings_02_Paths"
diff --git a/QtMSBuild/QtMsBuild/qt_vars.targets b/QtMSBuild/QtMsBuild/qt_vars.targets
index 174b9b56..5d6f08da 100644
--- a/QtMSBuild/QtMsBuild/qt_vars.targets
+++ b/QtMSBuild/QtMsBuild/qt_vars.targets
@@ -501,15 +501,15 @@
     <!--// In design-time, copy generated .props to randomly named file -->
     <PropertyGroup>
       <QtVarsDesignTimeNew
-        Condition="'$(ErrorLevel)' == '0' AND '$(QtVSToolsBuild)' == 'true'"
+        Condition="'$(ErrorLevel)' == '0' AND '$(QtDesignTimeBuild)' == 'true'"
         >$([System.IO.Path]::Combine('$(TEMP)','$([System.IO.Path]::GetRandomFileName()).designtime.props'))
       </QtVarsDesignTimeNew>
     </PropertyGroup>
     <Copy
-      Condition="'$(ErrorLevel)' == '0' AND '$(QtVSToolsBuild)' == 'true'"
+      Condition="'$(ErrorLevel)' == '0' AND '$(QtDesignTimeBuild)' == 'true'"
       SourceFiles="$(QtVarsFilePath)" DestinationFiles="$(QtVarsDesignTimeNew)"/>
     <WriteLinesToFile
-      Condition="'$(ErrorLevel)' == '0' AND '$(QtVSToolsBuild)' == 'true'"
+      Condition="'$(ErrorLevel)' == '0' AND '$(QtDesignTimeBuild)' == 'true'"
       File="$(QtVarsIndexPathDesignTime)" Overwrite="true" Lines="$(QtVarsDesignTimeNew)"/>
 
     <!--// Clean-up -->
diff --git a/QtVsTools.Package/Editors/Editor.QtDesigner.cs b/QtVsTools.Package/Editors/Editor.QtDesigner.cs
index cddc7fa5..b6cee8a6 100644
--- a/QtVsTools.Package/Editors/Editor.QtDesigner.cs
+++ b/QtVsTools.Package/Editors/Editor.QtDesigner.cs
@@ -81,13 +81,11 @@ namespace QtVsTools.Editors
                     var latestWriteTime = File.GetLastWriteTime(filePath);
                     if (lastWriteTime != latestWriteTime) {
                         lastWriteTime = latestWriteTime;
-                        await QtProjectIntellisense.RefreshAsync(
-                            project, projectPath, selectedFiles: itemId);
+                        await QtProjectIntellisense.RefreshAsync(project, projectPath);
                     }
                 }
                 if (lastWriteTime != File.GetLastWriteTime(filePath)) {
-                    await QtProjectIntellisense.RefreshAsync(
-                        project, projectPath, selectedFiles: itemId);
+                    await QtProjectIntellisense.RefreshAsync(project, projectPath);
                 }
             });
         }
diff --git a/QtVsTools.Package/Package/DteEventsHandler.cs b/QtVsTools.Package/Package/DteEventsHandler.cs
index 30ca31c0..b5cfdfc1 100644
--- a/QtVsTools.Package/Package/DteEventsHandler.cs
+++ b/QtVsTools.Package/Package/DteEventsHandler.cs
@@ -185,8 +185,10 @@ namespace QtVsTools
             if (debugStartWithoutDebuggingEvents != null)
                 debugStartWithoutDebuggingEvents.BeforeExecute -= debugStartWithoutDebuggingEvents_BeforeExecute;
 
-            if (vcProjectEngineEvents != null)
+            if (vcProjectEngineEvents != null) {
                 vcProjectEngineEvents.ItemPropertyChange -= OnVCProjectEngineItemPropertyChange;
+                vcProjectEngineEvents.ItemPropertyChange2 -= OnVCProjectEngineItemPropertyChange2;
+            }
 
             if (windowEvents != null)
                 windowEvents.WindowActivated -= WindowEvents_WindowActivated;
@@ -520,6 +522,7 @@ namespace QtVsTools
                 if (vcProjectEngineEvents != null) {
                     try {
                         vcProjectEngineEvents.ItemPropertyChange += OnVCProjectEngineItemPropertyChange;
+                        vcProjectEngineEvents.ItemPropertyChange2 += OnVCProjectEngineItemPropertyChange2;
                     } catch {
                         Messages.DisplayErrorMessage("VCProjectEngine events could not be registered.");
                     }
@@ -590,6 +593,23 @@ namespace QtVsTools
             }
         }
 
+        private void OnVCProjectEngineItemPropertyChange2(
+            object item,
+            string propertySheet,
+            string itemType,
+            string propertyName)
+        {
+            ThreadHelper.ThrowIfNotOnUIThread();
+            if (!propertyName.StartsWith("Qt") || propertyName == "QtLastBackgroundBuild")
+                return;
+            if (item is VCConfiguration vcConfig
+                && vcConfig.project is VCProject vcProject
+                && vcProject.Object is Project project) {
+                QtProjectIntellisense.Refresh(
+                    QtProjectTracker.Get(project, project.FullName).Project, vcConfig.Name);
+            }
+        }
+
         private static VCFile GetVCFileFromProject(string absFileName, VCProject project)
         {
             foreach (VCFile f in (IVCCollection)project.Files) {
diff --git a/QtVsTools.Package/QtMsBuild/QtProjectBuild.cs b/QtVsTools.Package/QtMsBuild/QtProjectBuild.cs
index 59049a1a..d893fe64 100644
--- a/QtVsTools.Package/QtMsBuild/QtProjectBuild.cs
+++ b/QtVsTools.Package/QtMsBuild/QtProjectBuild.cs
@@ -48,11 +48,18 @@ namespace QtVsTools.QtMsBuild
     using Common;
     using Core;
     using VisualStudio;
+    using static Common.EnumExt;
 
     class QtProjectBuild : Concurrent<QtProjectBuild>
     {
         static LazyFactory StaticLazy { get; } = new LazyFactory();
 
+        public enum Target
+        {
+            // Mark project as dirty, but do not request a build
+            [String("QtVsTools.QtMsBuild.QtProjectBuild.Target.SetOutdated")] SetOutdated
+        }
+
         static PunisherQueue<QtProjectBuild> BuildQueue => StaticLazy.Get(() =>
             BuildQueue, () => new PunisherQueue<QtProjectBuild>(
                 getItemKey: (QtProjectBuild build) =>
@@ -148,6 +155,35 @@ namespace QtVsTools.QtMsBuild
                 .Forget();
         }
 
+        public static void SetOutdated(
+            EnvDTE.Project project,
+            string projectPath,
+            string configName,
+            LoggerVerbosity verbosity = LoggerVerbosity.Quiet)
+        {
+            if (project == null)
+                throw new ArgumentException("Project cannot be null.");
+            if (configName == null)
+                throw new ArgumentException("Configuration name cannot be null.");
+
+            _ = Task.Run(() => SetOutdatedAsync(project, projectPath, configName, verbosity));
+        }
+
+        public static async Task SetOutdatedAsync(
+            EnvDTE.Project project,
+            string projectPath,
+            string configName,
+            LoggerVerbosity verbosity = LoggerVerbosity.Quiet)
+        {
+            await StartBuildAsync(
+                project,
+                projectPath,
+                configName,
+                null,
+                new[] { Target.SetOutdated.Cast<string>() },
+                verbosity);
+        }
+
         public static void Reset()
         {
             BuildQueue.Clear();
@@ -208,6 +244,12 @@ namespace QtVsTools.QtMsBuild
         {
             var msBuildProject = await writeAccess.GetProjectAsync(ConfiguredProject);
 
+            if (Targets.Any(t => t == Target.SetOutdated.Cast<string>())) {
+                msBuildProject.MarkDirty();
+                await writeAccess.ReleaseAsync();
+                return true;
+            }
+
             var solutionPath = QtProjectTracker.SolutionPath;
             var configProps = new Dictionary<string, string>(
                 ConfiguredProject.ProjectConfiguration.Dimensions.ToImmutableDictionary())
diff --git a/QtVsTools.Package/QtMsBuild/QtProjectIntelliSense.cs b/QtVsTools.Package/QtMsBuild/QtProjectIntelliSense.cs
index 101b51af..2597e22f 100644
--- a/QtVsTools.Package/QtMsBuild/QtProjectIntelliSense.cs
+++ b/QtVsTools.Package/QtMsBuild/QtProjectIntelliSense.cs
@@ -60,14 +60,15 @@ namespace QtVsTools.QtMsBuild
                     (configId != null) ? configId : "(all configs)", project.FullName));
             }
             string projectPath = project.FullName;
-            _ = Task.Run(() => RefreshAsync(project, projectPath, configId, selectedFiles));
+            _ = Task.Run(() => RefreshAsync(project, projectPath, configId, selectedFiles, false));
         }
 
         public static async Task RefreshAsync(
             EnvDTE.Project project,
             string projectPath,
             string configId = null,
-            IEnumerable<string> selectedFiles = null)
+            IEnumerable<string> selectedFiles = null,
+            bool refreshQtVars = false)
         {
             if (project == null || !QtProjectTracker.IsTracked(projectPath))
                 return;
@@ -92,9 +93,14 @@ namespace QtVsTools.QtMsBuild
             }
 
             foreach (var config in configs) {
-                await QtProjectBuild.StartBuildAsync(
-                    project, projectPath, config, properties, targets,
-                    LoggerVerbosity.Quiet);
+                if (refreshQtVars) {
+                    await QtProjectBuild.StartBuildAsync(
+                        project, projectPath, config, properties, targets,
+                        LoggerVerbosity.Quiet);
+                } else {
+                    await QtProjectBuild.SetOutdatedAsync(
+                        project, projectPath, config, LoggerVerbosity.Quiet);
+                }
             }
         }
     }
diff --git a/QtVsTools.Package/QtMsBuild/QtProjectTracker.cs b/QtVsTools.Package/QtMsBuild/QtProjectTracker.cs
index 01e3156f..464322e8 100644
--- a/QtVsTools.Package/QtMsBuild/QtProjectTracker.cs
+++ b/QtVsTools.Package/QtMsBuild/QtProjectTracker.cs
@@ -75,51 +75,11 @@ namespace QtVsTools.QtMsBuild
             Initialized = new EventWaitHandle(false, EventResetMode.ManualReset);
         }
 
-        class Subscriber : IDisposable
-        {
-            public Subscriber(QtProjectTracker tracker, ConfiguredProject config)
-            {
-                Tracker = tracker;
-                Config = config;
-                Subscription = Config.Services.ProjectSubscription.JointRuleSource.SourceBlock
-                    .LinkTo(new SubscriberAction(ProjectUpdateAsync),
-                        ruleNames: new[]
-                        {
-                            "ClCompile",
-                            "QtRule10_Settings",
-                            "QtRule30_Moc",
-                            "QtRule40_Rcc",
-                            "QtRule60_Repc",
-                            "QtRule50_Uic",
-                            "QtRule_Translation",
-                            "QtRule70_Deploy",
-                        },
-                        initialDataAsNew: false
-                    );
-            }
-
-            QtProjectTracker Tracker { get; }
-            ConfiguredProject Config { get; }
-            IDisposable Subscription { get; set; }
-
-            public void Dispose()
-            {
-                Subscription?.Dispose();
-                Subscription = null;
-            }
-
-            async Task ProjectUpdateAsync(IProjectVersionedValue<IProjectSubscriptionUpdate> update)
-            {
-                await Tracker.OnProjectUpdateAsync(Config, update.Value);
-            }
-        }
-
         public EnvDTE.Project Project { get; private set; }
         public string ProjectPath { get; private set; }
         public VCProject VcProject { get; private set; }
         public UnconfiguredProject UnconfiguredProject { get; private set; }
         public EventWaitHandle Initialized { get; }
-        List<Subscriber> Subscribers { get; set; }
 
         public static bool IsTracked(string projectPath)
         {
@@ -221,13 +181,11 @@ namespace QtVsTools.QtMsBuild
 
             Initialized.Set();
 
-            Subscribers = new List<Subscriber>();
             int n = configs.Count;
             int d = (100 - p) / (n * 2);
             foreach (var config in configs) {
                 var configProject = await UnconfiguredProject.LoadConfiguredProjectAsync(config);
                 UpdateInitStatus(p += d);
-                Subscribers.Add(new Subscriber(this, configProject));
                 configProject.ProjectUnloading += OnProjectUnloadingAsync;
                 if (QtVsToolsPackage.Instance.Options.BuildDebugInformation) {
                     Messages.Print(string.Format(
@@ -239,37 +197,6 @@ namespace QtVsTools.QtMsBuild
             }
         }
 
-
-        async Task OnProjectUpdateAsync(ConfiguredProject config, IProjectSubscriptionUpdate update)
-        {
-            var changes = update.ProjectChanges.Values
-                .Where(x => x.Difference.AnyChanges)
-                .Select(x => x.Difference);
-            var changesCount = changes
-                .Select(x => x.AddedItems.Count
-                    + x.ChangedItems.Count
-                    + x.ChangedProperties.Count
-                    + x.RemovedItems.Count
-                    + x.RenamedItems.Count)
-                .Sum();
-            var changedProps = changes.SelectMany(x => x.ChangedProperties);
-            if (changesCount == 0
-                || (changesCount == 1
-                    && changedProps.Count() == 1
-                    && changedProps.First() == "QtLastBackgroundBuild")) {
-                return;
-            }
-
-            if (QtVsToolsPackage.Instance.Options.BuildDebugInformation) {
-                Messages.Print(string.Format(
-                    "{0:HH:mm:ss.FFF} QtProjectTracker({1}): Changed [{2}] {3}",
-                    DateTime.Now, Thread.CurrentThread.ManagedThreadId,
-                    config.ProjectConfiguration.Name,
-                    config.UnconfiguredProject.FullPath));
-            }
-            await QtProjectIntellisense.RefreshAsync(Project, config.ProjectConfiguration.Name);
-        }
-
         async Task OnProjectUnloadingAsync(object sender, EventArgs args)
         {
             var project = sender as ConfiguredProject;
@@ -283,11 +210,6 @@ namespace QtVsTools.QtMsBuild
                     project.UnconfiguredProject.FullPath));
             }
             lock (CriticalSection) {
-                if (Subscribers != null) {
-                    Subscribers.ForEach(s => s.Dispose());
-                    Subscribers.Clear();
-                    Subscribers = null;
-                }
                 project.ProjectUnloading -= OnProjectUnloadingAsync;
                 Instances.TryRemove(project.UnconfiguredProject.FullPath, out QtProjectTracker _);
             }