QtSupport: Split QtVersionFactory::create()

... into a 'canCreate()' and the actual creation, which can be
done by the already registered m_creator.

Simpler interface, with the (temporary) regression that the
EmbeddedLinuxQtVersion get constructed twice, once only to
determine that it should be alive afterwards. Will be fixed later.

Change-Id: I5da2cafe473b25a0207bbd628632c9a259780361
Reviewed-by: Christian Kandeler <christian.kandeler@qt.io>

14 files changed, 45 insertions, 56 deletions

diff --git a/src/plugins/android/androidqtversionfactory.cpp b/src/plugins/android/androidqtversionfactory.cpp
index 358f73583a..52082d1af5 100644
--- a/src/plugins/android/androidqtversionfactory.cpp
+++ b/src/plugins/android/androidqtversionfactory.cpp
@@ -40,14 +40,14 @@ AndroidQtVersionFactory::AndroidQtVersionFactory()
     setPriority(90);
 }
 
-QtSupport::BaseQtVersion *AndroidQtVersionFactory::create(ProFileEvaluator *evaluator)
+bool AndroidQtVersionFactory::canCreate(ProFileEvaluator *evaluator) const
 {
-    if (!evaluator->values(QLatin1String("CONFIG")).contains(QLatin1String("android"))
-            && evaluator->value(QLatin1String("QMAKE_PLATFORM")) != QLatin1String("android"))
-        return nullptr;
-    if (evaluator->values(QLatin1String("CONFIG")).contains(QLatin1String("android-no-sdk")))
-        return nullptr;
-    return new AndroidQtVersion;
+    if (!evaluator->values("CONFIG").contains("android")
+            && evaluator->value("QMAKE_PLATFORM") != "android")
+        return false;
+    if (evaluator->values("CONFIG").contains("android-no-sdk"))
+        return false;
+    return true;
 }
 
 } // Internal
diff --git a/src/plugins/android/androidqtversionfactory.h b/src/plugins/android/androidqtversionfactory.h
index 5c9d0f5893..b630bf3919 100644
--- a/src/plugins/android/androidqtversionfactory.h
+++ b/src/plugins/android/androidqtversionfactory.h
@@ -35,7 +35,7 @@ class AndroidQtVersionFactory : public QtSupport::QtVersionFactory
 public:
     AndroidQtVersionFactory();
 
-    QtSupport::BaseQtVersion *create(ProFileEvaluator *evaluator) override;
+    bool canCreate(ProFileEvaluator *evaluator) const override;
 };
 
 } // namespace Internal
diff --git a/src/plugins/ios/iosqtversionfactory.cpp b/src/plugins/ios/iosqtversionfactory.cpp
index ebdbd74c5a..8d118fe29c 100644
--- a/src/plugins/ios/iosqtversionfactory.cpp
+++ b/src/plugins/ios/iosqtversionfactory.cpp
@@ -39,11 +39,9 @@ IosQtVersionFactory::IosQtVersionFactory()
     setPriority(90);
 }
 
-QtSupport::BaseQtVersion *IosQtVersionFactory::create(ProFileEvaluator *evaluator)
+bool IosQtVersionFactory::canCreate(ProFileEvaluator *evaluator) const
 {
-    if (!(evaluator->values(QLatin1String("QMAKE_PLATFORM")).contains(QLatin1String("ios"))))
-        return nullptr;
-    return new IosQtVersion;
+    return evaluator->values("QMAKE_PLATFORM").contains("ios");
 }
 
 } // Internal
diff --git a/src/plugins/ios/iosqtversionfactory.h b/src/plugins/ios/iosqtversionfactory.h
index ce912ed60f..6bb18fd176 100644
--- a/src/plugins/ios/iosqtversionfactory.h
+++ b/src/plugins/ios/iosqtversionfactory.h
@@ -35,7 +35,7 @@ class IosQtVersionFactory : public QtSupport::QtVersionFactory
 public:
     IosQtVersionFactory();
 
-    QtSupport::BaseQtVersion *create(ProFileEvaluator *evaluator) override;
+    bool canCreate(ProFileEvaluator *evaluator) const override;
 };
 
 } // namespace Internal
diff --git a/src/plugins/qnx/qnxqtversionfactory.cpp b/src/plugins/qnx/qnxqtversionfactory.cpp
index eea7f49243..ad484ddc04 100644
--- a/src/plugins/qnx/qnxqtversionfactory.cpp
+++ b/src/plugins/qnx/qnxqtversionfactory.cpp
@@ -40,10 +40,7 @@ QnxQtVersionFactory::QnxQtVersionFactory()
     setPriority(50);
 }
 
-QtSupport::BaseQtVersion *QnxQtVersionFactory::create(ProFileEvaluator *evaluator)
+bool QnxQtVersionFactory::canCreate(ProFileEvaluator *evaluator) const
 {
-    if (evaluator->contains(QLatin1String("QNX_CPUDIR")))
-        return new QnxQtVersion;
-
-    return nullptr;
+    return evaluator->contains("QNX_CPUDIR");
 }
diff --git a/src/plugins/qnx/qnxqtversionfactory.h b/src/plugins/qnx/qnxqtversionfactory.h
index 5c3aabb520..4abdeaf31b 100644
--- a/src/plugins/qnx/qnxqtversionfactory.h
+++ b/src/plugins/qnx/qnxqtversionfactory.h
@@ -35,7 +35,7 @@ class QnxQtVersionFactory : public QtSupport::QtVersionFactory
 public:
     QnxQtVersionFactory();
 
-    QtSupport::BaseQtVersion *create(ProFileEvaluator *evaluator) override;
+    bool canCreate(ProFileEvaluator *evaluator) const override;
 };
 
 } // namespace Internal
diff --git a/src/plugins/qtsupport/desktopqtversionfactory.cpp b/src/plugins/qtsupport/desktopqtversionfactory.cpp
index 368fef9026..b7a8bcea90 100644
--- a/src/plugins/qtsupport/desktopqtversionfactory.cpp
+++ b/src/plugins/qtsupport/desktopqtversionfactory.cpp
@@ -35,11 +35,5 @@ DesktopQtVersionFactory::DesktopQtVersionFactory()
     setQtVersionCreator([] { return new DesktopQtVersion; });
     setSupportedType(Constants::DESKTOPQT);
     setPriority(0); // Lowest of all, we want to be the fallback
-}
-
-BaseQtVersion *DesktopQtVersionFactory::create(ProFileEvaluator *evaluator)
-{
-    Q_UNUSED(evaluator);
-    // we are the fallback :) so we don't care what kind of qt it is
-    return new DesktopQtVersion;
+    // No further restrictions. We are the fallback :) so we don't care what kind of qt it is.
 }
diff --git a/src/plugins/qtsupport/desktopqtversionfactory.h b/src/plugins/qtsupport/desktopqtversionfactory.h
index d2d12e2f95..00d308456e 100644
--- a/src/plugins/qtsupport/desktopqtversionfactory.h
+++ b/src/plugins/qtsupport/desktopqtversionfactory.h
@@ -34,8 +34,6 @@ class DesktopQtVersionFactory : public QtVersionFactory
 {
 public:
     DesktopQtVersionFactory();
-
-    BaseQtVersion *create(ProFileEvaluator *evaluator) override;
 };
 
 } // Internal
diff --git a/src/plugins/qtsupport/qtversionfactory.cpp b/src/plugins/qtsupport/qtversionfactory.cpp
index 4a00a199be..99c5e62478 100644
--- a/src/plugins/qtsupport/qtversionfactory.cpp
+++ b/src/plugins/qtsupport/qtversionfactory.cpp
@@ -71,6 +71,18 @@ BaseQtVersion *QtVersionFactory::restore(const QString &type, const QVariantMap
     return version;
 }
 
+BaseQtVersion *QtVersionFactory::create() const
+{
+    QTC_ASSERT(m_creator, return nullptr);
+    return m_creator();
+}
+
+bool QtVersionFactory::canCreate(ProFileEvaluator *evaluator) const
+{
+    Q_UNUSED(evaluator);
+    return true;
+}
+
 BaseQtVersion *QtVersionFactory::createQtVersionFromQMakePath(const Utils::FileName &qmakePath, bool isAutoDetected, const QString &autoDetectionSource, QString *error)
 {
     QHash<ProKey, ProString> versionInfo;
@@ -98,7 +110,9 @@ BaseQtVersion *QtVersionFactory::createQtVersionFromQMakePath(const Utils::FileN
         return nullptr;
 
     foreach (QtVersionFactory *factory, factories) {
-        if (BaseQtVersion *ver = factory->create(&evaluator)) {
+        if (factory->canCreate(&evaluator)) {
+            BaseQtVersion *ver = factory->create();
+            QTC_ASSERT(ver, continue);
             ver->setupQmakePathAndId(qmakePath);
             ver->setAutoDetectionSource(autoDetectionSource);
             ver->setIsAutodetected(isAutoDetected);
diff --git a/src/plugins/qtsupport/qtversionfactory.h b/src/plugins/qtsupport/qtversionfactory.h
index c66a87a740..59c8545157 100644
--- a/src/plugins/qtsupport/qtversionfactory.h
+++ b/src/plugins/qtsupport/qtversionfactory.h
@@ -54,7 +54,9 @@ public:
     /// a qtversion, the priority of the desktop factory is 0 and
     /// the desktop factory claims to handle all paths
     int priority() const { return m_priority; }
-    virtual BaseQtVersion *create(ProFileEvaluator *evaluator) = 0;
+
+    BaseQtVersion *create() const;
+    virtual bool canCreate(ProFileEvaluator *evaluator) const;
 
     static BaseQtVersion *createQtVersionFromQMakePath(
             const Utils::FileName &qmakePath, bool isAutoDetected = false,
diff --git a/src/plugins/remotelinux/embeddedlinuxqtversionfactory.cpp b/src/plugins/remotelinux/embeddedlinuxqtversionfactory.cpp
index 74b7bd106a..1ff52d2960 100644
--- a/src/plugins/remotelinux/embeddedlinuxqtversionfactory.cpp
+++ b/src/plugins/remotelinux/embeddedlinuxqtversionfactory.cpp
@@ -40,21 +40,17 @@ EmbeddedLinuxQtVersionFactory::EmbeddedLinuxQtVersionFactory()
     setPriority(10);
 }
 
-QtSupport::BaseQtVersion *EmbeddedLinuxQtVersionFactory::create(ProFileEvaluator *evaluator)
+bool EmbeddedLinuxQtVersionFactory::canCreate(ProFileEvaluator *evaluator) const
 {
     Q_UNUSED(evaluator);
 
-    auto version = new EmbeddedLinuxQtVersion;
+    EmbeddedLinuxQtVersion tempVersion;
+    QList<ProjectExplorer::Abi> abis = tempVersion.qtAbis();
 
-    QList<ProjectExplorer::Abi> abis = version->qtAbis();
     // Note: This fails for e.g. intel/meego cross builds on x86 linux machines.
-    if (abis.count() == 1
+    return  abis.count() == 1
             && abis.at(0).os() == ProjectExplorer::Abi::LinuxOS
-            && !ProjectExplorer::Abi::hostAbi().isCompatibleWith(abis.at(0)))
-        return version;
-
-    delete version;
-    return nullptr;
+            && !ProjectExplorer::Abi::hostAbi().isCompatibleWith(abis.at(0));
 }
 
 } // namespace Internal
diff --git a/src/plugins/remotelinux/embeddedlinuxqtversionfactory.h b/src/plugins/remotelinux/embeddedlinuxqtversionfactory.h
index 7e341acb2f..11dbdf6480 100644
--- a/src/plugins/remotelinux/embeddedlinuxqtversionfactory.h
+++ b/src/plugins/remotelinux/embeddedlinuxqtversionfactory.h
@@ -35,7 +35,7 @@ class EmbeddedLinuxQtVersionFactory : public QtSupport::QtVersionFactory
 public:
     EmbeddedLinuxQtVersionFactory();
 
-    QtSupport::BaseQtVersion *create(ProFileEvaluator *evaluator) override;
+    bool canCreate(ProFileEvaluator *evaluator) const override;
 };
 
 } // Internal
diff --git a/src/plugins/winrt/winrtqtversionfactory.cpp b/src/plugins/winrt/winrtqtversionfactory.cpp
index 38ebe45ba8..c8fe397000 100644
--- a/src/plugins/winrt/winrtqtversionfactory.cpp
+++ b/src/plugins/winrt/winrtqtversionfactory.cpp
@@ -40,14 +40,9 @@ WinRtQtVersionFactory::WinRtQtVersionFactory()
     setPriority(10);
 }
 
-QtSupport::BaseQtVersion *WinRtQtVersionFactory::create(ProFileEvaluator *evaluator)
+bool WinRtQtVersionFactory::canCreate(ProFileEvaluator *evaluator) const
 {
-    foreach (const QString &value, evaluator->values(QLatin1String("QMAKE_PLATFORM"))) {
-        if (value == QStringLiteral("winrt"))
-            return new WinRtQtVersion;
-    }
-
-    return nullptr;
+    return evaluator->values("QMAKE_PLATFORM").contains("winrt");
 }
 
 
@@ -59,14 +54,9 @@ WinRtPhoneQtVersionFactory::WinRtPhoneQtVersionFactory()
     setPriority(10);
 }
 
-QtSupport::BaseQtVersion *WinRtPhoneQtVersionFactory::create(ProFileEvaluator *evaluator)
+bool WinRtPhoneQtVersionFactory::canCreate(ProFileEvaluator *evaluator) const
 {
-    foreach (const QString &value, evaluator->values(QLatin1String("QMAKE_PLATFORM"))) {
-        if (value == QStringLiteral("winphone"))
-            return new WinRtPhoneQtVersion;
-    }
-
-    return nullptr;
+    return evaluator->values("QMAKE_PLATFORM").contains("winphone");
 }
 
 } // Internal
diff --git a/src/plugins/winrt/winrtqtversionfactory.h b/src/plugins/winrt/winrtqtversionfactory.h
index 1b778ff003..302a3ecf8d 100644
--- a/src/plugins/winrt/winrtqtversionfactory.h
+++ b/src/plugins/winrt/winrtqtversionfactory.h
@@ -35,7 +35,7 @@ class WinRtQtVersionFactory : public QtSupport::QtVersionFactory
 public:
     WinRtQtVersionFactory();
 
-    QtSupport::BaseQtVersion *create(ProFileEvaluator *evaluator) override;
+    bool canCreate(ProFileEvaluator *evaluator) const override;
 };
 
 class WinRtPhoneQtVersionFactory : public QtSupport::QtVersionFactory
@@ -43,7 +43,7 @@ class WinRtPhoneQtVersionFactory : public QtSupport::QtVersionFactory
 public:
     WinRtPhoneQtVersionFactory();
 
-    QtSupport::BaseQtVersion *create(ProFileEvaluator *evaluator) override;
+    bool canCreate(ProFileEvaluator *evaluator) const override;
 };
 
 } // Internal