QbsProjectManager: Cache run environment

Setting up the qbs run environment is not free, and the respective code
gets triggered from other plugins much more often than expected.

Task-number: QTCREATORBUG-20175
Change-Id: I6529718d20738140963486caef103d6d17958d50
Reviewed-by: Christian Stenger <christian.stenger@qt.io>

src/plugins/qbsprojectmanager/qbsproject.cpp

@@ -452,6 +452,7 @@ void QbsProject::updateAfterParse()
     updateCppCodeModel();
     updateQmlJsCodeModel();
     emit fileListChanged();
+    emit dataChanged();
 }
 
 void QbsProject::delayedUpdateAfterParse()
@@ -609,6 +610,7 @@ void QbsProject::updateAfterBuild()
         m_extraCompilersPending = false;
         updateCppCodeModel();
     }
+    emit dataChanged();
 }
 
 void QbsProject::registerQbsProjectParser(QbsProjectParser *p)

src/plugins/qbsprojectmanager/qbsproject.h

@@ -107,6 +107,9 @@ public:
 
     void delayParsing();
 
+signals:
+    void dataChanged();
+
 private:
     void handleQbsParsingDone(bool success);
 

src/plugins/qbsprojectmanager/qbsrunconfiguration.cpp

@@ -109,6 +109,7 @@ QbsRunConfiguration::QbsRunConfiguration(Target *target)
         if (success && !terminalAspect->isUserSet())
             terminalAspect->setUseTerminal(isConsoleApplication());
     });
+    connect(project, &QbsProject::dataChanged, this, [this] { m_envCache.clear(); });
     connect(BuildManager::instance(), &BuildManager::buildStateChanged, this,
             [this, project](Project *p) {
                 if (p == project && !BuildManager::isBuilding(p)) {
@@ -255,6 +256,12 @@ QString QbsRunConfiguration::baseWorkingDirectory() const
 
 void QbsRunConfiguration::addToBaseEnvironment(Utils::Environment &env) const
 {
+    const auto key = qMakePair(env.toStringList(), m_usingLibraryPaths);
+    const auto it = m_envCache.constFind(key);
+    if (it != m_envCache.constEnd()) {
+        env = it.value();
+        return;
+    }
     QbsProject *project = static_cast<QbsProject *>(target()->project());
     if (project && project->qbsProject().isValid()) {
         const qbs::ProductData product = findProduct(project->qbsProjectData(), uniqueProductName());
@@ -279,6 +286,7 @@ void QbsRunConfiguration::addToBaseEnvironment(Utils::Environment &env) const
             }
         }
     }
+    m_envCache.insert(key, env);
 }
 
 QString QbsRunConfiguration::buildSystemTarget() const

src/plugins/qbsprojectmanager/qbsrunconfiguration.h

@@ -28,7 +28,9 @@
 #include <projectexplorer/runnables.h>
 
 #include <QCheckBox>
+#include <QHash>
 #include <QLabel>
+#include <QPair>
 #include <QStringList>
 #include <QWidget>
 
@@ -83,6 +85,9 @@ private:
 
     void updateTarget();
 
+    using EnvCache = QHash<QPair<QStringList, bool>, Utils::Environment>;
+    mutable EnvCache m_envCache;
+
     QbsInstallStep *m_currentInstallStep = nullptr; // We do not take ownership!
     ProjectExplorer::BuildStepList *m_currentBuildStepList = nullptr; // We do not take ownership!
     QString m_uniqueProductName;