diff --git a/src/libs/utils/porting.h b/src/libs/utils/porting.h
index 30db1eb8924..ca0faa4e78e 100644
--- a/src/libs/utils/porting.h
+++ b/src/libs/utils/porting.h
@@ -38,9 +38,9 @@ constexpr Qt::SplitBehaviorFlags SkipEmptyParts = Qt::SkipEmptyParts;
 #endif
 
 #if QT_VERSION < QT_VERSION_CHECK(6, 0, 0)
-using QHashSeedType = uint;
+using QHashValueType = uint;
 #else
-using QHashSeedType = size_t;
+using QHashValueType = size_t;
 #endif
 
 } // namespace Utils
diff --git a/src/plugins/android/androidconfigurations.cpp b/src/plugins/android/androidconfigurations.cpp
index cd120b54360..0f3c35840e9 100644
--- a/src/plugins/android/androidconfigurations.cpp
+++ b/src/plugins/android/androidconfigurations.cpp
@@ -545,7 +545,8 @@ FilePath AndroidConfig::gdbPath(const ProjectExplorer::Abi &abi, const BaseQtVer
 FilePath AndroidConfig::gdbPathFromNdk(const Abi &abi, const FilePath &ndkLocation) const
 {
     const FilePath path = ndkLocation.pathAppended(
-        QString("prebuilt/%1/bin/gdb%2").arg(toolchainHostFromNdk(ndkLocation), QTC_HOST_EXE_SUFFIX));
+        QString("prebuilt/%1/bin/gdb%2").arg(toolchainHostFromNdk(ndkLocation),
+                                             QString(QTC_HOST_EXE_SUFFIX)));
     if (path.exists())
         return path;
     // fallback for old NDKs (e.g. 10e)
@@ -553,7 +554,7 @@ FilePath AndroidConfig::gdbPathFromNdk(const Abi &abi, const FilePath &ndkLocati
                                                    .arg(toolchainPrefix(abi),
                                                         toolchainHostFromNdk(ndkLocation),
                                                         toolsPrefix(abi),
-                                                        QTC_HOST_EXE_SUFFIX));
+                                                        QString(QTC_HOST_EXE_SUFFIX)));
 }
 
 FilePath AndroidConfig::makePath(const BaseQtVersion *qtVersion) const
@@ -564,7 +565,8 @@ FilePath AndroidConfig::makePath(const BaseQtVersion *qtVersion) const
 FilePath AndroidConfig::makePathFromNdk(const FilePath &ndkLocation) const
 {
     return ndkLocation.pathAppended(
-                QString("prebuilt/%1/bin/make%2").arg(toolchainHostFromNdk(ndkLocation), QTC_HOST_EXE_SUFFIX));
+                QString("prebuilt/%1/bin/make%2").arg(toolchainHostFromNdk(ndkLocation),
+                                                      QString(QTC_HOST_EXE_SUFFIX)));
 }
 
 FilePath AndroidConfig::openJDKBinPath() const
diff --git a/src/plugins/android/androidsettingswidget.cpp b/src/plugins/android/androidsettingswidget.cpp
index 7587b4ea465..68efdbd0b44 100644
--- a/src/plugins/android/androidsettingswidget.cpp
+++ b/src/plugins/android/androidsettingswidget.cpp
@@ -57,6 +57,7 @@
 #include <QMessageBox>
 #include <QModelIndex>
 #include <QSettings>
+#include <QStandardPaths>
 #include <QString>
 #include <QTimer>
 #include <QUrl>
diff --git a/src/plugins/classview/classviewsymbollocation.cpp b/src/plugins/classview/classviewsymbollocation.cpp
index 67d56eabf04..d8b241c333b 100644
--- a/src/plugins/classview/classviewsymbollocation.cpp
+++ b/src/plugins/classview/classviewsymbollocation.cpp
@@ -54,7 +54,11 @@ SymbolLocation::SymbolLocation(QString file, int lineNumber, int columnNumber) :
         m_column = 0;
 
     // pre-computate hash value
+#if QT_VERSION >= QT_VERSION_CHECK(6, 0, 0)
+    m_hash = qHashMulti(0, m_fileName, m_line, m_column);
+#else
     m_hash = qHash(qMakePair(m_fileName, qMakePair(m_line, m_column)));
+#endif
 }
 
 } // namespace Internal
diff --git a/src/plugins/classview/classviewsymbollocation.h b/src/plugins/classview/classviewsymbollocation.h
index 144c0227cd7..a97d5ac03ca 100644
--- a/src/plugins/classview/classviewsymbollocation.h
+++ b/src/plugins/classview/classviewsymbollocation.h
@@ -25,6 +25,8 @@
 
 #pragma once
 
+#include <utils/porting.h>
+
 #include <QMetaType>
 #include <QString>
 
@@ -43,7 +45,7 @@ public:
     inline const QString &fileName() const { return m_fileName; }
     inline int line() const { return m_line; }
     inline int column() const { return m_column; }
-    inline int hash() const { return m_hash; }
+    inline Utils::QHashValueType hash() const { return m_hash; }
     inline bool operator==(const SymbolLocation &other) const
     {
         return line() == other.line() && column() == other.column()
@@ -54,11 +56,11 @@ private:
     QString m_fileName; //!< file name
     int m_line;         //!< line number
     int m_column;       //!< column
-    int m_hash;         //!< precalculated hash value for the object, to speed up qHash
+    Utils::QHashValueType m_hash;   //!< precalculated hash value for the object, to speed up qHash
 };
 
 //! qHash overload for QHash/QSet
-inline uint qHash(const SymbolLocation &location)
+inline Utils::QHashValueType qHash(const ClassView::Internal::SymbolLocation &location)
 {
     return location.hash();
 }
diff --git a/src/plugins/coreplugin/menubarfilter.cpp b/src/plugins/coreplugin/menubarfilter.cpp
index 2a23bb4cda7..308d1e30ed9 100644
--- a/src/plugins/coreplugin/menubarfilter.cpp
+++ b/src/plugins/coreplugin/menubarfilter.cpp
@@ -42,7 +42,7 @@
 #include <QTimer>
 
 QT_BEGIN_NAMESPACE
-uint qHash(const QPointer<QAction> &p, Utils::QHashSeedType seed)
+Utils::QHashValueType qHash(const QPointer<QAction> &p, Utils::QHashValueType seed)
 {
     return qHash(p.data(), seed);
 }
diff --git a/src/plugins/cppcheck/cppcheckmanualrundialog.cpp b/src/plugins/cppcheck/cppcheckmanualrundialog.cpp
index 47a3feb195b..a9cb1789808 100644
--- a/src/plugins/cppcheck/cppcheckmanualrundialog.cpp
+++ b/src/plugins/cppcheck/cppcheckmanualrundialog.cpp
@@ -81,7 +81,7 @@ ManualRunDialog::ManualRunDialog(const CppcheckOptions &options,
     layout->addWidget(buttons);
 
     if (auto layout = m_options->layout())
-        layout->setMargin(0);
+        layout->setContentsMargins(0, 0, 0, 0);
 
     m_options->load(options);
 }
diff --git a/src/plugins/ios/iosbuildconfiguration.cpp b/src/plugins/ios/iosbuildconfiguration.cpp
index d3f61f30032..5cb7742c31c 100644
--- a/src/plugins/ios/iosbuildconfiguration.cpp
+++ b/src/plugins/ios/iosbuildconfiguration.cpp
@@ -363,7 +363,8 @@ void IosBuildSettingsWidget::updateWarningText()
             auto profile = IosConfigurations::provisioningProfile(identifier);
             if (profile && QDateTime::currentDateTimeUtc() > profile->expirationDate()) {
                warningText = IosBuildConfiguration::tr("Provisioning profile expired. Expiration date: %1")
-                       .arg(profile->expirationDate().toLocalTime().toString(Qt::SystemLocaleLongDate));
+                       .arg(QLocale::system().toString(profile->expirationDate().toLocalTime(),
+                                                       QLocale::LongFormat));
             }
         }
     }
diff --git a/src/plugins/ios/iosconfigurations.cpp b/src/plugins/ios/iosconfigurations.cpp
index b7b5e942751..4007f06a35b 100644
--- a/src/plugins/ios/iosconfigurations.cpp
+++ b/src/plugins/ios/iosconfigurations.cpp
@@ -650,7 +650,7 @@ QString ProvisioningProfile::displayName() const
 QString ProvisioningProfile::details() const
 {
     return tr("Team: %1\nApp ID: %2\nExpiration date: %3").arg(m_team->identifier()).arg(m_appID)
-            .arg(m_expirationDate.toLocalTime().toString(Qt::SystemLocaleShortDate));
+            .arg(QLocale::system().toString(m_expirationDate.toLocalTime(), QLocale::ShortFormat));
 }
 
 QDebug &operator<<(QDebug &stream, std::shared_ptr<ProvisioningProfile> profile)
diff --git a/src/plugins/qmljseditor/qmljseditor.h b/src/plugins/qmljseditor/qmljseditor.h
index 50b25c2d283..58a1894c02d 100644
--- a/src/plugins/qmljseditor/qmljseditor.h
+++ b/src/plugins/qmljseditor/qmljseditor.h
@@ -27,6 +27,7 @@
 
 #include "qmljseditor_global.h"
 
+#include <qmljs/parser/qmljsast_p.h>
 #include <qmljs/qmljsscanner.h>
 #include <qmljstools/qmljssemanticinfo.h>
 #include <texteditor/texteditor.h>
@@ -41,10 +42,7 @@ QT_BEGIN_NAMESPACE
 class QComboBox;
 QT_END_NAMESPACE
 
-namespace QmlJS {
-    class ModelManagerInterface;
-namespace AST { class UiObjectMember; }
-}
+namespace QmlJS { class ModelManagerInterface; }
 
 namespace QmlJSEditor {
 
diff --git a/src/tools/clangbackend/source/diagnostic.h b/src/tools/clangbackend/source/diagnostic.h
index 49161fe40e1..a71ac5afa82 100644
--- a/src/tools/clangbackend/source/diagnostic.h
+++ b/src/tools/clangbackend/source/diagnostic.h
@@ -27,6 +27,8 @@
 
 #include <clangsupport_global.h>
 
+#include <QVector>
+
 #include <clang-c/Index.h>
 
 #include <functional>