ProjectExplorer: Use setup function for CustomToolChain

Change-Id: I05eeaad0914285c31928e9fad126b27ad78a0fa6
Reviewed-by: Jarek Kobus <jaroslaw.kobus@qt.io>

src/plugins/projectexplorer/customtoolchain.cpp

@@ -13,6 +13,7 @@
 #include "projectexplorerconstants.h"
 #include "projectexplorertr.h"
 #include "projectmacro.h"
+#include "toolchain.h"
 #include "toolchainconfigwidget.h"
 
 #include <utils/algorithm.h>
@@ -555,17 +556,24 @@ std::unique_ptr<ToolchainConfigWidget> CustomToolChain::createConfigurationWidge
     return std::make_unique<CustomToolChainConfigWidget>(this);
 }
 
-// --------------------------------------------------------------------------
 // CustomToolChainFactory
-// --------------------------------------------------------------------------
 
-CustomToolchainFactory::CustomToolchainFactory()
+class CustomToolchainFactory final : public ToolchainFactory
 {
+public:
+    CustomToolchainFactory()
+    {
         setDisplayName(Tr::tr("Custom"));
         setSupportedToolchainType(Constants::CUSTOM_TOOLCHAIN_TYPEID);
         setSupportsAllLanguages(true);
         setToolchainConstructor([] { return new CustomToolChain; });
         setUserCreatable(true);
+    }
+};
+
+void setupCustomToolchain()
+{
+    static CustomToolchainFactory theCustomToolchainFactory;
 }
 
 } // ProjectExplorer::Internal

src/plugins/projectexplorer/customtoolchain.h

@@ -3,14 +3,8 @@
 
 #pragma once
 
-#include "toolchain.h"
-
 namespace ProjectExplorer::Internal {
 
-class CustomToolchainFactory : public ToolchainFactory
-{
-public:
-    CustomToolchainFactory();
-};
+void setupCustomToolchain();
 
 } // ProjectExplorer::Interna;

src/plugins/projectexplorer/projectexplorer.cpp

@@ -647,8 +647,6 @@ public:
     WinDebugInterface m_winDebugInterface;
 #endif
 
-    CustomToolchainFactory m_customToolChainFactory;
-
     DesktopDeviceFactory m_desktopDeviceFactory;
 
     ToolChainOptionsPage m_toolChainOptionsPage;
@@ -818,6 +816,7 @@ bool ProjectExplorerPlugin::initialize(const QStringList &arguments, QString *er
     setupGccToolchains();
     setupMsvcToolchain();
     setupClangClToolchain();
+    setupCustomToolchain();
 
     setupProjectTreeWidgetFactory();