ProjectExplorer: Fix potential race condition

When using BuildStep::runImpl() it was possible for the async part
to still be running while the BuildStep is already deleted.

This change returns the Future so that users can wait for it to finish.

Change-Id: I27c0fc8741c59851c5ab8f5cb858fbcda923c14d
Reviewed-by: Jarek Kobus <jaroslaw.kobus@qt.io>
Reviewed-by: <github-actions-qt-creator@cristianadam.eu>

src/plugins/android/androiddeployqtstep.cpp

@@ -488,7 +488,7 @@ void AndroidDeployQtStep::gatherFilesToPull()
 
 void AndroidDeployQtStep::doRun()
 {
-    runInThread([this] { return runImpl(); });
+    m_synchronizer.addFuture(runInThread([this] { return runImpl(); }));
 }
 
 void AndroidDeployQtStep::runCommand(const CommandLine &command)

src/plugins/android/androiddeployqtstep.h

@@ -12,6 +12,7 @@
 
 #include <utils/commandline.h>
 #include <utils/environment.h>
+#include <utils/futuresynchronizer.h>
 
 namespace Utils { class QtcProcess; }
 
@@ -91,6 +92,8 @@ private:
     Utils::FilePath m_workingDirectory;
     Utils::Environment m_environment;
     AndroidDeviceInfo m_deviceInfo;
+
+    Utils::FutureSynchronizer m_synchronizer;
 };
 
 }

src/plugins/projectexplorer/buildstep.cpp

@@ -295,7 +295,7 @@ QVariant BuildStep::data(Id id) const
     immutable steps are run. The default implementation returns \c false.
 */
 
-void BuildStep::runInThread(const std::function<bool()> &syncImpl)
+QFuture<bool> BuildStep::runInThread(const std::function<bool()> &syncImpl)
 {
     m_runInGuiThread = false;
     m_cancelFlag = false;
@@ -304,7 +304,9 @@ void BuildStep::runInThread(const std::function<bool()> &syncImpl)
         emit finished(watcher->result());
         watcher->deleteLater();
     });
-    watcher->setFuture(Utils::runAsync(syncImpl));
+    auto future = Utils::runAsync(syncImpl);
+    watcher->setFuture(future);
+    return future;
 }
 
 std::function<bool ()> BuildStep::cancelChecker() const

src/plugins/projectexplorer/buildstep.h

@@ -10,6 +10,7 @@
 
 #include <utils/qtcassert.h>
 
+#include <QFuture>
 #include <QWidget>
 
 #include <atomic>
@@ -117,7 +118,7 @@ signals:
 protected:
     virtual QWidget *createConfigWidget();
 
-    void runInThread(const std::function<bool()> &syncImpl);
+    QFuture<bool> runInThread(const std::function<bool()> &syncImpl);
 
     std::function<bool()> cancelChecker() const;
     bool isCanceled() const;

src/plugins/remotelinux/tarpackagecreationstep.cpp

@@ -13,6 +13,8 @@
 #include <projectexplorer/project.h>
 #include <projectexplorer/target.h>
 
+#include <utils/futuresynchronizer.h>
+
 #include <QDateTime>
 #include <QDir>
 #include <QFile>
@@ -80,6 +82,8 @@ private:
     BoolAspect *m_ignoreMissingFilesAspect = nullptr;
     bool m_packagingNeeded = false;
     QList<DeployableFile> m_files;
+
+    FutureSynchronizer m_synchronizer;
 };
 
 TarPackageCreationStep::TarPackageCreationStep(BuildStepList *bsl, Id id)
@@ -126,7 +130,7 @@ bool TarPackageCreationStep::init()
 
 void TarPackageCreationStep::doRun()
 {
-    runInThread([this] { return runImpl(); });
+    m_synchronizer.addFuture(runInThread([this] { return runImpl(); }));
 }
 
 bool TarPackageCreationStep::fromMap(const QVariantMap &map)