qmake: Fix issues with executing system calls

Do not try to reuse the QFutureInterface that is used for the parsing
process. Reusing the QFutureInterface can lead to issues. So far no
problems were triggered, but a30aa4421a0257b048197b51330e6bf5c2732af5
introduced a watcher that tells the qmake parser to ignore all system
calls after the future was canceled. This was somehow, sometimes
triggered on the reused QFutureInterface even though the user didn't
cancel anyhing, leading to all system calls to bail out in the
subsequent run.

Using a new QFutureInterface instance for each parsing run solves the
issue.

Amends a30aa4421a0257b048197b51330e6bf5c2732af5

Fixes: QTCREATORBUG-25970
Change-Id: I6836c97038c36968e93815c6121bc284edbe19bb
Reviewed-by: Christian Kandeler <christian.kandeler@qt.io>

2 files changed, 22 insertions, 14 deletions

diff --git a/src/plugins/qmakeprojectmanager/qmakeproject.cpp b/src/plugins/qmakeprojectmanager/qmakeproject.cpp
index 387c0688a4..f62398a315 100644
--- a/src/plugins/qmakeprojectmanager/qmakeproject.cpp
+++ b/src/plugins/qmakeprojectmanager/qmakeproject.cpp
@@ -284,8 +284,11 @@ QmakeBuildSystem::~QmakeBuildSystem()
     delete m_qmakeVfs;
     m_qmakeVfs = nullptr;
 
-    m_asyncUpdateFutureInterface.reportCanceled();
-    m_asyncUpdateFutureInterface.reportFinished();
+    if (m_asyncUpdateFutureInterface) {
+        m_asyncUpdateFutureInterface->reportCanceled();
+        m_asyncUpdateFutureInterface->reportFinished();
+        m_asyncUpdateFutureInterface.reset();
+    }
 }
 
 void QmakeBuildSystem::updateCodeModels()
@@ -592,8 +595,9 @@ void QmakeBuildSystem::incrementPendingEvaluateFutures()
     }
     ++m_pendingEvaluateFuturesCount;
     TRACE("pending inc to: " << m_pendingEvaluateFuturesCount);
-    m_asyncUpdateFutureInterface.setProgressRange(m_asyncUpdateFutureInterface.progressMinimum(),
-                                                  m_asyncUpdateFutureInterface.progressMaximum() + 1);
+    m_asyncUpdateFutureInterface->setProgressRange(m_asyncUpdateFutureInterface->progressMinimum(),
+                                                   m_asyncUpdateFutureInterface->progressMaximum()
+                                                       + 1);
 }
 
 void QmakeBuildSystem::decrementPendingEvaluateFutures()
@@ -606,15 +610,17 @@ void QmakeBuildSystem::decrementPendingEvaluateFutures()
         return; // We are closing the project!
     }
 
-    m_asyncUpdateFutureInterface.setProgressValue(m_asyncUpdateFutureInterface.progressValue() + 1);
+    m_asyncUpdateFutureInterface->setProgressValue(m_asyncUpdateFutureInterface->progressValue()
+                                                   + 1);
     if (m_pendingEvaluateFuturesCount == 0) {
         // We are done!
         setRootProjectNode(QmakeNodeTreeBuilder::buildTree(this));
 
         if (!m_rootProFile->validParse())
-            m_asyncUpdateFutureInterface.reportCanceled();
+            m_asyncUpdateFutureInterface->reportCanceled();
 
-        m_asyncUpdateFutureInterface.reportFinished();
+        m_asyncUpdateFutureInterface->reportFinished();
+        m_asyncUpdateFutureInterface.reset();
         m_cancelEvaluate = false;
 
         // TODO clear the profile cache ?
@@ -660,12 +666,13 @@ void QmakeBuildSystem::asyncUpdate()
         m_qmakeVfs->invalidateCache();
     }
 
-    m_asyncUpdateFutureInterface.setProgressRange(0, 0);
-    Core::ProgressManager::addTask(m_asyncUpdateFutureInterface.future(),
+    m_asyncUpdateFutureInterface.reset(new QFutureInterface<void>);
+    m_asyncUpdateFutureInterface->setProgressRange(0, 0);
+    Core::ProgressManager::addTask(m_asyncUpdateFutureInterface->future(),
                                    tr("Reading Project \"%1\"").arg(project()->displayName()),
                                    Constants::PROFILE_EVALUATE);
 
-    m_asyncUpdateFutureInterface.reportStarted();
+    m_asyncUpdateFutureInterface->reportStarted();
     const auto watcher = new QFutureWatcher<void>(this);
     connect(watcher, &QFutureWatcher<void>::canceled, this, [this, watcher] {
         if (!m_qmakeGlobals)
@@ -677,7 +684,7 @@ void QmakeBuildSystem::asyncUpdate()
         watcher->disconnect();
         watcher->deleteLater();
     });
-    watcher->setFuture(m_asyncUpdateFutureInterface.future());
+    watcher->setFuture(m_asyncUpdateFutureInterface->future());
 
     const Kit *const k = kit();
     QtSupport::BaseQtVersion *const qtVersion = QtSupport::QtKitAspect::qtVersion(k);
@@ -688,8 +695,9 @@ void QmakeBuildSystem::asyncUpdate()
                       .arg(project()->displayName(), k->displayName())
                 : tr("Cannot parse project \"%1\": No kit selected.").arg(project()->displayName());
         proFileParseError(errorMessage, project()->projectFilePath());
-        m_asyncUpdateFutureInterface.reportCanceled();
-        m_asyncUpdateFutureInterface.reportFinished();
+        m_asyncUpdateFutureInterface->reportCanceled();
+        m_asyncUpdateFutureInterface->reportFinished();
+        m_asyncUpdateFutureInterface.reset();
         return;
     }
 
diff --git a/src/plugins/qmakeprojectmanager/qmakeproject.h b/src/plugins/qmakeprojectmanager/qmakeproject.h
index fba8c8db7a..89397407ab 100644
--- a/src/plugins/qmakeprojectmanager/qmakeproject.h
+++ b/src/plugins/qmakeprojectmanager/qmakeproject.h
@@ -198,7 +198,7 @@ private:
 
     QString m_qmakeSysroot;
 
-    QFutureInterface<void> m_asyncUpdateFutureInterface;
+    std::unique_ptr<QFutureInterface<void>> m_asyncUpdateFutureInterface;
     int m_pendingEvaluateFuturesCount = 0;
     AsyncUpdateState m_asyncUpdateState = Base;
     bool m_cancelEvaluate = false;