diff --git a/src/libs/3rdparty/cplusplus/ASTPatternBuilder.h b/src/libs/3rdparty/cplusplus/ASTPatternBuilder.h
index f3934b7ba1c..9270a3429ca 100644
--- a/src/libs/3rdparty/cplusplus/ASTPatternBuilder.h
+++ b/src/libs/3rdparty/cplusplus/ASTPatternBuilder.h
@@ -26,8 +26,7 @@
 // Changes will be lost.
 //
 
-#ifndef CPLUSPLUS_AST_PATTERN_BUILDER_H
-#define CPLUSPLUS_AST_PATTERN_BUILDER_H
+#pragma once
 
 #include "CPlusPlusForwardDeclarations.h"
 #include "AST.h"
@@ -1385,5 +1384,3 @@ public:
 };
 
 } // end of namespace CPlusPlus
-
-#endif // CPLUSPLUS_AST_PATTERN_BUILDER_H
diff --git a/src/plugins/diffeditor/diffeditordocument.cpp b/src/plugins/diffeditor/diffeditordocument.cpp
index 9928ef61972..aac0ba2f063 100644
--- a/src/plugins/diffeditor/diffeditordocument.cpp
+++ b/src/plugins/diffeditor/diffeditordocument.cpp
@@ -203,11 +203,19 @@ QString DiffEditorDocument::fallbackSaveAsPath() const
     return QDir::homePath();
 }
 
+bool DiffEditorDocument::isSaveAsAllowed() const
+{
+    return !isReloading();
+}
+
 bool DiffEditorDocument::save(QString *errorString, const QString &fileName, bool autoSave)
 {
     Q_UNUSED(errorString)
     Q_UNUSED(autoSave)
 
+    if (isReloading())
+        return false;
+
     const bool ok = write(fileName, format(), plainText(), errorString);
 
     if (!ok)
@@ -330,6 +338,7 @@ void DiffEditorDocument::beginReload()
 {
     emit aboutToReload();
     m_isReloading = true;
+    emit changed();
     const bool blocked = blockSignals(true);
     setDiffFiles(QList<FileData>(), QString());
     setDescription(QString());
@@ -339,6 +348,7 @@ void DiffEditorDocument::beginReload()
 void DiffEditorDocument::endReload(bool success)
 {
     m_isReloading = false;
+    emit changed();
     emit reloadFinished(success);
 }
 
diff --git a/src/plugins/diffeditor/diffeditordocument.h b/src/plugins/diffeditor/diffeditordocument.h
index c61d17ad909..18c73b61cee 100644
--- a/src/plugins/diffeditor/diffeditordocument.h
+++ b/src/plugins/diffeditor/diffeditordocument.h
@@ -70,7 +70,7 @@ public:
     QString fallbackSaveAsPath() const override;
     QString fallbackSaveAsFileName() const override;
 
-    bool isSaveAsAllowed() const override { return true; }
+    bool isSaveAsAllowed() const override;
     bool save(QString *errorString, const QString &fileName, bool autoSave) override;
     void reload();
     bool reload(QString *errorString, ReloadFlag flag, ChangeType type) override;
diff --git a/src/plugins/projectexplorer/runconfiguration.cpp b/src/plugins/projectexplorer/runconfiguration.cpp
index 338681ce854..b51b238118b 100644
--- a/src/plugins/projectexplorer/runconfiguration.cpp
+++ b/src/plugins/projectexplorer/runconfiguration.cpp
@@ -538,6 +538,19 @@ IRunConfigurationAspect *IRunControlFactory::createRunConfigurationAspect(RunCon
     than it needs to be.
 */
 
+
+const char PRIORITY_KEY[] = "RunControlFactoryPriority";
+
+int ProjectExplorer::IRunControlFactory::priority() const
+{
+    return property(PRIORITY_KEY).toInt(); // 0 by default.
+}
+
+void IRunControlFactory::setPriority(int priority)
+{
+    setProperty(PRIORITY_KEY, priority);
+}
+
 namespace Internal {
 
 enum class RunWorkerState
diff --git a/src/plugins/projectexplorer/runconfiguration.h b/src/plugins/projectexplorer/runconfiguration.h
index 4d7f927f81b..891c17a57e4 100644
--- a/src/plugins/projectexplorer/runconfiguration.h
+++ b/src/plugins/projectexplorer/runconfiguration.h
@@ -341,6 +341,10 @@ public:
     virtual RunControl *create(RunConfiguration *runConfiguration, Core::Id runMode, QString *errorMessage);
 
     virtual IRunConfigurationAspect *createRunConfigurationAspect(RunConfiguration *rc);
+
+    int priority() const;
+protected:
+    void setPriority(int priority); // Higher values will be preferred.
 };
 
 class PROJECTEXPLORER_EXPORT RunConfigWidget : public QWidget
diff --git a/src/tools/cplusplus-update-frontend/cplusplus-update-frontend.cpp b/src/tools/cplusplus-update-frontend/cplusplus-update-frontend.cpp
index 9a5b7c67007..2b83d7fa4ea 100644
--- a/src/tools/cplusplus-update-frontend/cplusplus-update-frontend.cpp
+++ b/src/tools/cplusplus-update-frontend/cplusplus-update-frontend.cpp
@@ -1246,8 +1246,7 @@ void generateASTVisitor_H(const Snapshot &, const QDir &cplusplusDir,
   QTextStream out(&file);
   out << copyrightHeader <<
 "\n"
-"#ifndef CPLUSPLUS_ASTVISITOR_H\n"
-"#define CPLUSPLUS_ASTVISITOR_H\n"
+"#pragma once\n"
 "\n"
 "#include \"CPlusPlusForwardDeclarations.h\"\n"
 "#include \"ASTfwd.h\"\n"
@@ -1317,9 +1316,7 @@ void generateASTVisitor_H(const Snapshot &, const QDir &cplusplusDir,
 "   TranslationUnit *_translationUnit;\n"
 "};\n"
 "\n"
-"} // namespace CPlusPlus\n"
-"\n"
-"#endif // CPLUSPLUS_ASTVISITOR_H\n";
+"} // namespace CPlusPlus\n";
 
   closeAndPrintFilePath(file);
 }
@@ -1339,8 +1336,7 @@ void generateASTMatcher_H(const Snapshot &, const QDir &cplusplusDir,
   QTextStream out(&file);
   out << copyrightHeader <<
 "\n"
-"#ifndef ASTMATCHER_H\n"
-"#define ASTMATCHER_H\n"
+"#pragma once\n"
 "\n"
 "#include \"ASTfwd.h\"\n"
 "\n"
@@ -1360,9 +1356,7 @@ void generateASTMatcher_H(const Snapshot &, const QDir &cplusplusDir,
   out <<
 "};\n"
 "\n"
-"} // namespace CPlusPlus\n"
-"\n"
-"#endif // CPLUSPLUS_ASTMATCHER_H\n";
+"} // namespace CPlusPlus\n";
 
   closeAndPrintFilePath(file);
 }
@@ -1574,8 +1568,7 @@ void generateASTPatternBuilder_h(const QDir &cplusplusDir)
     out
             << copyrightHeader
             << generatedHeader
-            << "#ifndef CPLUSPLUS_AST_PATTERN_BUILDER_H" << endl
-            << "#define CPLUSPLUS_AST_PATTERN_BUILDER_H" << endl
+            << "#pragma once" << endl
             << endl
             << "#include \"CPlusPlusForwardDeclarations.h\"" << endl
             << "#include \"AST.h\"" << endl
@@ -1683,9 +1676,7 @@ void generateASTPatternBuilder_h(const QDir &cplusplusDir)
     out
             << "};" << endl
             << endl
-            << "} // end of namespace CPlusPlus" << endl
-            << endl
-            << "#endif // CPLUSPLUS_AST_PATTERN_BUILDER_H" << endl;
+            << "} // end of namespace CPlusPlus" << endl;
 
     closeAndPrintFilePath(file);
 }