CppTools: Optionally move raw project parts creation into thread

... by letting callers pass in a generator function.
This takes some load off the UI thread for larger projects.
For now only used by the QbsProjectManager, which can provide a thread-
safe generator function due to the project data existing in "value"
form.

Task-number: QTCREATORBUG-18533
Change-Id: I525dea36a4c4079bd1bd5a4fff844617547d56f1
Reviewed-by: hjk <hjk@qt.io>

src/plugins/cpptools/cppprojectupdater.cpp

@@ -61,7 +61,10 @@ void CppProjectUpdater::update(const ProjectExplorer::ProjectUpdateInfo &project
 
     // Run the project info generator in a worker thread and continue if that one is finished.
     const QFuture<ProjectInfo> future = Utils::runAsync([=]() {
-        Internal::ProjectInfoGenerator generator(m_futureInterface, projectUpdateInfo);
+        ProjectUpdateInfo fullProjectUpdateInfo = projectUpdateInfo;
+        if (fullProjectUpdateInfo.rppGenerator)
+            fullProjectUpdateInfo.rawProjectParts = fullProjectUpdateInfo.rppGenerator();
+        Internal::ProjectInfoGenerator generator(m_futureInterface, fullProjectUpdateInfo);
         return generator.generate();
     });
     m_generateFutureWatcher.setFuture(future);

src/plugins/projectexplorer/rawprojectpart.cpp

@@ -192,9 +192,11 @@ ToolChainInfo::ToolChainInfo(const ToolChain *toolChain,
 ProjectUpdateInfo::ProjectUpdateInfo(Project *project,
                                      const KitInfo &kitInfo,
                                      const Utils::Environment &env,
-                                     const RawProjectParts &rawProjectParts)
+                                     const RawProjectParts &rawProjectParts,
+                                     const RppGenerator &rppGenerator)
     : project(project)
     , rawProjectParts(rawProjectParts)
+    , rppGenerator(rppGenerator)
     , cToolChain(kitInfo.cToolChain)
     , cxxToolChain(kitInfo.cxxToolChain)
     , cToolChainInfo(ToolChainInfo(cToolChain, kitInfo.sysRootPath, env))

src/plugins/projectexplorer/rawprojectpart.h

@@ -163,16 +163,20 @@ public:
 class PROJECTEXPLORER_EXPORT ProjectUpdateInfo
 {
 public:
+    using RppGenerator = std::function<RawProjectParts()>;
+
     ProjectUpdateInfo() = default;
     ProjectUpdateInfo(Project *project,
                       const KitInfo &kitInfo,
                       const Utils::Environment &env,
-                      const RawProjectParts &rawProjectParts);
+                      const RawProjectParts &rawProjectParts,
+                      const RppGenerator &rppGenerator = {});
     bool isValid() const;
 
 public:
     QPointer<Project> project;
     RawProjectParts rawProjectParts;
+    RppGenerator rppGenerator;
 
     const ToolChain *cToolChain = nullptr;
     const ToolChain *cxxToolChain = nullptr;

src/plugins/qbsprojectmanager/qbsproject.cpp

@@ -810,16 +810,13 @@ static void getExpandedCompilerFlags(QStringList &cFlags, QStringList &cxxFlags,
     }
 }
 
-void QbsBuildSystem::updateCppCodeModel()
+static RawProjectParts generateProjectParts(
+        const QJsonObject &projectData,
+        const std::shared_ptr<const ToolChain> &cToolChain,
+        const std::shared_ptr<const ToolChain> &cxxToolChain,
+        QtVersion qtVersion
+        )
 {
-    OpTimer optimer("updateCppCodeModel");
-    const QJsonObject projectData = session()->projectData();
-    if (projectData.isEmpty())
-        return;
-
-    const QtSupport::CppKitInfo kitInfo(kit());
-    QTC_ASSERT(kitInfo.isValid(), return);
-
     RawProjectParts rpps;
     forAllProducts(projectData, [&](const QJsonObject &prd) {
         const QString productName = prd.value("full-display-name").toString();
@@ -843,7 +840,7 @@ void QbsBuildSystem::updateCppCodeModel()
         const Utils::QtVersion qtVersionForPart
             = prd.value("module-properties").toObject().value("Qt.core.version").isUndefined()
                   ? Utils::QtVersion::None
-                  : kitInfo.projectPartQtVersion;
+                  : qtVersion;
 
         const QJsonArray groups = prd.value("groups").toArray();
         for (const QJsonValue &g : groups) {
@@ -860,8 +857,8 @@ void QbsBuildSystem::updateCppCodeModel()
             QStringList cFlags;
             QStringList cxxFlags;
             getExpandedCompilerFlags(cFlags, cxxFlags, props);
-            rpp.setFlagsForC({kitInfo.cToolChain, cFlags});
+            rpp.setFlagsForC({cToolChain.get(), cFlags});
-            rpp.setFlagsForCxx({kitInfo.cxxToolChain, cxxFlags});
+            rpp.setFlagsForCxx({cxxToolChain.get(), cxxFlags});
 
             rpp.setMacros(transform<QVector>(arrayToStringList(props.value("cpp.defines")),
                     [](const QString &s) { return Macro::fromKeyValue(s); }));
@@ -946,8 +943,28 @@ void QbsBuildSystem::updateCppCodeModel()
             rpps.append(rpp);
         }
     });
+    return rpps;
+}
 
-    m_cppCodeModelUpdater->update({project(), kitInfo, activeParseEnvironment(), rpps});
+void QbsBuildSystem::updateCppCodeModel()
+{
+    OpTimer optimer("updateCppCodeModel");
+    const QJsonObject projectData = session()->projectData();
+    if (projectData.isEmpty())
+        return;
+
+    const QtSupport::CppKitInfo kitInfo(kit());
+    QTC_ASSERT(kitInfo.isValid(), return);
+    const auto cToolchain = std::shared_ptr<ToolChain>(kitInfo.cToolChain
+            ? kitInfo.cToolChain->clone() : nullptr);
+    const auto cxxToolchain = std::shared_ptr<ToolChain>(kitInfo.cxxToolChain
+            ? kitInfo.cxxToolChain->clone() : nullptr);
+
+    m_cppCodeModelUpdater->update({project(), kitInfo, activeParseEnvironment(), {},
+            [projectData, kitInfo, cToolchain, cxxToolchain] {
+                    return generateProjectParts(projectData, cToolchain, cxxToolchain,
+                                                kitInfo.projectPartQtVersion);
+    }});
 }
 
 void QbsBuildSystem::updateExtraCompilers()