diff --git a/doc/src/vcs/creator-vcs-git.qdoc b/doc/src/vcs/creator-vcs-git.qdoc
index f5cd4a2e922..54d58e96710 100644
--- a/doc/src/vcs/creator-vcs-git.qdoc
+++ b/doc/src/vcs/creator-vcs-git.qdoc
@@ -281,6 +281,17 @@
             \li Set the current branch to track the selected one.
     \endtable
 
+    \section3 Configuring Merge Tools
+
+    Only graphical merge tools are supported. You can configure the
+    merge tool to use on the command line. For example, to use the
+    \l{http://kdiff3.sourceforge.net/}{KDiff3} merge tool, enter the
+    following command:
+
+    \badcode
+    git config --global merge.tool kdiff3
+    \endcode
+
     \section2 Applying Patches
 
     Patches are rewriting instructions that can be applied to a set of files.
diff --git a/share/qtcreator/qml/qmlpuppet/qml2puppet/instances/objectnodeinstance.cpp b/share/qtcreator/qml/qmlpuppet/qml2puppet/instances/objectnodeinstance.cpp
index 3ee177a3872..18e36270ce5 100644
--- a/share/qtcreator/qml/qmlpuppet/qml2puppet/instances/objectnodeinstance.cpp
+++ b/share/qtcreator/qml/qmlpuppet/qml2puppet/instances/objectnodeinstance.cpp
@@ -685,7 +685,7 @@ static inline QString fixComponentPathForIncompatibleQt(const QString &component
     if (componentPath.contains(importString)) {
         int index = componentPath.indexOf(importString) + 8;
         const QString relativeImportPath = componentPath.right(componentPath.length() - index);
-        QString fixedComponentPath = QLibraryInfo::location(QLibraryInfo::ImportsPath) + relativeImportPath;
+        QString fixedComponentPath = QLibraryInfo::location(QLibraryInfo::Qml2ImportsPath) + relativeImportPath;
         fixedComponentPath.replace(QLatin1Char('\\'), QLatin1Char('/'));
         if (QFileInfo::exists(fixedComponentPath))
             return fixedComponentPath;
diff --git a/src/libs/3rdparty/cplusplus/Parser.cpp b/src/libs/3rdparty/cplusplus/Parser.cpp
index 05ac1102452..c2198b65783 100644
--- a/src/libs/3rdparty/cplusplus/Parser.cpp
+++ b/src/libs/3rdparty/cplusplus/Parser.cpp
@@ -1834,7 +1834,11 @@ bool Parser::parseEnumSpecifier(SpecifierListAST *&node)
             error(cursor(), "expected identifier before '%s'", tok().spell());
             return false;
         }
-        parseName(ast->name);
+
+        if (LA() == T_IDENTIFIER)
+            parseName(ast->name);
+        else
+            return false;
 
         if (_languageFeatures.cxx11Enabled && LA() == T_COLON) {
             ast->colon_token = consumeToken();
diff --git a/src/libs/clangsupport/processcreator.cpp b/src/libs/clangsupport/processcreator.cpp
index 22b52793e30..aa9ba9641a5 100644
--- a/src/libs/clangsupport/processcreator.cpp
+++ b/src/libs/clangsupport/processcreator.cpp
@@ -36,6 +36,13 @@ namespace ClangBackEnd {
 
 using namespace std::chrono_literals;
 
+static QProcess::ProcessChannelMode kProcessChannelMode
+#ifdef Q_OS_WIN
+    = QProcess::MergedChannels;
+#else
+    = QProcess::ForwardedChannels;
+#endif
+
 ProcessCreator::ProcessCreator()
 {
 }
@@ -66,7 +73,7 @@ std::future<QProcessUniquePointer> ProcessCreator::createProcess() const
     return std::async(std::launch::async, [&] {
         checkIfProcessPathExists();
         auto process = QProcessUniquePointer(new QProcess);
-        process->setProcessChannelMode(QProcess::QProcess::ForwardedChannels);
+        process->setProcessChannelMode(kProcessChannelMode);
         process->setProcessEnvironment(processEnvironment());
         process->start(m_processPath, m_arguments);
         process->waitForStarted(5000);
diff --git a/src/plugins/autotoolsprojectmanager/autotoolsproject.cpp b/src/plugins/autotoolsprojectmanager/autotoolsproject.cpp
index c211fcc471b..fc4850b84fc 100644
--- a/src/plugins/autotoolsprojectmanager/autotoolsproject.cpp
+++ b/src/plugins/autotoolsprojectmanager/autotoolsproject.cpp
@@ -276,10 +276,8 @@ void AutotoolsProject::updateCppCodeModel()
 
     CppTools::ProjectPart::QtVersion activeQtVersion = CppTools::ProjectPart::NoQt;
     if (QtSupport::BaseQtVersion *qtVersion = QtSupport::QtKitInformation::qtVersion(k)) {
-        if (qtVersion->qtVersion() <= QtSupport::QtVersionNumber(4,8,6))
-            activeQtVersion = CppTools::ProjectPart::Qt4_8_6AndOlder;
-        else if (qtVersion->qtVersion() < QtSupport::QtVersionNumber(5,0,0))
-            activeQtVersion = CppTools::ProjectPart::Qt4Latest;
+        if (qtVersion->qtVersion() < QtSupport::QtVersionNumber(5,0,0))
+            activeQtVersion = CppTools::ProjectPart::Qt4;
         else
             activeQtVersion = CppTools::ProjectPart::Qt5;
     }
diff --git a/src/plugins/clangcodemodel/clangassistproposalitem.cpp b/src/plugins/clangcodemodel/clangassistproposalitem.cpp
index 6b4d0b81629..ed15a006f66 100644
--- a/src/plugins/clangcodemodel/clangassistproposalitem.cpp
+++ b/src/plugins/clangcodemodel/clangassistproposalitem.cpp
@@ -210,11 +210,19 @@ void ClangAssistProposalItem::apply(TextDocumentManipulatorInterface &manipulato
 
             if (!abandonParen && ccr.completionKind == CodeCompletion::FunctionDefinitionCompletionKind) {
                 const CodeCompletionChunk resultType = ccr.chunks.first();
-                QTC_ASSERT(resultType.kind == CodeCompletionChunk::ResultType, return;);
-                if (::Utils::Text::matchPreviousWord(manipulator, cursor, resultType.text.toString())) {
-                    extraCharacters += methodDefinitionParameters(ccr.chunks);
-                    // To skip the next block.
-                    abandonParen = true;
+                if (resultType.kind == CodeCompletionChunk::ResultType) {
+                    if (::Utils::Text::matchPreviousWord(manipulator, cursor, resultType.text.toString())) {
+                        extraCharacters += methodDefinitionParameters(ccr.chunks);
+                        // To skip the next block.
+                        abandonParen = true;
+                    }
+                } else {
+                    // Do nothing becasue it's not a function definition.
+
+                    // It's a clang bug that the function might miss a ResultType chunk
+                    // when the base class method is called from the overriding method
+                    // of the derived class. For example:
+                    // void Derived::foo() override { Base::<complete here> }
                 }
             }
             if (!abandonParen) {
diff --git a/src/plugins/clangcodemodel/clangcompletionassistprocessor.cpp b/src/plugins/clangcodemodel/clangcompletionassistprocessor.cpp
index e87135351db..e8d7086662c 100644
--- a/src/plugins/clangcodemodel/clangcompletionassistprocessor.cpp
+++ b/src/plugins/clangcodemodel/clangcompletionassistprocessor.cpp
@@ -185,7 +185,7 @@ void ClangCompletionAssistProcessor::handleAvailableCompletions(const CodeComple
 {
     QTC_CHECK(m_completions.isEmpty());
 
-    if (m_sentRequestType == FunctionHintCompletion) {
+    if (m_sentRequestType == FunctionHintCompletion && !completions.isEmpty()) {
         const CodeCompletion &firstCompletion = completions.front();
         if (firstCompletion.completionKind == CodeCompletion::FunctionOverloadCompletionKind) {
             setAsyncProposalAvailable(createFunctionHintProposal(completions));
diff --git a/src/plugins/clangcodemodel/clangeditordocumentprocessor.cpp b/src/plugins/clangcodemodel/clangeditordocumentprocessor.cpp
index 706677d87ee..7a185bb8213 100644
--- a/src/plugins/clangcodemodel/clangeditordocumentprocessor.cpp
+++ b/src/plugins/clangcodemodel/clangeditordocumentprocessor.cpp
@@ -469,7 +469,7 @@ private:
         // Determine file kind with respect to ambiguous headers.
         CppTools::ProjectFile::Kind fileKind = CppTools::ProjectFile::classify(m_filePath);
         if (fileKind == CppTools::ProjectFile::AmbiguousHeader) {
-            fileKind = m_projectPart.languageVersion <= CppTools::ProjectPart::LatestCVersion
+            fileKind = m_projectPart.languageVersion <= ProjectExplorer::LanguageVersion::LatestC
                  ? CppTools::ProjectFile::CHeader
                  : CppTools::ProjectFile::CXXHeader;
         }
diff --git a/src/plugins/clangcodemodel/clanghoverhandler.cpp b/src/plugins/clangcodemodel/clanghoverhandler.cpp
index 158bb9db64f..3817f82f0ad 100644
--- a/src/plugins/clangcodemodel/clanghoverhandler.cpp
+++ b/src/plugins/clangcodemodel/clanghoverhandler.cpp
@@ -100,10 +100,6 @@ static QFuture<CppTools::ToolTipInfo> editorDocumentHandlesToolTipInfo(
     return QFuture<CppTools::ToolTipInfo>();
 }
 
-ClangHoverHandler::ClangHoverHandler()
-{
-}
-
 ClangHoverHandler::~ClangHoverHandler()
 {
     abort();
diff --git a/src/plugins/clangcodemodel/clanghoverhandler.h b/src/plugins/clangcodemodel/clanghoverhandler.h
index e6e262ecd01..7f7bdbb18dd 100644
--- a/src/plugins/clangcodemodel/clanghoverhandler.h
+++ b/src/plugins/clangcodemodel/clanghoverhandler.h
@@ -37,7 +37,6 @@ class ClangHoverHandler : public TextEditor::BaseHoverHandler
     Q_DECLARE_TR_FUNCTIONS(ClangHoverHandler)
 
 public:
-    ClangHoverHandler();
     ~ClangHoverHandler() override;
 
     void identifyMatch(TextEditor::TextEditorWidget *editorWidget,
diff --git a/src/plugins/clangcodemodel/clangutils.cpp b/src/plugins/clangcodemodel/clangutils.cpp
index 971c0551749..62c78f8c6d0 100644
--- a/src/plugins/clangcodemodel/clangutils.cpp
+++ b/src/plugins/clangcodemodel/clangutils.cpp
@@ -70,6 +70,7 @@ public:
         : CompilerOptionsBuilder(projectPart,
                                  UseSystemHeader::No,
                                  CppTools::SkipBuiltIn::No,
+                                 CppTools::SkipLanguageDefines::Yes,
                                  QString(CLANG_VERSION),
                                  QString(CLANG_RESOURCE_DIR))
     {
diff --git a/src/plugins/clangformat/clangformat.qbs b/src/plugins/clangformat/clangformat.qbs
index 9b575fc73ca..f470951e9d1 100644
--- a/src/plugins/clangformat/clangformat.qbs
+++ b/src/plugins/clangformat/clangformat.qbs
@@ -1,5 +1,4 @@
 import qbs
-import qbs.FileInfo
 
 QtcPlugin {
     name: "ClangFormat"
@@ -8,7 +7,6 @@ QtcPlugin {
     Depends { name: "TextEditor" }
     Depends { name: "CppTools" }
     Depends { name: "ProjectExplorer" }
-    Depends { name: "ExtensionSystem" }
     Depends { name: "Utils" }
 
     Depends { name: "libclang"; required: false }
diff --git a/src/plugins/clangtools/clangtoolruncontrol.cpp b/src/plugins/clangtools/clangtoolruncontrol.cpp
index 67d8c013e63..8423d6771cf 100644
--- a/src/plugins/clangtools/clangtoolruncontrol.cpp
+++ b/src/plugins/clangtools/clangtoolruncontrol.cpp
@@ -194,6 +194,7 @@ static AnalyzeUnits toAnalyzeUnits(const FileInfos &fileInfos)
         CompilerOptionsBuilder optionsBuilder(*fileInfo.projectPart,
                                               CppTools::UseSystemHeader::No,
                                               CppTools::SkipBuiltIn::No,
+                                              CppTools::SkipLanguageDefines::Yes,
                                               QString(CLANG_VERSION),
                                               QString(CLANG_RESOURCE_DIR));
         QStringList arguments = extraClangToolsPrependOptions();
diff --git a/src/plugins/clangtools/clangtools.qbs b/src/plugins/clangtools/clangtools.qbs
index 97759e54c5c..7eb7e6c7c70 100644
--- a/src/plugins/clangtools/clangtools.qbs
+++ b/src/plugins/clangtools/clangtools.qbs
@@ -8,7 +8,6 @@ QtcPlugin {
     Depends { name: "Core" }
     Depends { name: "TextEditor" }
     Depends { name: "CppTools" }
-    Depends { name: "ExtensionSystem" }
     Depends { name: "ProjectExplorer" }
     Depends { name: "QtcSsh" }
     Depends { name: "Utils" }
diff --git a/src/plugins/cmakeprojectmanager/cmakeproject.cpp b/src/plugins/cmakeprojectmanager/cmakeproject.cpp
index ddf9ba6d896..598a0f7b4a8 100644
--- a/src/plugins/cmakeprojectmanager/cmakeproject.cpp
+++ b/src/plugins/cmakeprojectmanager/cmakeproject.cpp
@@ -286,10 +286,8 @@ void CMakeProject::updateProjectData(CMakeBuildConfiguration *bc)
 
     CppTools::ProjectPart::QtVersion activeQtVersion = CppTools::ProjectPart::NoQt;
     if (QtSupport::BaseQtVersion *qtVersion = QtSupport::QtKitInformation::qtVersion(k)) {
-        if (qtVersion->qtVersion() <= QtSupport::QtVersionNumber(4,8,6))
-            activeQtVersion = CppTools::ProjectPart::Qt4_8_6AndOlder;
-        else if (qtVersion->qtVersion() < QtSupport::QtVersionNumber(5,0,0))
-            activeQtVersion = CppTools::ProjectPart::Qt4Latest;
+        if (qtVersion->qtVersion() < QtSupport::QtVersionNumber(5,0,0))
+            activeQtVersion = CppTools::ProjectPart::Qt4;
         else
             activeQtVersion = CppTools::ProjectPart::Qt5;
     }
diff --git a/src/plugins/compilationdatabaseprojectmanager/compilationdatabaseproject.cpp b/src/plugins/compilationdatabaseprojectmanager/compilationdatabaseproject.cpp
index 487652aeb94..47c66df91a5 100644
--- a/src/plugins/compilationdatabaseprojectmanager/compilationdatabaseproject.cpp
+++ b/src/plugins/compilationdatabaseprojectmanager/compilationdatabaseproject.cpp
@@ -253,7 +253,7 @@ CompilationDatabaseProject::CompilationDatabaseProject(const Utils::FileName &pr
             tcInfo.targetTriple = tc->originalTargetTriple();
             tcInfo.sysRootPath = ProjectExplorer::SysRootKitInformation::sysRoot(kit).toString();
             tcInfo.headerPathsRunner = tc->createBuiltInHeaderPathsRunner();
-            tcInfo.predefinedMacrosRunner = tc->createPredefinedMacrosRunner();
+            tcInfo.macroInspectionRunner = tc->createMacroInspectionRunner();
 
             m_cppCodeModelUpdater->update({this, tcInfo, tcInfo, rpps});
 
diff --git a/src/plugins/compilationdatabaseprojectmanager/compilationdatabaseprojectmanager.qbs b/src/plugins/compilationdatabaseprojectmanager/compilationdatabaseprojectmanager.qbs
new file mode 100644
index 00000000000..e21dc9e1230
--- /dev/null
+++ b/src/plugins/compilationdatabaseprojectmanager/compilationdatabaseprojectmanager.qbs
@@ -0,0 +1,19 @@
+import qbs
+
+QtcPlugin {
+    name: "CompilationDatabaseProjectManager"
+
+    Depends { name: "Core" }
+    Depends { name: "CppTools" }
+    Depends { name: "ProjectExplorer" }
+    Depends { name: "TextEditor" }
+    Depends { name: "Utils" }
+
+    files: [
+        "compilationdatabaseconstants.h",
+        "compilationdatabaseproject.cpp",
+        "compilationdatabaseproject.h",
+        "compilationdatabaseprojectmanagerplugin.cpp",
+        "compilationdatabaseprojectmanagerplugin.h",
+    ]
+}
diff --git a/src/plugins/coreplugin/find/findtoolwindow.cpp b/src/plugins/coreplugin/find/findtoolwindow.cpp
index 85897fb8ae8..04f138a1515 100644
--- a/src/plugins/coreplugin/find/findtoolwindow.cpp
+++ b/src/plugins/coreplugin/find/findtoolwindow.cpp
@@ -269,7 +269,7 @@ void FindToolWindow::acceptAndGetParameters(QString *term, IFindFilter **filter)
 {
     QTC_ASSERT(filter, return);
     *filter = nullptr;
-    Find::updateFindCompletion(m_ui.searchTerm->text());
+    Find::updateFindCompletion(m_ui.searchTerm->text(), Find::findFlags());
     int index = m_ui.filterList->currentIndex();
     QString searchTerm = m_ui.searchTerm->text();
     if (index >= 0)
diff --git a/src/plugins/coreplugin/menubarfilter.cpp b/src/plugins/coreplugin/menubarfilter.cpp
index 69c178ae94c..7791bb1f1ef 100644
--- a/src/plugins/coreplugin/menubarfilter.cpp
+++ b/src/plugins/coreplugin/menubarfilter.cpp
@@ -190,8 +190,6 @@ void Core::Internal::MenuBarFilter::prepareSearch(const QString &entry)
     const QStringList entryPath = normalized.split(separators.at(0), QString::SkipEmptyParts);
     m_entries.clear();
     QVector<const QMenu *> processedMenus;
-    for (QAction* action : menuBarActions()) {
-        requestMenuUpdate(action);
+    for (QAction* action : menuBarActions())
         m_entries << matchesForAction(action, entryPath, QStringList(), processedMenus);
-    }
 }
diff --git a/src/plugins/cppcheck/cppcheck.qbs b/src/plugins/cppcheck/cppcheck.qbs
index 56f6d737c10..9a113c2cf30 100644
--- a/src/plugins/cppcheck/cppcheck.qbs
+++ b/src/plugins/cppcheck/cppcheck.qbs
@@ -5,7 +5,6 @@ QtcPlugin {
 
     Depends { name: "Core" }
     Depends { name: "CppTools" }
-    Depends { name: "ExtensionSystem" }
     Depends { name: "ProjectExplorer" }
     Depends { name: "TextEditor" }
     Depends { name: "Utils" }
diff --git a/src/plugins/cppcheck/cppchecktool.cpp b/src/plugins/cppcheck/cppchecktool.cpp
index 28111cd3f6e..38d70be0894 100644
--- a/src/plugins/cppcheck/cppchecktool.cpp
+++ b/src/plugins/cppcheck/cppchecktool.cpp
@@ -137,7 +137,7 @@ QStringList CppcheckTool::additionalArguments(const CppTools::ProjectPart &part)
     if (!m_options.guessArguments)
         return result;
 
-    using Version = CppTools::ProjectPart::LanguageVersion;
+    using Version = ProjectExplorer::LanguageVersion;
     switch (part.languageVersion) {
     case Version::C89:
         result.push_back("--std=c89 --language=c");
@@ -148,6 +148,9 @@ QStringList CppcheckTool::additionalArguments(const CppTools::ProjectPart &part)
     case Version::C11:
         result.push_back("--std=c11 --language=c");
         break;
+    case Version::C18:
+        result.push_back("--language=c");
+        break;
     case Version::CXX03:
         result.push_back("--std=c++03 --language=c++");
         break;
@@ -159,6 +162,7 @@ QStringList CppcheckTool::additionalArguments(const CppTools::ProjectPart &part)
         break;
     case Version::CXX98:
     case Version::CXX17:
+    case Version::CXX2a:
         result.push_back("--language=c++");
         break;
     }
diff --git a/src/plugins/cpptools/compileroptionsbuilder.cpp b/src/plugins/cpptools/compileroptionsbuilder.cpp
index e722722e252..1dbcff2e030 100644
--- a/src/plugins/cpptools/compileroptionsbuilder.cpp
+++ b/src/plugins/cpptools/compileroptionsbuilder.cpp
@@ -44,13 +44,15 @@ namespace CppTools {
 CompilerOptionsBuilder::CompilerOptionsBuilder(const ProjectPart &projectPart,
                                                UseSystemHeader useSystemHeader,
                                                SkipBuiltIn skipBuiltInHeaderPathsAndDefines,
+                                               SkipLanguageDefines skipLanguageDefines,
                                                QString clangVersion,
                                                QString clangResourceDirectory)
     : m_projectPart(projectPart)
-    , m_useSystemHeader(useSystemHeader)
     , m_clangVersion(clangVersion)
     , m_clangResourceDirectory(clangResourceDirectory)
+    , m_useSystemHeader(useSystemHeader)
     , m_skipBuiltInHeaderPathsAndDefines(skipBuiltInHeaderPathsAndDefines)
+    , m_skipLanguageDefines(skipLanguageDefines)
 {
 }
 
@@ -59,7 +61,7 @@ QStringList CompilerOptionsBuilder::build(CppTools::ProjectFile::Kind fileKind,
     m_options.clear();
 
     if (fileKind == ProjectFile::CHeader || fileKind == ProjectFile::CSource) {
-        QTC_ASSERT(m_projectPart.languageVersion <= ProjectPart::LatestCVersion,
+        QTC_ASSERT(m_projectPart.languageVersion <= ProjectExplorer::LanguageVersion::LatestC,
                    return QStringList(););
     }
 
@@ -196,7 +198,7 @@ void CompilerOptionsBuilder::addExtraCodeModelFlags()
 
 void CompilerOptionsBuilder::enableExceptions()
 {
-    if (m_projectPart.languageVersion > ProjectPart::LatestCVersion)
+    if (m_projectPart.languageVersion > ProjectExplorer::LanguageVersion::LatestC)
         add(QLatin1String("-fcxx-exceptions"));
     add(QLatin1String("-fexceptions"));
 }
@@ -378,7 +380,8 @@ void CompilerOptionsBuilder::addMacros(const ProjectExplorer::Macros &macros)
 
 void CompilerOptionsBuilder::updateLanguageOption(ProjectFile::Kind fileKind)
 {
-    const bool objcExt = m_projectPart.languageExtensions & ProjectPart::ObjectiveCExtensions;
+    const bool objcExt = m_projectPart.languageExtensions
+                         & ProjectExplorer::LanguageExtension::ObjectiveC;
     const QStringList options = createLanguageOptionGcc(fileKind, objcExt);
     if (options.isEmpty())
         return;
@@ -394,41 +397,51 @@ void CompilerOptionsBuilder::updateLanguageOption(ProjectFile::Kind fileKind)
 
 void CompilerOptionsBuilder::addOptionsForLanguage(bool checkForBorlandExtensions)
 {
+    using ProjectExplorer::LanguageExtension;
+    using ProjectExplorer::LanguageVersion;
+
     QStringList opts;
-    const ProjectPart::LanguageExtensions languageExtensions = m_projectPart.languageExtensions;
-    const bool gnuExtensions = languageExtensions & ProjectPart::GnuExtensions;
+    const ProjectExplorer::LanguageExtensions languageExtensions = m_projectPart.languageExtensions;
+    const bool gnuExtensions = languageExtensions & LanguageExtension::Gnu;
 
     switch (m_projectPart.languageVersion) {
-    case ProjectPart::C89:
+    case LanguageVersion::C89:
         opts << (gnuExtensions ? QLatin1String("-std=gnu89") : QLatin1String("-std=c89"));
         break;
-    case ProjectPart::C99:
+    case LanguageVersion::C99:
         opts << (gnuExtensions ? QLatin1String("-std=gnu99") : QLatin1String("-std=c99"));
         break;
-    case ProjectPart::C11:
+    case LanguageVersion::C11:
         opts << (gnuExtensions ? QLatin1String("-std=gnu11") : QLatin1String("-std=c11"));
         break;
-    case ProjectPart::CXX11:
+    case LanguageVersion::C18:
+        // Clang 6, 7 and current trunk do not accept "gnu18"/"c18", so use the "*17" variants.
+        opts << (gnuExtensions ? QLatin1String("-std=gnu17") : QLatin1String("-std=c17"));
+        break;
+    case LanguageVersion::CXX11:
         opts << (gnuExtensions ? QLatin1String("-std=gnu++11") : QLatin1String("-std=c++11"));
         break;
-    case ProjectPart::CXX98:
+    case LanguageVersion::CXX98:
         opts << (gnuExtensions ? QLatin1String("-std=gnu++98") : QLatin1String("-std=c++98"));
         break;
-    case ProjectPart::CXX03:
+    case LanguageVersion::CXX03:
         opts << (gnuExtensions ? QLatin1String("-std=gnu++03") : QLatin1String("-std=c++03"));
         break;
-    case ProjectPart::CXX14:
+    case LanguageVersion::CXX14:
         opts << (gnuExtensions ? QLatin1String("-std=gnu++14") : QLatin1String("-std=c++14"));
         break;
-    case ProjectPart::CXX17:
+    case LanguageVersion::CXX17:
         opts << (gnuExtensions ? QLatin1String("-std=gnu++17") : QLatin1String("-std=c++17"));
         break;
+    case LanguageVersion::CXX2a:
+        opts << (gnuExtensions ? QLatin1String("-std=gnu++2a") : QLatin1String("-std=c++2a"));
+        break;
     }
 
-    if (languageExtensions & ProjectPart::MicrosoftExtensions)
+    if (languageExtensions & LanguageExtension::Microsoft)
         opts << QLatin1String("-fms-extensions");
 
-    if (checkForBorlandExtensions && (languageExtensions & ProjectPart::BorlandExtensions))
+    if (checkForBorlandExtensions && (languageExtensions & LanguageExtension::Borland))
         opts << QLatin1String("-fborland-extensions");
 
     m_options.append(opts);
@@ -588,6 +601,21 @@ QString CompilerOptionsBuilder::includeOption() const
 
 bool CompilerOptionsBuilder::excludeDefineDirective(const ProjectExplorer::Macro &macro) const
 {
+    // Avoid setting __cplusplus & co as this might conflict with other command line flags.
+    // Clang should set __cplusplus based on -std= and -fms-compatibility-version version.
+    static const auto languageDefines = {"__cplusplus",
+                                         "__STDC_VERSION__",
+                                         "_MSC_BUILD",
+                                         "_MSVC_LANG",
+                                         "_MSC_FULL_VER",
+                                         "_MSC_VER"};
+    if (m_skipLanguageDefines == SkipLanguageDefines::Yes
+            && std::find(languageDefines.begin(),
+                         languageDefines.end(),
+                         macro.key) != languageDefines.end()) {
+        return true;
+    }
+
     // Ignore for all compiler toolchains since LLVM has it's own implementation for
     // __has_include(STR) and __has_include_next(STR)
     if (macro.key.startsWith("__has_include"))
diff --git a/src/plugins/cpptools/compileroptionsbuilder.h b/src/plugins/cpptools/compileroptionsbuilder.h
index 1274c1b860c..67a7345a306 100644
--- a/src/plugins/cpptools/compileroptionsbuilder.h
+++ b/src/plugins/cpptools/compileroptionsbuilder.h
@@ -31,13 +31,19 @@
 
 namespace CppTools {
 
-enum class UseSystemHeader
+enum class UseSystemHeader : char
 {
     Yes,
     No
 };
 
-enum class SkipBuiltIn
+enum class SkipBuiltIn : char
+{
+    Yes,
+    No
+};
+
+enum class SkipLanguageDefines : char
 {
     Yes,
     No
@@ -54,6 +60,7 @@ public:
     CompilerOptionsBuilder(const ProjectPart &projectPart,
                            UseSystemHeader useSystemHeader = UseSystemHeader::No,
                            SkipBuiltIn skipBuiltInHeaderPathsAndDefines = SkipBuiltIn::No,
+                           SkipLanguageDefines skipLanguageDefines = SkipLanguageDefines::Yes,
                            QString clangVersion = QString(),
                            QString clangResourceDirectory = QString());
 
@@ -107,12 +114,13 @@ private:
     void addWrappedQtHeadersIncludePath(QStringList &list);
 
     QStringList m_options;
-    UseSystemHeader m_useSystemHeader;
 
     QString m_clangVersion;
     QString m_clangResourceDirectory;
 
+    UseSystemHeader m_useSystemHeader;
     SkipBuiltIn m_skipBuiltInHeaderPathsAndDefines;
+    SkipLanguageDefines m_skipLanguageDefines;
 };
 
 } // namespace CppTools
diff --git a/src/plugins/cpptools/cppcodemodelinspectordumper.cpp b/src/plugins/cpptools/cppcodemodelinspectordumper.cpp
index 6a0c1fe1240..e359f71a05d 100644
--- a/src/plugins/cpptools/cppcodemodelinspectordumper.cpp
+++ b/src/plugins/cpptools/cppcodemodelinspectordumper.cpp
@@ -103,37 +103,39 @@ QString Utils::toString(ProjectExplorer::HeaderPathType type)
     return QString();
 }
 
-QString Utils::toString(ProjectPart::LanguageVersion languageVersion)
+QString Utils::toString(ProjectExplorer::LanguageVersion languageVersion)
 {
-#define CASE_LANGUAGEVERSION(x) case ProjectPart::x: return QLatin1String(#x)
+#define CASE_LANGUAGEVERSION(x) case ProjectExplorer::LanguageVersion::x: return QLatin1String(#x)
     switch (languageVersion) {
     CASE_LANGUAGEVERSION(C89);
     CASE_LANGUAGEVERSION(C99);
     CASE_LANGUAGEVERSION(C11);
+    CASE_LANGUAGEVERSION(C18);
     CASE_LANGUAGEVERSION(CXX98);
     CASE_LANGUAGEVERSION(CXX03);
     CASE_LANGUAGEVERSION(CXX11);
     CASE_LANGUAGEVERSION(CXX14);
     CASE_LANGUAGEVERSION(CXX17);
+    CASE_LANGUAGEVERSION(CXX2a);
     // no default to get a compiler warning if anything is added
     }
 #undef CASE_LANGUAGEVERSION
     return QString();
 }
 
-QString Utils::toString(ProjectPart::LanguageExtensions languageExtension)
+QString Utils::toString(ProjectExplorer::LanguageExtensions languageExtension)
 {
     QString result;
 
-#define CASE_LANGUAGE_EXTENSION(ext) if (languageExtension & ProjectPart::ext) \
+#define CASE_LANGUAGE_EXTENSION(ext) if (languageExtension & ProjectExplorer::LanguageExtension::ext) \
     result += QLatin1String(#ext ", ");
 
-    CASE_LANGUAGE_EXTENSION(NoExtensions);
-    CASE_LANGUAGE_EXTENSION(GnuExtensions);
-    CASE_LANGUAGE_EXTENSION(MicrosoftExtensions);
-    CASE_LANGUAGE_EXTENSION(BorlandExtensions);
-    CASE_LANGUAGE_EXTENSION(OpenMPExtensions);
-    CASE_LANGUAGE_EXTENSION(ObjectiveCExtensions);
+    CASE_LANGUAGE_EXTENSION(None);
+    CASE_LANGUAGE_EXTENSION(Gnu);
+    CASE_LANGUAGE_EXTENSION(Microsoft);
+    CASE_LANGUAGE_EXTENSION(Borland);
+    CASE_LANGUAGE_EXTENSION(OpenMP);
+    CASE_LANGUAGE_EXTENSION(ObjectiveC);
 #undef CASE_LANGUAGE_EXTENSION
     if (result.endsWith(QLatin1String(", ")))
         result.chop(2);
@@ -146,8 +148,7 @@ QString Utils::toString(ProjectPart::QtVersion qtVersion)
     switch (qtVersion) {
     CASE_QTVERSION(UnknownQt);
     CASE_QTVERSION(NoQt);
-    CASE_QTVERSION(Qt4_8_6AndOlder);
-    CASE_QTVERSION(Qt4Latest);
+    CASE_QTVERSION(Qt4);
     CASE_QTVERSION(Qt5);
     // no default to get a compiler warning if anything is added
     }
diff --git a/src/plugins/cpptools/cppcodemodelinspectordumper.h b/src/plugins/cpptools/cppcodemodelinspectordumper.h
index d460acf4965..b0f7a18a011 100644
--- a/src/plugins/cpptools/cppcodemodelinspectordumper.h
+++ b/src/plugins/cpptools/cppcodemodelinspectordumper.h
@@ -47,8 +47,8 @@ struct CPPTOOLS_EXPORT Utils
     static QString toString(CPlusPlus::Document::CheckMode checkMode);
     static QString toString(CPlusPlus::Document::DiagnosticMessage::Level level);
     static QString toString(ProjectExplorer::HeaderPathType type);
-    static QString toString(CppTools::ProjectPart::LanguageVersion languageVersion);
-    static QString toString(CppTools::ProjectPart::LanguageExtensions languageExtension);
+    static QString toString(ProjectExplorer::LanguageVersion languageVersion);
+    static QString toString(ProjectExplorer::LanguageExtensions languageExtension);
     static QString toString(CppTools::ProjectPart::QtVersion qtVersion);
     static QString toString(CppTools::ProjectPart::BuildTargetType buildTargetType);
     static QString toString(const QVector<CppTools::ProjectFile> &projectFiles);
diff --git a/src/plugins/cpptools/cppmodelmanager.cpp b/src/plugins/cpptools/cppmodelmanager.cpp
index 9303d663388..5db9dd601d1 100644
--- a/src/plugins/cpptools/cppmodelmanager.cpp
+++ b/src/plugins/cpptools/cppmodelmanager.cpp
@@ -1170,8 +1170,9 @@ ProjectPart::Ptr CppModelManager::fallbackProjectPart()
 
     // Do not activate ObjectiveCExtensions since this will lead to the
     // "objective-c++" language option for a project-less *.cpp file.
-    part->languageExtensions = ProjectPart::AllExtensions;
-    part->languageExtensions &= ~ProjectPart::ObjectiveCExtensions;
+    part->languageExtensions = ProjectExplorer::LanguageExtension::All;
+    part->languageExtensions &= ~ProjectExplorer::LanguageExtensions(
+        ProjectExplorer::LanguageExtension::ObjectiveC);
 
     part->qtVersion = ProjectPart::Qt5;
     part->updateLanguageFeatures();
diff --git a/src/plugins/cpptools/cppprojectinfogenerator.cpp b/src/plugins/cpptools/cppprojectinfogenerator.cpp
index fd1c9280902..0eb1af9c6e7 100644
--- a/src/plugins/cpptools/cppprojectinfogenerator.cpp
+++ b/src/plugins/cpptools/cppprojectinfogenerator.cpp
@@ -30,125 +30,11 @@
 #include <projectexplorer/headerpath.h>
 #include <projectexplorer/projectexplorerconstants.h>
 
+#include <utils/qtcassert.h>
+
 namespace CppTools {
 namespace Internal {
 
-namespace {
-
-class ToolChainEvaluator
-{
-public:
-    ToolChainEvaluator(ProjectPart &projectPart,
-                       const RawProjectPartFlags &flags,
-                       const ToolChainInfo &tcInfo)
-        : m_projectPart(projectPart)
-        , m_flags(flags)
-        , m_tcInfo(tcInfo)
-    {
-    }
-
-    void evaluate()
-    {
-        m_projectPart.toolchainType = m_tcInfo.type;
-        m_projectPart.isMsvc2015Toolchain = m_tcInfo.isMsvc2015ToolChain;
-        m_projectPart.toolChainWordWidth = mapWordWith(m_tcInfo.wordWidth);
-        m_projectPart.toolChainTargetTriple = m_tcInfo.targetTriple;
-        m_projectPart.extraCodeModelFlags = m_tcInfo.extraCodeModelFlags;
-
-        m_projectPart.warningFlags = m_flags.warningFlags;
-
-        // For compilation database pass the command line flags directly.
-        if (m_projectPart.toolchainType == ProjectExplorer::Constants::COMPILATION_DATABASE_TOOLCHAIN_TYPEID)
-            m_projectPart.extraCodeModelFlags = m_flags.commandLineFlags;
-
-        mapLanguageVersion();
-        mapLanguageExtensions();
-
-        addHeaderPaths();
-        addDefines();
-    }
-
-private:
-    static ProjectPart::ToolChainWordWidth mapWordWith(unsigned wordWidth)
-    {
-        return wordWidth == 64
-                ? ProjectPart::WordWidth64Bit
-                : ProjectPart::WordWidth32Bit;
-    }
-
-    void mapLanguageVersion()
-    {
-        using namespace ProjectExplorer;
-
-        const ToolChain::CompilerFlags &compilerFlags = m_flags.compilerFlags;
-        ProjectPart::LanguageVersion &languageVersion = m_projectPart.languageVersion;
-
-        if (compilerFlags & ToolChain::StandardC11)
-            languageVersion = ProjectPart::C11;
-        else if (compilerFlags & ToolChain::StandardC99)
-            languageVersion = ProjectPart::C99;
-        else if (compilerFlags & ToolChain::StandardCxx17)
-            languageVersion = ProjectPart::CXX17;
-        else if (compilerFlags & ToolChain::StandardCxx14)
-            languageVersion = ProjectPart::CXX14;
-        else if (compilerFlags & ToolChain::StandardCxx11)
-            languageVersion = ProjectPart::CXX11;
-        else if (compilerFlags & ToolChain::StandardCxx98)
-            languageVersion = ProjectPart::CXX98;
-    }
-
-    void mapLanguageExtensions()
-    {
-        using namespace ProjectExplorer;
-
-        const ToolChain::CompilerFlags &compilerFlags = m_flags.compilerFlags;
-        ProjectPart::LanguageExtensions &languageExtensions = m_projectPart.languageExtensions;
-
-        if (compilerFlags & ToolChain::BorlandExtensions)
-            languageExtensions |= ProjectPart::BorlandExtensions;
-        if (compilerFlags & ToolChain::GnuExtensions)
-            languageExtensions |= ProjectPart::GnuExtensions;
-        if (compilerFlags & ToolChain::MicrosoftExtensions)
-            languageExtensions |= ProjectPart::MicrosoftExtensions;
-        if (compilerFlags & ToolChain::OpenMP)
-            languageExtensions |= ProjectPart::OpenMPExtensions;
-        if (compilerFlags & ToolChain::ObjectiveC)
-            languageExtensions |= ProjectPart::ObjectiveCExtensions;
-    }
-
-    void addHeaderPaths()
-    {
-        if (!m_tcInfo.headerPathsRunner)
-            return; // No compiler set in kit.
-
-        const ProjectExplorer::HeaderPaths builtInHeaderPaths
-                = m_tcInfo.headerPathsRunner(m_flags.commandLineFlags,
-                                             m_tcInfo.sysRootPath);
-
-        ProjectExplorer::HeaderPaths &headerPaths = m_projectPart.headerPaths;
-        for (const ProjectExplorer::HeaderPath &header : builtInHeaderPaths) {
-            const ProjectExplorer::HeaderPath headerPath{header.path, header.type};
-            if (!headerPaths.contains(headerPath))
-                headerPaths.push_back(headerPath);
-        }
-    }
-
-    void addDefines()
-    {
-        if (!m_tcInfo.predefinedMacrosRunner)
-            return; // No compiler set in kit.
-
-        m_projectPart.toolChainMacros = m_tcInfo.predefinedMacrosRunner(m_flags.commandLineFlags);
-    }
-
-private:
-    ProjectPart &m_projectPart;
-    const RawProjectPartFlags &m_flags;
-    const ToolChainInfo &m_tcInfo;
-};
-
-} // anonymous namespace
-
 ProjectInfoGenerator::ProjectInfoGenerator(const QFutureInterface<void> &futureInterface,
                                            const ProjectUpdateInfo &projectUpdateInfo)
     : m_futureInterface(futureInterface)
@@ -196,6 +82,8 @@ static ProjectPart::Ptr projectPartFromRawProjectPart(const RawProjectPart &rawP
 
 QVector<ProjectPart::Ptr> ProjectInfoGenerator::createProjectParts(const RawProjectPart &rawProjectPart)
 {
+    using ProjectExplorer::LanguageExtension;
+
     QVector<ProjectPart::Ptr> result;
     ProjectFileCategorizer cat(rawProjectPart.displayName,
                                rawProjectPart.files,
@@ -205,16 +93,13 @@ QVector<ProjectPart::Ptr> ProjectInfoGenerator::createProjectParts(const RawProj
         const ProjectPart::Ptr part = projectPartFromRawProjectPart(rawProjectPart,
                                                                     m_projectUpdateInfo.project);
 
-        ProjectPart::LanguageVersion defaultVersion = ProjectPart::LatestCxxVersion;
-        if (rawProjectPart.qtVersion == ProjectPart::Qt4_8_6AndOlder)
-            defaultVersion = ProjectPart::CXX11;
         if (cat.hasCxxSources()) {
             result << createProjectPart(rawProjectPart,
                                         part,
                                         cat.cxxSources(),
                                         cat.partName("C++"),
-                                        defaultVersion,
-                                        ProjectPart::NoExtensions);
+                                        Language::Cxx,
+                                        LanguageExtension::None);
         }
 
         if (cat.hasObjcxxSources()) {
@@ -222,8 +107,8 @@ QVector<ProjectPart::Ptr> ProjectInfoGenerator::createProjectParts(const RawProj
                                         part,
                                         cat.objcxxSources(),
                                         cat.partName("Obj-C++"),
-                                        defaultVersion,
-                                        ProjectPart::ObjectiveCExtensions);
+                                        Language::Cxx,
+                                        LanguageExtension::ObjectiveC);
         }
 
         if (cat.hasCSources()) {
@@ -231,8 +116,8 @@ QVector<ProjectPart::Ptr> ProjectInfoGenerator::createProjectParts(const RawProj
                                         part,
                                         cat.cSources(),
                                         cat.partName("C"),
-                                        ProjectPart::LatestCVersion,
-                                        ProjectPart::NoExtensions);
+                                        Language::C,
+                                        LanguageExtension::None);
         }
 
         if (cat.hasObjcSources()) {
@@ -240,28 +125,24 @@ QVector<ProjectPart::Ptr> ProjectInfoGenerator::createProjectParts(const RawProj
                                         part,
                                         cat.objcSources(),
                                         cat.partName("Obj-C"),
-                                        ProjectPart::LatestCVersion,
-                                        ProjectPart::ObjectiveCExtensions);
+                                        Language::C,
+                                        LanguageExtension::ObjectiveC);
         }
     }
     return result;
 }
 
-ProjectPart::Ptr ProjectInfoGenerator::createProjectPart(const RawProjectPart &rawProjectPart,
-                                                         const ProjectPart::Ptr &templateProjectPart,
-                                                         const ProjectFiles &projectFiles,
-                                                         const QString &partName,
-                                                         ProjectPart::LanguageVersion languageVersion,
-                                                         ProjectPart::LanguageExtensions languageExtensions)
+ProjectPart::Ptr ProjectInfoGenerator::createProjectPart(
+    const RawProjectPart &rawProjectPart,
+    const ProjectPart::Ptr &templateProjectPart,
+    const ProjectFiles &projectFiles,
+    const QString &partName,
+    Language language,
+    ProjectExplorer::LanguageExtensions languageExtensions)
 {
-    ProjectPart::Ptr part(templateProjectPart->copy());
-    part->displayName = partName;
-    part->files = projectFiles;
-    part->languageVersion = languageVersion;
-
     RawProjectPartFlags flags;
     ToolChainInfo tcInfo;
-    if (languageVersion <= ProjectPart::LatestCVersion) {
+    if (language == Language::C) {
         flags = rawProjectPart.flagsForC;
         tcInfo = m_projectUpdateInfo.cToolChainInfo;
     }
@@ -271,8 +152,46 @@ ProjectPart::Ptr ProjectInfoGenerator::createProjectPart(const RawProjectPart &r
         tcInfo = m_projectUpdateInfo.cxxToolChainInfo;
     }
     // TODO: If no toolchain is set, show a warning
-    ToolChainEvaluator evaluator(*part.data(), flags, tcInfo);
-    evaluator.evaluate();
+
+    ProjectPart::Ptr part(templateProjectPart->copy());
+    part->displayName = partName;
+    part->files = projectFiles;
+    part->toolchainType = tcInfo.type;
+    part->isMsvc2015Toolchain = tcInfo.isMsvc2015ToolChain;
+    part->toolChainWordWidth = tcInfo.wordWidth == 64 ? ProjectPart::WordWidth64Bit
+                                                      : ProjectPart::WordWidth32Bit;
+    part->toolChainTargetTriple = tcInfo.targetTriple;
+    part->extraCodeModelFlags = tcInfo.extraCodeModelFlags;
+    part->warningFlags = flags.warningFlags;
+    part->languageExtensions = flags.languageExtensions;
+
+    if (part->toolchainType == ProjectExplorer::Constants::COMPILATION_DATABASE_TOOLCHAIN_TYPEID)
+        part->extraCodeModelFlags = flags.commandLineFlags;
+
+    // Toolchain macros and language version
+    if (tcInfo.macroInspectionRunner) {
+        auto macroInspectionReport = tcInfo.macroInspectionRunner(flags.commandLineFlags);
+        part->toolChainMacros = macroInspectionReport.macros;
+        part->languageVersion = macroInspectionReport.languageVersion;
+    // No compiler set in kit.
+    } else if (language == Language::C) {
+        part->languageVersion = ProjectExplorer::LanguageVersion::LatestC;
+    } else {
+        part->languageVersion = ProjectExplorer::LanguageVersion::LatestCxx;
+    }
+
+    // Header paths
+    if (tcInfo.headerPathsRunner) {
+        const ProjectExplorer::HeaderPaths builtInHeaderPaths
+            = tcInfo.headerPathsRunner(flags.commandLineFlags, tcInfo.sysRootPath);
+
+        ProjectExplorer::HeaderPaths &headerPaths = part->headerPaths;
+        for (const ProjectExplorer::HeaderPath &header : builtInHeaderPaths) {
+            const ProjectExplorer::HeaderPath headerPath{header.path, header.type};
+            if (!headerPaths.contains(headerPath))
+                headerPaths.push_back(headerPath);
+        }
+    }
 
     part->languageExtensions |= languageExtensions;
     part->updateLanguageFeatures();
diff --git a/src/plugins/cpptools/cppprojectinfogenerator.h b/src/plugins/cpptools/cppprojectinfogenerator.h
index 6f81eaf85f5..6f97faf9cbf 100644
--- a/src/plugins/cpptools/cppprojectinfogenerator.h
+++ b/src/plugins/cpptools/cppprojectinfogenerator.h
@@ -25,6 +25,7 @@
 
 #pragma once
 
+#include "cpptools_utils.h"
 #include "projectinfo.h"
 
 #include <QFutureInterface>
@@ -46,8 +47,8 @@ private:
                                        const ProjectPart::Ptr &templateProjectPart,
                                        const ProjectFiles &projectFiles,
                                        const QString &partName,
-                                       ProjectPart::LanguageVersion languageVersion,
-                                       ProjectPart::LanguageExtensions languageExtensions);
+                                       Language language,
+                                       ProjectExplorer::LanguageExtensions languageExtensions);
 
 private:
     const QFutureInterface<void> m_futureInterface;
diff --git a/src/plugins/cpptools/cppprojectpartchooser.cpp b/src/plugins/cpptools/cppprojectpartchooser.cpp
index bbf9ca35594..a7bb56beb04 100644
--- a/src/plugins/cpptools/cppprojectpartchooser.cpp
+++ b/src/plugins/cpptools/cppprojectpartchooser.cpp
@@ -116,7 +116,8 @@ private:
 
     bool isPreferredLanguage(const ProjectPart &projectPart) const
     {
-        const bool isCProjectPart = projectPart.languageVersion <= ProjectPart::LatestCVersion;
+        const bool isCProjectPart = projectPart.languageVersion
+                                    <= ProjectExplorer::LanguageVersion::LatestC;
         return (m_languagePreference == Language::C && isCProjectPart)
             || (m_languagePreference == Language::Cxx && !isCProjectPart);
     }
diff --git a/src/plugins/cpptools/cpprawprojectpart.cpp b/src/plugins/cpptools/cpprawprojectpart.cpp
index 6f60d9cf46f..9675be52919 100644
--- a/src/plugins/cpptools/cpprawprojectpart.cpp
+++ b/src/plugins/cpptools/cpprawprojectpart.cpp
@@ -39,7 +39,7 @@ RawProjectPartFlags::RawProjectPartFlags(const ProjectExplorer::ToolChain *toolC
     if (toolChain) {
         this->commandLineFlags = commandLineFlags;
         warningFlags = toolChain->warningFlags(commandLineFlags);
-        compilerFlags = toolChain->compilerFlags(commandLineFlags);
+        languageExtensions = toolChain->languageExtensions(commandLineFlags);
     }
 }
 
diff --git a/src/plugins/cpptools/cpprawprojectpart.h b/src/plugins/cpptools/cpprawprojectpart.h
index 4aa17a3a47d..e238fa1d818 100644
--- a/src/plugins/cpptools/cpprawprojectpart.h
+++ b/src/plugins/cpptools/cpprawprojectpart.h
@@ -28,6 +28,7 @@
 #include "cpptools_global.h"
 #include "projectpart.h"
 
+#include <projectexplorer/language.h>
 #include <projectexplorer/toolchain.h>
 
 #include <functional>
@@ -45,8 +46,7 @@ public:
     QStringList commandLineFlags;
     // The following are deduced from commandLineFlags.
     ProjectExplorer::WarningFlags warningFlags = ProjectExplorer::WarningFlags::Default;
-    ProjectExplorer::ToolChain::CompilerFlags compilerFlags
-        = ProjectExplorer::ToolChain::CompilerFlag::NoFlags;
+    ProjectExplorer::LanguageExtensions languageExtensions = ProjectExplorer::LanguageExtension::None;
 };
 
 class CPPTOOLS_EXPORT RawProjectPart
diff --git a/src/plugins/cpptools/projectinfo.cpp b/src/plugins/cpptools/projectinfo.cpp
index a51caebe111..c39449fef7a 100644
--- a/src/plugins/cpptools/projectinfo.cpp
+++ b/src/plugins/cpptools/projectinfo.cpp
@@ -48,7 +48,7 @@ ToolChainInfo::ToolChainInfo(const ProjectExplorer::ToolChain *toolChain,
         // they can be run from a worker thread.
         sysRootPath = ProjectExplorer::SysRootKitInformation::sysRoot(kit).toString();
         headerPathsRunner = toolChain->createBuiltInHeaderPathsRunner();
-        predefinedMacrosRunner = toolChain->createPredefinedMacrosRunner();
+        macroInspectionRunner = toolChain->createMacroInspectionRunner();
     }
 }
 
diff --git a/src/plugins/cpptools/projectinfo.h b/src/plugins/cpptools/projectinfo.h
index 38bf509cba2..a69ffd8fdfe 100644
--- a/src/plugins/cpptools/projectinfo.h
+++ b/src/plugins/cpptools/projectinfo.h
@@ -58,7 +58,7 @@ public:
 
     QString sysRootPath; // For headerPathsRunner.
     ProjectExplorer::ToolChain::BuiltInHeaderPathsRunner headerPathsRunner;
-    ProjectExplorer::ToolChain::PredefinedMacrosRunner predefinedMacrosRunner;
+    ProjectExplorer::ToolChain::MacroInspectionRunner macroInspectionRunner;
 };
 
 class CPPTOOLS_EXPORT ProjectUpdateInfo
diff --git a/src/plugins/cpptools/projectpart.cpp b/src/plugins/cpptools/projectpart.cpp
index 4dc871e87ea..bcfe4b3e52d 100644
--- a/src/plugins/cpptools/projectpart.cpp
+++ b/src/plugins/cpptools/projectpart.cpp
@@ -35,12 +35,13 @@ namespace CppTools {
 
 void ProjectPart::updateLanguageFeatures()
 {
-    const bool hasCxx = languageVersion >= CXX98;
+    const bool hasCxx = languageVersion >= ProjectExplorer::LanguageVersion::CXX98;
     const bool hasQt = hasCxx && qtVersion != NoQt;
-    languageFeatures.cxx11Enabled = languageVersion >= CXX11;
+    languageFeatures.cxx11Enabled = languageVersion >= ProjectExplorer::LanguageVersion::CXX11;
     languageFeatures.cxxEnabled = hasCxx;
-    languageFeatures.c99Enabled = languageVersion >= C99;
-    languageFeatures.objCEnabled = languageExtensions.testFlag(ObjectiveCExtensions);
+    languageFeatures.c99Enabled = languageVersion >= ProjectExplorer::LanguageVersion::C99;
+    languageFeatures.objCEnabled = languageExtensions.testFlag(
+        ProjectExplorer::LanguageExtension::ObjectiveC);
     languageFeatures.qtEnabled = hasQt;
     languageFeatures.qtMocRunEnabled = hasQt;
     if (!hasQt) {
diff --git a/src/plugins/cpptools/projectpart.h b/src/plugins/cpptools/projectpart.h
index ce017abc79d..77a08128bfb 100644
--- a/src/plugins/cpptools/projectpart.h
+++ b/src/plugins/cpptools/projectpart.h
@@ -30,6 +30,7 @@
 #include "cppprojectfile.h"
 
 #include <projectexplorer/headerpath.h>
+#include <projectexplorer/language.h>
 #include <projectexplorer/projectexplorer_global.h>
 #include <projectexplorer/projectmacro.h>
 
@@ -49,40 +50,10 @@ namespace CppTools {
 class CPPTOOLS_EXPORT ProjectPart
 {
 public:
-    enum LanguageVersion {
-        C89,
-        C99,
-        C11,
-        LatestCVersion = C11,
-        CXX98,
-        CXX03,
-        CXX11,
-        CXX14,
-        CXX17,
-        LatestCxxVersion = CXX17,
-    };
-
-    enum LanguageExtension {
-        NoExtensions         = 0,
-        GnuExtensions        = 1 << 0,
-        MicrosoftExtensions  = 1 << 1,
-        BorlandExtensions    = 1 << 2,
-        OpenMPExtensions     = 1 << 3,
-        ObjectiveCExtensions = 1 << 4,
-
-        AllExtensions = GnuExtensions
-                      | MicrosoftExtensions
-                      | BorlandExtensions
-                      | OpenMPExtensions
-                      | ObjectiveCExtensions
-    };
-    Q_DECLARE_FLAGS(LanguageExtensions, LanguageExtension)
-
     enum QtVersion {
         UnknownQt = -1,
         NoQt,
-        Qt4_8_6AndOlder,
-        Qt4Latest,
+        Qt4,
         Qt5
     };
 
@@ -127,8 +98,8 @@ public:
 
     ProjectExplorer::Macros projectMacros;
 
-    LanguageVersion languageVersion = LatestCxxVersion;
-    LanguageExtensions languageExtensions = NoExtensions;
+    ProjectExplorer::LanguageVersion languageVersion = ProjectExplorer::LanguageVersion::LatestCxx;
+    ProjectExplorer::LanguageExtensions languageExtensions = ProjectExplorer::LanguageExtension::None;
     ProjectExplorer::WarningFlags warningFlags = ProjectExplorer::WarningFlags::Default;
     QtVersion qtVersion = UnknownQt;
     CPlusPlus::LanguageFeatures languageFeatures;
diff --git a/src/plugins/cpptools/symbolsfindfilter.cpp b/src/plugins/cpptools/symbolsfindfilter.cpp
index 0afd65db18c..58e0ba11d3e 100644
--- a/src/plugins/cpptools/symbolsfindfilter.cpp
+++ b/src/plugins/cpptools/symbolsfindfilter.cpp
@@ -191,18 +191,20 @@ QWidget *SymbolsFindFilter::createConfigWidget()
 void SymbolsFindFilter::writeSettings(QSettings *settings)
 {
     settings->beginGroup(QLatin1String(SETTINGS_GROUP));
-    settings->setValue(QLatin1String(SETTINGS_SYMBOLTYPES), (int)m_symbolsToSearch);
-    settings->setValue(QLatin1String(SETTINGS_SEARCHSCOPE), (int)m_scope);
+    settings->setValue(QLatin1String(SETTINGS_SYMBOLTYPES), int(m_symbolsToSearch));
+    settings->setValue(QLatin1String(SETTINGS_SEARCHSCOPE), int(m_scope));
     settings->endGroup();
 }
 
 void SymbolsFindFilter::readSettings(QSettings *settings)
 {
     settings->beginGroup(QLatin1String(SETTINGS_GROUP));
-    m_symbolsToSearch = (SearchSymbols::SymbolTypes)settings->value(QLatin1String(SETTINGS_SYMBOLTYPES),
-                                        (int)SearchSymbols::AllTypes).toInt();
-    m_scope = (SearchScope)settings->value(QLatin1String(SETTINGS_SEARCHSCOPE),
-                                           (int)SymbolSearcher::SearchProjectsOnly).toInt();
+    m_symbolsToSearch = static_cast<SearchSymbols::SymbolTypes>(
+                settings->value(QLatin1String(SETTINGS_SYMBOLTYPES),
+                                int(SearchSymbols::AllTypes)).toInt());
+    m_scope = static_cast<SearchScope>(
+                settings->value(QLatin1String(SETTINGS_SEARCHSCOPE),
+                                int(SymbolSearcher::SearchProjectsOnly)).toInt());
     settings->endGroup();
     emit symbolsToSearchChanged();
 }
diff --git a/src/plugins/debugger/cdb/cdbengine.cpp b/src/plugins/debugger/cdb/cdbengine.cpp
index 255712aa67e..a047ac1d7c5 100644
--- a/src/plugins/debugger/cdb/cdbengine.cpp
+++ b/src/plugins/debugger/cdb/cdbengine.cpp
@@ -201,8 +201,6 @@ CdbEngine::CdbEngine() :
     wh->addTypeFormats("QImage", imageFormats);
     wh->addTypeFormats("QImage *", imageFormats);
 
-    connect(action(OperateByInstruction), &QAction::triggered,
-            this, &CdbEngine::operateByInstructionTriggered);
     connect(action(CreateFullBacktrace), &QAction::triggered,
             this, &CdbEngine::createFullBacktrace);
     connect(&m_process, static_cast<void(QProcess::*)(int)>(&QProcess::finished),
@@ -270,6 +268,7 @@ CdbEngine::~CdbEngine() = default;
 
 void CdbEngine::operateByInstructionTriggered(bool operateByInstruction)
 {
+    DebuggerEngine::operateByInstructionTriggered(operateByInstruction);
     if (m_operateByInstruction == operateByInstruction)
         return;
     m_operateByInstruction = operateByInstruction;
@@ -522,7 +521,7 @@ void CdbEngine::handleInitialSessionIdle()
     const DebuggerRunParameters &rp = runParameters();
     if (!rp.commandsAfterConnect.isEmpty())
         runCommand({rp.commandsAfterConnect, NoFlags});
-    operateByInstructionTriggered(action(OperateByInstruction)->isChecked());
+    operateByInstructionTriggered(operatesByInstruction());
     // QmlCppEngine expects the QML engine to be connected before any breakpoints are hit
     // (attemptBreakpointSynchronization() will be directly called then)
     if (rp.breakOnMain) {
diff --git a/src/plugins/debugger/cdb/cdbengine.h b/src/plugins/debugger/cdb/cdbengine.h
index e5b617eb437..c367925fd3a 100644
--- a/src/plugins/debugger/cdb/cdbengine.h
+++ b/src/plugins/debugger/cdb/cdbengine.h
@@ -113,7 +113,7 @@ private:
     void processError();
     void processFinished();
     void runCommand(const DebuggerCommand &cmd) override;
-    void operateByInstructionTriggered(bool);
+    void operateByInstructionTriggered(bool) override;
 
     void createFullBacktrace();
 
diff --git a/src/plugins/debugger/debuggeractions.cpp b/src/plugins/debugger/debuggeractions.cpp
index cfb35146834..6d44afdadcd 100644
--- a/src/plugins/debugger/debuggeractions.cpp
+++ b/src/plugins/debugger/debuggeractions.cpp
@@ -165,18 +165,6 @@ DebuggerSettings::DebuggerSettings()
     item->setDefaultValue(false);
     insertItem(LogTimeStamps, item);
 
-    item = new SavedAction(this);
-    item->setText(tr("Operate by Instruction"));
-    item->setCheckable(true);
-    item->setDefaultValue(false);
-    item->setIcon(Debugger::Icons::SINGLE_INSTRUCTION_MODE.icon());
-    item->setToolTip(tr("<p>This switches the debugger to instruction-wise "
-        "operation mode. In this mode, stepping operates on single "
-        "instructions and the source location view also shows the "
-        "disassembled instructions."));
-    item->setIconVisibleInMenu(false);
-    insertItem(OperateByInstruction, item);
-
     item = new SavedAction(this);
     item->setText(tr("Dereference Pointers Automatically"));
     item->setCheckable(true);
diff --git a/src/plugins/debugger/debuggeractions.h b/src/plugins/debugger/debuggeractions.h
index 39d3571d45e..6a91a0fc43e 100644
--- a/src/plugins/debugger/debuggeractions.h
+++ b/src/plugins/debugger/debuggeractions.h
@@ -82,7 +82,6 @@ enum DebuggerActionCode
     AutoQuit,
     LockView,
     LogTimeStamps,
-    OperateByInstruction,
     CloseSourceBuffersOnExit,
     CloseMemoryBuffersOnExit,
     SwitchModeOnExit,
diff --git a/src/plugins/debugger/debuggerengine.cpp b/src/plugins/debugger/debuggerengine.cpp
index 67a01d026c1..cbc1be8b779 100644
--- a/src/plugins/debugger/debuggerengine.cpp
+++ b/src/plugins/debugger/debuggerengine.cpp
@@ -393,23 +393,6 @@ public:
         m_toolTipManager.resetLocation();
     }
 
-    void handleOperateByInstructionTriggered(bool on)
-    {
-        // Go to source only if we have the file.
-        //    if (DebuggerEngine *cppEngine = m_engine->cppEngine()) {
-        if (m_stackHandler.currentIndex() >= 0) {
-            const StackFrame frame = m_stackHandler.currentFrame();
-            if (on || frame.isUsable())
-                m_engine->gotoLocation(Location(frame, true));
-        }
-        //    }
-    }
-
-    bool operatesByInstruction() const
-    {
-        return m_operateByInstructionAction.isChecked();
-    }
-
 public:
     void setInitialActionStates();
     void setBusyCursor(bool on);
@@ -542,9 +525,15 @@ void DebuggerEnginePrivate::setupViews()
     m_operateByInstructionAction.setVisible(m_engine->hasCapability(DisassemblerCapability));
     m_operateByInstructionAction.setIcon(Debugger::Icons::SINGLE_INSTRUCTION_MODE.icon());
     m_operateByInstructionAction.setCheckable(true);
-    m_operateByInstructionAction.setChecked(boolSetting(OperateByInstruction));
+    m_operateByInstructionAction.setChecked(false);
+    m_operateByInstructionAction.setToolTip("<p>" + tr("This switches the debugger to instruction-wise "
+        "operation mode. In this mode, stepping operates on single "
+        "instructions and the source location view also shows the "
+        "disassembled instructions."));
+    m_operateByInstructionAction.setIconVisibleInMenu(false);
+
     connect(&m_operateByInstructionAction, &QAction::triggered,
-            this, &DebuggerEnginePrivate::handleOperateByInstructionTriggered);
+            m_engine, &DebuggerEngine::operateByInstructionTriggered);
 
     QTC_ASSERT(m_state == DebuggerNotReady || m_state == DebuggerFinished, qDebug() << m_state);
     m_progress.setProgressValue(200);
@@ -977,7 +966,7 @@ void DebuggerEngine::gotoLocation(const Location &loc)
      d->resetLocation();
 
     if (loc.canBeDisassembled()
-            && ((hasCapability(OperateByInstructionCapability) && d->operatesByInstruction())
+            && ((hasCapability(OperateByInstructionCapability) && operatesByInstruction())
                 || !loc.hasDebugInfo()) )
     {
         d->m_disassemblerAgent.setLocation(loc);
@@ -1803,6 +1792,24 @@ bool DebuggerEngine::debuggerActionsEnabled() const
     return debuggerActionsEnabledHelper(d->m_state);
 }
 
+bool DebuggerEngine::operatesByInstruction() const
+{
+    return d->m_operateByInstructionAction.isChecked();
+}
+
+void DebuggerEngine::operateByInstructionTriggered(bool on)
+{
+    // Go to source only if we have the file.
+    //    if (DebuggerEngine *cppEngine = m_engine->cppEngine()) {
+    d->m_stackHandler.resetModel();
+    if (d->m_stackHandler.currentIndex() >= 0) {
+        const StackFrame frame = d->m_stackHandler.currentFrame();
+        if (on || frame.isUsable())
+            gotoLocation(Location(frame, true));
+    }
+    //    }
+}
+
 bool DebuggerEngine::companionPreventsActions() const
 {
     return false;
@@ -2291,7 +2298,7 @@ void DebuggerEngine::handleExecStep()
         ProjectExplorerPlugin::runStartupProject(ProjectExplorer::Constants::DEBUG_RUN_MODE);
     } else {
         resetLocation();
-        if (d->operatesByInstruction())
+        if (operatesByInstruction())
             executeStepI();
         else
             executeStep();
@@ -2305,7 +2312,7 @@ void DebuggerEngine::handleExecNext()
         ProjectExplorerPlugin::runStartupProject(ProjectExplorer::Constants::DEBUG_RUN_MODE);
     } else {
         resetLocation();
-        if (d->operatesByInstruction())
+        if (operatesByInstruction())
             executeNextI();
         else
             executeNext();
diff --git a/src/plugins/debugger/debuggerengine.h b/src/plugins/debugger/debuggerengine.h
index b9a31caf512..05c30078d4f 100644
--- a/src/plugins/debugger/debuggerengine.h
+++ b/src/plugins/debugger/debuggerengine.h
@@ -338,6 +338,9 @@ public:
     bool debuggerActionsEnabled() const;
     virtual bool companionPreventsActions() const;
 
+    bool operatesByInstruction() const;
+    virtual void operateByInstructionTriggered(bool on); // FIXME: Remove.
+
     DebuggerState state() const;
     bool isDying() const;
 
diff --git a/src/plugins/debugger/debuggerplugin.cpp b/src/plugins/debugger/debuggerplugin.cpp
index 81c657345bc..eb194281d9e 100644
--- a/src/plugins/debugger/debuggerplugin.cpp
+++ b/src/plugins/debugger/debuggerplugin.cpp
@@ -1233,7 +1233,7 @@ bool DebuggerPluginPrivate::initialize(const QStringList &arguments,
     m_nextAction.setIcon(Icons::STEP_OVER.icon());
     connect(&m_nextAction, &QAction::triggered, this, [] {
         if (DebuggerEngine *engine = EngineManager::currentEngine()) {
-            engine->executeNext();
+            engine->handleExecNext();
         } else {
             DebuggerRunTool::setBreakOnMainNextTime();
             ProjectExplorerPlugin::runStartupProject(ProjectExplorer::Constants::DEBUG_RUN_MODE, false);
@@ -1248,7 +1248,7 @@ bool DebuggerPluginPrivate::initialize(const QStringList &arguments,
     m_stepAction.setIcon(Icons::STEP_OVER.icon());
     connect(&m_stepAction, &QAction::triggered, this, [] {
         if (DebuggerEngine *engine = EngineManager::currentEngine()) {
-            engine->executeStep();
+            engine->handleExecStep();
         } else {
             DebuggerRunTool::setBreakOnMainNextTime();
             ProjectExplorerPlugin::runStartupProject(ProjectExplorer::Constants::DEBUG_RUN_MODE, false);
@@ -1298,10 +1298,10 @@ bool DebuggerPluginPrivate::initialize(const QStringList &arguments,
     ActionManager::registerAction(&m_frameUpAction,
         "Debugger.FrameUp", cppDebuggercontext);
 
-    cmd = ActionManager::registerAction(action(OperateByInstruction),
-        Constants::OPERATE_BY_INSTRUCTION, cppDebuggercontext);
-    cmd->setAttribute(Command::CA_Hide);
-    debugMenu->addAction(cmd);
+//    cmd = ActionManager::registerAction(action(OperateByInstruction),
+//        Constants::OPERATE_BY_INSTRUCTION, cppDebuggercontext);
+//    cmd->setAttribute(Command::CA_Hide);
+//    debugMenu->addAction(cmd);
 
     cmd = ActionManager::registerAction(&m_breakAction, "Debugger.ToggleBreak");
     cmd->setDefaultKeySequence(QKeySequence(useMacShortcuts ? tr("F8") : tr("F9")));
@@ -2056,7 +2056,6 @@ void DebuggerPluginPrivate::setInitialState()
     m_watchAction.setEnabled(false);
     m_breakAction.setEnabled(false);
     //m_snapshotAction.setEnabled(false);
-    action(OperateByInstruction)->setChecked(false);
 
     m_exitAction.setEnabled(false);
     m_abortAction.setEnabled(false);
diff --git a/src/plugins/debugger/debuggersourcepathmappingwidget.cpp b/src/plugins/debugger/debuggersourcepathmappingwidget.cpp
index 67915d8cfad..4d53e55f2d2 100644
--- a/src/plugins/debugger/debuggersourcepathmappingwidget.cpp
+++ b/src/plugins/debugger/debuggersourcepathmappingwidget.cpp
@@ -134,7 +134,7 @@ SourcePathMap SourcePathMappingModel::sourcePathMap() const
 bool SourcePathMappingModel::isNewPlaceHolder(const Mapping &m) const
 {
     const QLatin1Char lessThan('<');
-    const QLatin1Char greaterThan('<');
+    const QLatin1Char greaterThan('>');
     return m.first.isEmpty() || m.first.startsWith(lessThan)
            || m.first.endsWith(greaterThan)
            || m.first == m_newSourcePlaceHolder
diff --git a/src/plugins/debugger/gdb/gdbengine.cpp b/src/plugins/debugger/gdb/gdbengine.cpp
index 940909ab41a..d367b548c2a 100644
--- a/src/plugins/debugger/gdb/gdbengine.cpp
+++ b/src/plugins/debugger/gdb/gdbengine.cpp
@@ -1233,7 +1233,7 @@ void GdbEngine::handleStopResponse(const GdbMi &data)
 
     //qDebug() << "BP " << rid << data.toString();
     // Quickly set the location marker.
-    if (lineNumber && !boolSetting(OperateByInstruction)
+    if (lineNumber && !operatesByInstruction()
             && QFileInfo::exists(fullName)
             && function != "qt_v4TriggeredBreakpointHook"
             && function != "qt_qmlDebugMessageAvailable"
diff --git a/src/plugins/debugger/lldb/lldbengine.cpp b/src/plugins/debugger/lldb/lldbengine.cpp
index 17338305100..b8d414ad76c 100644
--- a/src/plugins/debugger/lldb/lldbengine.cpp
+++ b/src/plugins/debugger/lldb/lldbengine.cpp
@@ -891,7 +891,7 @@ void LldbEngine::handleLocationNotification(const GdbMi &reportedLocation)
     QString function = reportedLocation["function"].data();
     int lineNumber = reportedLocation["line"].toInt();
     Location loc = Location(fileName, lineNumber);
-    if (boolSetting(OperateByInstruction) || !QFileInfo::exists(fileName) || lineNumber <= 0) {
+    if (operatesByInstruction() || !QFileInfo::exists(fileName) || lineNumber <= 0) {
         loc = Location(address);
         loc.setNeedsMarker(true);
         loc.setUseAssembler(true);
diff --git a/src/plugins/debugger/stackhandler.cpp b/src/plugins/debugger/stackhandler.cpp
index c4bb6630b0b..e96f457ae6f 100644
--- a/src/plugins/debugger/stackhandler.cpp
+++ b/src/plugins/debugger/stackhandler.cpp
@@ -69,8 +69,6 @@ StackHandler::StackHandler(DebuggerEngine *engine)
 {
     setObjectName("StackModel");
 
-    connect(action(OperateByInstruction), &QAction::triggered,
-        this, &StackHandler::resetModel);
     connect(action(ExpandStack), &QAction::triggered,
         this, &StackHandler::reloadFullStack);
     connect(action(MaximalStackDepth), &QAction::triggered,
@@ -159,7 +157,7 @@ Qt::ItemFlags StackHandler::flags(const QModelIndex &index) const
     if (index.row() == m_stackFrames.size())
         return QAbstractTableModel::flags(index);
     const StackFrame &frame = m_stackFrames.at(index.row());
-    const bool isValid = frame.isUsable() || boolSetting(OperateByInstruction);
+    const bool isValid = frame.isUsable() || m_engine->operatesByInstruction();
     return isValid && m_contentsValid
             ? QAbstractTableModel::flags(index) : Qt::ItemFlags();
 }
@@ -258,7 +256,7 @@ void StackHandler::setFramesAndCurrentIndex(const GdbMi &frames, bool isFull)
     // a few exceptions:
 
     // Always jump to frame #0 when stepping by instruction.
-    if (boolSetting(OperateByInstruction))
+    if (m_engine->operatesByInstruction())
         targetFrame = 0;
 
     // If there is no frame with source, jump to frame #0.
@@ -284,7 +282,7 @@ void StackHandler::prependFrames(const StackFrames &frames)
 
 int StackHandler::firstUsableIndex() const
 {
-    if (!boolSetting(OperateByInstruction)) {
+    if (!m_engine->operatesByInstruction()) {
         for (int i = 0, n = m_stackFrames.size(); i != n; ++i)
             if (m_stackFrames.at(i).isUsable())
                 return i;
diff --git a/src/plugins/debugger/stackhandler.h b/src/plugins/debugger/stackhandler.h
index 0f06b77c755..02268e400af 100644
--- a/src/plugins/debugger/stackhandler.h
+++ b/src/plugins/debugger/stackhandler.h
@@ -73,6 +73,7 @@ public:
     bool isContentsValid() const { return m_contentsValid; }
     void scheduleResetLocation();
     void resetLocation();
+    void resetModel() { beginResetModel(); endResetModel(); }
 
 signals:
     void stackChanged();
@@ -87,7 +88,6 @@ private:
     bool setData(const QModelIndex &idx, const QVariant &data, int role) override;
 
     bool contextMenuEvent(const Utils::ItemViewEvent &event);
-    void resetModel() { beginResetModel(); endResetModel(); }
     void reloadFullStack();
     void copyContentsToClipboard();
     void saveTaskFile();
diff --git a/src/plugins/genericprojectmanager/genericproject.cpp b/src/plugins/genericprojectmanager/genericproject.cpp
index f1a47947eb3..b99d037e65f 100644
--- a/src/plugins/genericprojectmanager/genericproject.cpp
+++ b/src/plugins/genericprojectmanager/genericproject.cpp
@@ -239,7 +239,10 @@ bool GenericProject::saveRawList(const QStringList &rawList, const QString &file
 static void insertSorted(QStringList *list, const QString &value)
 {
     int pos = Utils::indexOf(*list, [value](const QString &s) { return s > value; });
-    list->insert(pos, value);
+    if (pos == -1)
+        list->append(value);
+    else
+        list->insert(pos, value);
 }
 
 bool GenericProject::addFiles(const QStringList &filePaths)
@@ -433,10 +436,8 @@ void GenericProject::refreshCppCodeModel()
     CppTools::ProjectPart::QtVersion activeQtVersion = CppTools::ProjectPart::NoQt;
     if (QtSupport::BaseQtVersion *qtVersion =
             QtSupport::QtKitInformation::qtVersion(activeTarget()->kit())) {
-        if (qtVersion->qtVersion() <= QtSupport::QtVersionNumber(4,8,6))
-            activeQtVersion = CppTools::ProjectPart::Qt4_8_6AndOlder;
-        else if (qtVersion->qtVersion() < QtSupport::QtVersionNumber(5,0,0))
-            activeQtVersion = CppTools::ProjectPart::Qt4Latest;
+        if (qtVersion->qtVersion() < QtSupport::QtVersionNumber(5,0,0))
+            activeQtVersion = CppTools::ProjectPart::Qt4;
         else
             activeQtVersion = CppTools::ProjectPart::Qt5;
     }
diff --git a/src/plugins/git/branchmodel.cpp b/src/plugins/git/branchmodel.cpp
index 047b3ebf99d..35340e0731e 100644
--- a/src/plugins/git/branchmodel.cpp
+++ b/src/plugins/git/branchmodel.cpp
@@ -529,7 +529,7 @@ void BranchModel::checkoutBranch(const QModelIndex &idx)
 
     // No StashGuard since this function for now is only used with clean working dir.
     // If it is ever used from another place, please add StashGuard here
-    m_client->synchronousCheckout(m_workingDirectory, branch);
+    m_client->checkout(m_workingDirectory, branch, GitClient::StashMode::NoStash);
 }
 
 bool BranchModel::branchIsMerged(const QModelIndex &idx)
diff --git a/src/plugins/git/gerrit/gerritplugin.cpp b/src/plugins/git/gerrit/gerritplugin.cpp
index d409f939060..13a49c4903a 100644
--- a/src/plugins/git/gerrit/gerritplugin.cpp
+++ b/src/plugins/git/gerrit/gerritplugin.cpp
@@ -254,7 +254,7 @@ void FetchContext::cherryPick()
 
 void FetchContext::checkout()
 {
-    GitPlugin::client()->stashAndCheckout(m_repository, "FETCH_HEAD");
+    GitPlugin::client()->checkout(m_repository, "FETCH_HEAD");
 }
 
 void FetchContext::terminate()
diff --git a/src/plugins/git/gitclient.cpp b/src/plugins/git/gitclient.cpp
index dbbb45a16a4..eb527339baf 100644
--- a/src/plugins/git/gitclient.cpp
+++ b/src/plugins/git/gitclient.cpp
@@ -1113,21 +1113,22 @@ VcsBaseEditorWidget *GitClient::annotate(
     return editor;
 }
 
-bool GitClient::synchronousCheckout(const QString &workingDirectory,
-                                          const QString &ref,
-                                          QString *errorMessage)
+void GitClient::checkout(const QString &workingDirectory, const QString &ref,
+                         StashMode stashMode)
 {
+    if (stashMode == StashMode::TryStash && !beginStashScope(workingDirectory, "Checkout"))
+        return;
     QStringList arguments = setupCheckoutArguments(workingDirectory, ref);
-    const SynchronousProcessResponse resp = vcsFullySynchronousExec(
-                workingDirectory, arguments, VcsCommand::ExpectRepoChanges);
-    VcsOutputWindow::append(resp.stdOut());
-    if (resp.result == SynchronousProcessResponse::Finished) {
-        updateSubmodulesIfNeeded(workingDirectory, true);
-        return true;
-    } else {
-        msgCannotRun(arguments, workingDirectory, resp.stdErr(), errorMessage);
-        return false;
-    }
+    VcsCommand *command = vcsExec(
+                workingDirectory, arguments, nullptr, true,
+                VcsCommand::ExpectRepoChanges | VcsCommand::ShowSuccessMessage);
+    connect(command, &VcsCommand::finished,
+            this, [this, workingDirectory, stashMode](bool success) {
+        if (stashMode == StashMode::TryStash)
+            endStashScope(workingDirectory);
+        if (success)
+            updateSubmodulesIfNeeded(workingDirectory, true);
+    });
 }
 
 /* method used to setup arguments for checkout, in case user wants to create local branch */
@@ -1358,16 +1359,6 @@ bool GitClient::synchronousCheckoutFiles(const QString &workingDirectory, QStrin
     return true;
 }
 
-bool GitClient::stashAndCheckout(const QString &workingDirectory, const QString &ref)
-{
-    if (!beginStashScope(workingDirectory, "Checkout"))
-        return false;
-    if (!synchronousCheckout(workingDirectory, ref))
-        return false;
-    endStashScope(workingDirectory);
-    return true;
-}
-
 static inline QString msgParentRevisionFailed(const QString &workingDirectory,
                                               const QString &revision,
                                               const QString &why)
@@ -3378,7 +3369,7 @@ GitRemote::GitRemote(const QString &url)
 {
     static const QRegularExpression remotePattern(
                 "^(?:(?<protocol>[^:]+)://)?(?:(?<user>[^@]+)@)?(?<host>[^:/]+)"
-                "(?::(?<port>\\d+))?:?(?<path>/.*)$");
+                "(?::(?<port>\\d+))?:?(?<path>.*)$");
 
     if (url.isEmpty())
         return;
@@ -3403,12 +3394,13 @@ GitRemote::GitRemote(const QString &url)
     if (!match.hasMatch())
         return;
 
+    bool ok  = false;
     protocol = match.captured("protocol");
     userName = match.captured("user");
     host     = match.captured("host");
-    port     = match.captured("port").toUShort();
+    port     = match.captured("port").toUShort(&ok);
     path     = match.captured("path");
-    isValid  = true;
+    isValid  = ok || match.captured("port").isEmpty();
 }
 
 } // namespace Internal
diff --git a/src/plugins/git/gitclient.h b/src/plugins/git/gitclient.h
index 30df75fb907..59b64ae2027 100644
--- a/src/plugins/git/gitclient.h
+++ b/src/plugins/git/gitclient.h
@@ -173,10 +173,9 @@ public:
     bool synchronousCheckoutFiles(const QString &workingDirectory, QStringList files = QStringList(),
                                   QString revision = QString(), QString *errorMessage = nullptr,
                                   bool revertStaging = true);
-    // Checkout ref
-    bool stashAndCheckout(const QString &workingDirectory, const QString &ref);
-    bool synchronousCheckout(const QString &workingDirectory, const QString &ref,
-                             QString *errorMessage = nullptr);
+    enum class StashMode { NoStash, TryStash };
+    void checkout(const QString &workingDirectory, const QString &ref,
+                  StashMode stashMode = StashMode::TryStash);
 
     QStringList setupCheckoutArguments(const QString &workingDirectory, const QString &ref);
     void updateSubmodulesIfNeeded(const QString &workingDirectory, bool prompt);
diff --git a/src/plugins/git/giteditor.cpp b/src/plugins/git/giteditor.cpp
index 2e6746cf646..d4688fa85ff 100644
--- a/src/plugins/git/giteditor.cpp
+++ b/src/plugins/git/giteditor.cpp
@@ -191,7 +191,7 @@ void GitEditorWidget::setPlainText(const QString &text)
 
 void GitEditorWidget::checkoutChange()
 {
-    GitPlugin::client()->stashAndCheckout(sourceWorkingDirectory(), m_currentChange);
+    GitPlugin::client()->checkout(sourceWorkingDirectory(), m_currentChange);
 }
 
 void GitEditorWidget::resetChange(const QByteArray &resetType)
diff --git a/src/plugins/git/gitgrep.cpp b/src/plugins/git/gitgrep.cpp
index 063deb98a25..41f35ea4a80 100644
--- a/src/plugins/git/gitgrep.cpp
+++ b/src/plugins/git/gitgrep.cpp
@@ -82,6 +82,17 @@ public:
         m_directory = parameters.additionalParameters.toString();
     }
 
+    struct Match
+    {
+        Match() = default;
+        Match(int start, int length) :
+            matchStart(start), matchLength(length) {}
+
+        int matchStart = 0;
+        int matchLength = 0;
+        QStringList regexpCapturedTexts;
+    };
+
     void processLine(const QString &line, FileSearchResultList *resultList) const
     {
         if (line.isEmpty())
@@ -97,7 +108,15 @@ public:
         const int textSeparator = line.indexOf(QChar::Null, lineSeparator + 1);
         single.lineNumber = line.mid(lineSeparator + 1, textSeparator - lineSeparator - 1).toInt();
         QString text = line.mid(textSeparator + 1);
-        QVector<QPair<int, int>> matches;
+        QRegularExpression regexp;
+        QVector<Match> matches;
+        if (m_parameters.flags & FindRegularExpression) {
+            const QRegularExpression::PatternOptions patternOptions =
+                    (m_parameters.flags & FindCaseSensitively)
+                    ? QRegularExpression::NoPatternOption : QRegularExpression::CaseInsensitiveOption;
+            regexp.setPattern(m_parameters.text);
+            regexp.setPatternOptions(patternOptions);
+        }
         for (;;) {
             const int matchStart = text.indexOf(boldRed);
             if (matchStart == -1)
@@ -106,23 +125,19 @@ public:
             const int matchEnd = text.indexOf(resetColor, matchTextStart);
             QTC_ASSERT(matchEnd != -1, break);
             const int matchLength = matchEnd - matchTextStart;
-            matches.append(qMakePair(matchStart, matchLength));
-            text = text.left(matchStart) + text.mid(matchTextStart, matchLength)
-                    + text.mid(matchEnd + resetColor.size());
+            Match match(matchStart, matchLength);
+            const QStringRef matchText = text.midRef(matchTextStart, matchLength);
+            if (m_parameters.flags & FindRegularExpression)
+                match.regexpCapturedTexts = regexp.match(matchText).capturedTexts();
+            matches.append(match);
+            text = text.leftRef(matchStart) + matchText + text.midRef(matchEnd + resetColor.size());
         }
         single.matchingLine = text;
 
-        if (m_parameters.flags & FindRegularExpression) {
-            const QRegularExpression::PatternOptions patternOptions =
-                    (m_parameters.flags & QTextDocument::FindCaseSensitively)
-                    ? QRegularExpression::NoPatternOption : QRegularExpression::CaseInsensitiveOption;
-            QRegularExpression regexp(m_parameters.text, patternOptions);
-            QRegularExpressionMatch regexpMatch = regexp.match(line);
-            single.regexpCapturedTexts = regexpMatch.capturedTexts();
-        }
         for (auto match : qAsConst(matches)) {
-            single.matchStart = match.first;
-            single.matchLength = match.second;
+            single.matchStart = match.matchStart;
+            single.matchLength = match.matchLength;
+            single.regexpCapturedTexts = match.regexpCapturedTexts;
             resultList->append(single);
         }
     }
diff --git a/src/plugins/git/gitplugin.cpp b/src/plugins/git/gitplugin.cpp
index 87aac67ef09..35ef47a978c 100644
--- a/src/plugins/git/gitplugin.cpp
+++ b/src/plugins/git/gitplugin.cpp
@@ -861,7 +861,7 @@ void GitPlugin::startChangeRelatedAction(const Id &id)
         m_gitClient->synchronousRevert(workingDirectory, change);
         break;
     case Checkout:
-        m_gitClient->stashAndCheckout(workingDirectory, change);
+        m_gitClient->checkout(workingDirectory, change);
         break;
     default:
         return;
@@ -1552,6 +1552,118 @@ void GitPlugin::testLogResolving()
                             "50a6b54c - Merge branch 'for-junio' of git://bogomips.org/git-svn",
                             "3587b513 - Update draft release notes to 1.8.2");
 }
+
+class RemoteTest {
+public:
+    RemoteTest() = default;
+    explicit RemoteTest(const QString &url): m_url(url) {}
+
+    inline RemoteTest &protocol(const QString &p) { m_protocol = p; return *this; }
+    inline RemoteTest &userName(const QString &u) { m_userName = u; return *this; }
+    inline RemoteTest &host(const QString &h) { m_host = h; return *this; }
+    inline RemoteTest &port(quint16 p) { m_port = p; return *this; }
+    inline RemoteTest &path(const QString &p) { m_path = p; return *this; }
+    inline RemoteTest &isLocal(bool l) { m_isLocal = l; return *this; }
+    inline RemoteTest &isValid(bool v) { m_isValid = v; return *this; }
+
+    const QString m_url;
+    QString m_protocol;
+    QString m_userName;
+    QString m_host;
+    QString m_path;
+    quint16 m_port = 0;
+    bool    m_isLocal = false;
+    bool    m_isValid = true;
+};
+
+} // namespace Internal
+} // namespace Git
+
+Q_DECLARE_METATYPE(Git::Internal::RemoteTest)
+
+namespace Git {
+namespace Internal {
+
+void GitPlugin::testGitRemote_data()
+{
+    QTest::addColumn<RemoteTest>("rt");
+
+    QTest::newRow("http-no-user")
+            << RemoteTest("http://code.qt.io/qt-creator/qt-creator.git")
+               .protocol("http")
+               .host("code.qt.io")
+               .path("/qt-creator/qt-creator.git");
+    QTest::newRow("https-with-port")
+            << RemoteTest("https://code.qt.io:80/qt-creator/qt-creator.git")
+               .protocol("https")
+               .host("code.qt.io")
+               .port(80)
+               .path("/qt-creator/qt-creator.git");
+    QTest::newRow("invalid-port")
+            << RemoteTest("https://code.qt.io:99999/qt-creator/qt-creator.git")
+               .protocol("https")
+               .host("code.qt.io")
+               .path("/qt-creator/qt-creator.git")
+               .isValid(false);
+    QTest::newRow("ssh-user-foo")
+            << RemoteTest("ssh://foo@codereview.qt-project.org:29418/qt-creator/qt-creator.git")
+               .protocol("ssh")
+               .userName("foo")
+               .host("codereview.qt-project.org")
+               .port(29418)
+               .path("/qt-creator/qt-creator.git");
+    QTest::newRow("ssh-github")
+            << RemoteTest("git@github.com:qt-creator/qt-creator.git")
+               .userName("git")
+               .host("github.com")
+               .path("qt-creator/qt-creator.git");
+    QTest::newRow("local-file-protocol")
+            << RemoteTest("file:///tmp/myrepo.git")
+               .protocol("file")
+               .path("/tmp/myrepo.git")
+               .isLocal(true);
+    QTest::newRow("local-absolute-path-unix")
+            << RemoteTest("/tmp/myrepo.git")
+               .protocol("file")
+               .path("/tmp/myrepo.git")
+               .isLocal(true);
+    if (Utils::HostOsInfo::isWindowsHost()) {
+        QTest::newRow("local-absolute-path-unix")
+                << RemoteTest("c:/git/myrepo.git")
+                   .protocol("file")
+                   .path("c:/git/myrepo.git")
+                   .isLocal(true);
+    }
+    QTest::newRow("local-relative-path-children")
+            << RemoteTest("./git/myrepo.git")
+               .protocol("file")
+               .path("./git/myrepo.git")
+               .isLocal(true);
+    QTest::newRow("local-relative-path-parent")
+            << RemoteTest("../myrepo.git")
+               .protocol("file")
+               .path("../myrepo.git")
+               .isLocal(true);
+}
+
+void GitPlugin::testGitRemote()
+{
+    QFETCH(RemoteTest, rt);
+
+    const GitRemote remote = GitRemote(rt.m_url);
+
+    if (!rt.m_isLocal) {
+        // local repositories must exist to be valid, so skip the test
+        QCOMPARE(remote.isValid, rt.m_isValid);
+    }
+
+    QCOMPARE(remote.protocol, rt.m_protocol);
+    QCOMPARE(remote.userName, rt.m_userName);
+    QCOMPARE(remote.host,     rt.m_host);
+    QCOMPARE(remote.port,     rt.m_port);
+    QCOMPARE(remote.path,     rt.m_path);
+}
+
 #endif
 
 } // namespace Internal
diff --git a/src/plugins/git/gitplugin.h b/src/plugins/git/gitplugin.h
index 8722cc058d8..fd334ab89c3 100644
--- a/src/plugins/git/gitplugin.h
+++ b/src/plugins/git/gitplugin.h
@@ -106,6 +106,8 @@ private slots:
     void testDiffFileResolving_data();
     void testDiffFileResolving();
     void testLogResolving();
+    void testGitRemote_data();
+    void testGitRemote();
 #endif
 
 private:
diff --git a/src/plugins/languageclient/languageclient.qbs b/src/plugins/languageclient/languageclient.qbs
index 3b426ceb496..c808ec78139 100644
--- a/src/plugins/languageclient/languageclient.qbs
+++ b/src/plugins/languageclient/languageclient.qbs
@@ -18,6 +18,7 @@ QtcPlugin {
         "baseclient.h",
         "dynamiccapabilities.cpp",
         "dynamiccapabilities.h",
+        "languageclient.qrc",
         "languageclient_global.h",
         "languageclientcodeassist.cpp",
         "languageclientcodeassist.h",
diff --git a/src/plugins/nim/project/nimtoolchain.cpp b/src/plugins/nim/project/nimtoolchain.cpp
index 01147f4fa1f..399814db323 100644
--- a/src/plugins/nim/project/nimtoolchain.cpp
+++ b/src/plugins/nim/project/nimtoolchain.cpp
@@ -77,9 +77,9 @@ bool NimToolChain::isValid() const
     return fi.isExecutable();
 }
 
-ToolChain::PredefinedMacrosRunner NimToolChain::createPredefinedMacrosRunner() const
+ToolChain::MacroInspectionRunner NimToolChain::createMacroInspectionRunner() const
 {
-    return ToolChain::PredefinedMacrosRunner();
+    return ToolChain::MacroInspectionRunner();
 }
 
 Macros NimToolChain::predefinedMacros(const QStringList &) const
@@ -87,9 +87,9 @@ Macros NimToolChain::predefinedMacros(const QStringList &) const
     return Macros();
 }
 
-ToolChain::CompilerFlags NimToolChain::compilerFlags(const QStringList &) const
+LanguageExtensions NimToolChain::languageExtensions(const QStringList &) const
 {
-    return CompilerFlag::NoFlags;
+    return LanguageExtension::None;
 }
 
 WarningFlags NimToolChain::warningFlags(const QStringList &) const
diff --git a/src/plugins/nim/project/nimtoolchain.h b/src/plugins/nim/project/nimtoolchain.h
index 7b25e993def..ae3431a55c7 100644
--- a/src/plugins/nim/project/nimtoolchain.h
+++ b/src/plugins/nim/project/nimtoolchain.h
@@ -40,9 +40,9 @@ public:
     ProjectExplorer::Abi targetAbi() const override;
     bool isValid() const override;
 
-    PredefinedMacrosRunner createPredefinedMacrosRunner() const override;
+    MacroInspectionRunner createMacroInspectionRunner() const override;
     ProjectExplorer::Macros predefinedMacros(const QStringList &flags) const final;
-    CompilerFlags compilerFlags(const QStringList &flags) const final;
+    ProjectExplorer::LanguageExtensions languageExtensions(const QStringList &flags) const final;
     ProjectExplorer::WarningFlags warningFlags(const QStringList &flags) const final;
 
     BuiltInHeaderPathsRunner createBuiltInHeaderPathsRunner() const override;
diff --git a/src/plugins/plugins.qbs b/src/plugins/plugins.qbs
index 4962d159056..6d8d6ad1398 100644
--- a/src/plugins/plugins.qbs
+++ b/src/plugins/plugins.qbs
@@ -20,6 +20,7 @@ Project {
         "classview/classview.qbs",
         "clearcase/clearcase.qbs",
         "cmakeprojectmanager/cmakeprojectmanager.qbs",
+        "compilationdatabaseprojectmanager/compilationdatabaseprojectmanager.qbs",
         "coreplugin/coreplugin.qbs",
         "coreplugin/images/logo/logo.qbs",
         "cpaster/cpaster.qbs",
diff --git a/src/plugins/projectexplorer/abstractmsvctoolchain.cpp b/src/plugins/projectexplorer/abstractmsvctoolchain.cpp
index 4bd77d14627..74816753ba3 100644
--- a/src/plugins/projectexplorer/abstractmsvctoolchain.cpp
+++ b/src/plugins/projectexplorer/abstractmsvctoolchain.cpp
@@ -29,6 +29,7 @@
 #include "projectexplorer.h"
 #include "projectexplorersettings.h"
 #include "taskhub.h"
+#include "toolchaincache.h"
 
 #include <utils/hostosinfo.h>
 #include <utils/qtcprocess.h>
@@ -46,7 +47,7 @@ namespace Internal {
 AbstractMsvcToolChain::AbstractMsvcToolChain(Core::Id typeId, Core::Id l, Detection d,
                                              const Abi &abi,
                                              const QString& vcvarsBat) : ToolChain(typeId, d),
-    m_predefinedMacrosMutex(new QMutex),
+    m_predefinedMacrosCache(std::make_shared<Cache<MacroInspectionReport, 64>>()),
     m_lastEnvironment(Utils::Environment::systemEnvironment()),
     m_headerPathsMutex(new QMutex),
     m_abi(abi),
@@ -57,20 +58,18 @@ AbstractMsvcToolChain::AbstractMsvcToolChain(Core::Id typeId, Core::Id l, Detect
 
 AbstractMsvcToolChain::AbstractMsvcToolChain(Core::Id typeId, Detection d) :
     ToolChain(typeId, d),
+    m_predefinedMacrosCache(std::make_shared<Cache<MacroInspectionReport, 64>>()),
     m_lastEnvironment(Utils::Environment::systemEnvironment())
 { }
 
 AbstractMsvcToolChain::~AbstractMsvcToolChain()
 {
-    delete m_predefinedMacrosMutex;
     delete m_headerPathsMutex;
 }
 
 AbstractMsvcToolChain::AbstractMsvcToolChain(const AbstractMsvcToolChain &other)
     : ToolChain(other),
       m_debuggerCommand(other.m_debuggerCommand),
-      m_predefinedMacrosMutex(new QMutex),
-      m_predefinedMacros(other.m_predefinedMacros),
       m_lastEnvironment(other.m_lastEnvironment),
       m_resultEnvironment(other.m_resultEnvironment),
       m_headerPathsMutex(new QMutex),
@@ -99,65 +98,109 @@ QString AbstractMsvcToolChain::originalTargetTriple() const
             : QLatin1String("i686-pc-windows-msvc");
 }
 
-ToolChain::PredefinedMacrosRunner AbstractMsvcToolChain::createPredefinedMacrosRunner() const
+//
+// We want to detect the language version based on the predefined macros.
+// Unfortunately MSVC does not conform to standard when it comes to the predefined
+// __cplusplus macro - it reports "199711L", even for newer language versions.
+//
+// However:
+//   * For >= Visual Studio 2015 Update 3 predefines _MSVC_LANG which has the proper value
+//     of __cplusplus.
+//     See https://docs.microsoft.com/en-us/cpp/preprocessor/predefined-macros?view=vs-2017
+//   * For >= Visual Studio 2017 Version 15.7 __cplusplus is correct once /Zc:__cplusplus
+//     is provided on the command line. Then __cplusplus == _MSVC_LANG.
+//     See https://blogs.msdn.microsoft.com/vcblog/2018/04/09/msvc-now-correctly-reports-__cplusplus
+//
+// We rely on _MSVC_LANG if possible, otherwise on some hard coded language versions
+// depending on _MSC_VER.
+//
+// For _MSV_VER values, see https://docs.microsoft.com/en-us/cpp/preprocessor/predefined-macros?view=vs-2017.
+//
+LanguageVersion static languageVersionForMsvc(const Core::Id &language, const Macros &macros)
+{
+    int mscVer = -1;
+    QByteArray msvcLang;
+    for (const ProjectExplorer::Macro &macro : macros) {
+        if (macro.key == "_MSVC_LANG")
+            msvcLang = macro.value;
+        if (macro.key == "_MSC_VER")
+            mscVer = macro.value.toInt(nullptr);
+    }
+    QTC_CHECK(mscVer > 0);
+
+    if (language == Constants::CXX_LANGUAGE_ID) {
+        if (!msvcLang.isEmpty()) // >= Visual Studio 2015 Update 3
+            return ToolChain::cxxLanguageVersion(msvcLang);
+        if (mscVer >= 1800) // >= Visual Studio 2013 (12.0)
+            return LanguageVersion::CXX14;
+        if (mscVer >= 1600) // >= Visual Studio 2010 (10.0)
+            return LanguageVersion::CXX11;
+        return LanguageVersion::CXX98;
+    } else if (language == Constants::C_LANGUAGE_ID) {
+        if (mscVer >= 1910) // >= Visual Studio 2017 RTW (15.0)
+            return LanguageVersion::C11;
+        return LanguageVersion::C99;
+    } else {
+        QTC_CHECK(false && "Unexpected toolchain language, assuming latest C++ we support.");
+        return LanguageVersion::LatestCxx;
+    }
+}
+
+bool static hasFlagEffectOnMacros(const QString &flag)
+{
+    if (flag.startsWith("-") || flag.startsWith("/")) {
+        const QString f = flag.mid(1);
+        if (f.startsWith("I"))
+            return false; // Skip include paths
+        if (f.startsWith("w", Qt::CaseInsensitive))
+            return false; // Skip warning options
+    }
+    return true;
+}
+
+ToolChain::MacroInspectionRunner AbstractMsvcToolChain::createMacroInspectionRunner() const
 {
     Utils::Environment env(m_lastEnvironment);
     addToEnvironment(env);
+    std::shared_ptr<Cache<MacroInspectionReport, 64>> macroCache = m_predefinedMacrosCache;
+    const Core::Id lang = language();
 
     // This runner must be thread-safe!
-    return [this, env](const QStringList &cxxflags) {
-        QMutexLocker locker(m_predefinedMacrosMutex);
-        if (m_predefinedMacros.isEmpty())
-            m_predefinedMacros = msvcPredefinedMacros(cxxflags, env);
-        return m_predefinedMacros;
+    return [this, env, macroCache, lang](const QStringList &cxxflags) {
+        const QStringList filteredFlags = Utils::filtered(cxxflags, [](const QString &arg) {
+            return hasFlagEffectOnMacros(arg);
+        });
+
+        const Utils::optional<MacroInspectionReport> cachedMacros = macroCache->check(filteredFlags);
+        if (cachedMacros)
+            return cachedMacros.value();
+
+        const Macros macros = msvcPredefinedMacros(filteredFlags, env);
+
+        const auto report = MacroInspectionReport{macros,
+                                                  languageVersionForMsvc(lang, macros)};
+        macroCache->insert(filteredFlags, report);
+
+        return report;
     };
 }
 
 ProjectExplorer::Macros AbstractMsvcToolChain::predefinedMacros(const QStringList &cxxflags) const
 {
-    return createPredefinedMacrosRunner()(cxxflags);
+    return createMacroInspectionRunner()(cxxflags).macros;
 }
 
-ToolChain::CompilerFlags AbstractMsvcToolChain::compilerFlags(const QStringList &cxxflags) const
+LanguageExtensions AbstractMsvcToolChain::languageExtensions(const QStringList &cxxflags) const
 {
-    CompilerFlags flags(MicrosoftExtensions);
+    LanguageExtensions extensions(LanguageExtension::Microsoft);
     if (cxxflags.contains(QLatin1String("/openmp")))
-        flags |= OpenMP;
+        extensions |= LanguageExtension::OpenMP;
 
     // see http://msdn.microsoft.com/en-us/library/0k0w269d%28v=vs.71%29.aspx
     if (cxxflags.contains(QLatin1String("/Za")))
-        flags &= ~MicrosoftExtensions;
+        extensions &= ~LanguageExtensions(LanguageExtension::Microsoft);
 
-    bool cLanguage = (language() == ProjectExplorer::Constants::C_LANGUAGE_ID);
-
-    switch (m_abi.osFlavor()) {
-    case Abi::WindowsMsvc2010Flavor:
-    case Abi::WindowsMsvc2012Flavor:
-        if (cLanguage)
-            flags |= StandardC99;
-        else
-            flags |= StandardCxx11;
-        break;
-    case Abi::WindowsMsvc2013Flavor:
-    case Abi::WindowsMsvc2015Flavor:
-        if (cLanguage)
-            flags |= StandardC99;
-        else
-            flags |= StandardCxx14;
-        break;
-    case Abi::WindowsMsvc2017Flavor:
-        if (cLanguage)
-            flags |= StandardC11;
-        else if (cxxflags.contains("/std:c++17") || cxxflags.contains("/std:c++latest"))
-            flags |= StandardCxx17;
-        else
-            flags |= StandardCxx14;
-        break;
-    default:
-        break;
-    }
-
-    return flags;
+    return extensions;
 }
 
 /**
@@ -427,6 +470,11 @@ void AbstractMsvcToolChain::inferWarningsForLevel(int warningLevel, WarningFlags
         flags |= WarningFlags::UnusedParams;
 }
 
+void Internal::AbstractMsvcToolChain::toolChainUpdated()
+{
+    m_predefinedMacrosCache->invalidate();
+}
+
 bool AbstractMsvcToolChain::operator ==(const ToolChain &other) const
 {
     if (!ToolChain::operator ==(other))
diff --git a/src/plugins/projectexplorer/abstractmsvctoolchain.h b/src/plugins/projectexplorer/abstractmsvctoolchain.h
index 2979e728cc8..a0836e4dc6c 100644
--- a/src/plugins/projectexplorer/abstractmsvctoolchain.h
+++ b/src/plugins/projectexplorer/abstractmsvctoolchain.h
@@ -26,6 +26,7 @@
 #pragma once
 
 #include "toolchain.h"
+#include "toolchaincache.h"
 #include "abi.h"
 #include "headerpath.h"
 
@@ -53,9 +54,9 @@ public:
 
     QString originalTargetTriple() const override;
 
-    PredefinedMacrosRunner createPredefinedMacrosRunner() const override;
+    MacroInspectionRunner createMacroInspectionRunner() const override;
     Macros predefinedMacros(const QStringList &cxxflags) const override;
-    CompilerFlags compilerFlags(const QStringList &cxxflags) const override;
+    LanguageExtensions languageExtensions(const QStringList &cxxflags) const override;
     WarningFlags warningFlags(const QStringList &cflags) const override;
     BuiltInHeaderPathsRunner createBuiltInHeaderPathsRunner() const override;
     HeaderPaths builtInHeaderPaths(const QStringList &cxxflags,
@@ -92,6 +93,7 @@ protected:
     };
 
     static void inferWarningsForLevel(int warningLevel, WarningFlags &flags);
+    void toolChainUpdated() override;
     virtual Utils::Environment readEnvironmentSetting(const Utils::Environment& env) const = 0;
     // Function must be thread-safe!
     virtual Macros msvcPredefinedMacros(const QStringList cxxflags,
@@ -99,8 +101,9 @@ protected:
 
 
     Utils::FileName m_debuggerCommand;
-    mutable QMutex *m_predefinedMacrosMutex = nullptr;
-    mutable Macros m_predefinedMacros;
+
+    mutable std::shared_ptr<Cache<MacroInspectionReport, 64>> m_predefinedMacrosCache;
+
     mutable Utils::Environment m_lastEnvironment;   // Last checked 'incoming' environment.
     mutable Utils::Environment m_resultEnvironment; // Resulting environment for VC
     mutable QMutex *m_headerPathsMutex = nullptr;
diff --git a/src/plugins/projectexplorer/customtoolchain.cpp b/src/plugins/projectexplorer/customtoolchain.cpp
index f9cb0a81a76..d2c6ed8eea0 100644
--- a/src/plugins/projectexplorer/customtoolchain.cpp
+++ b/src/plugins/projectexplorer/customtoolchain.cpp
@@ -116,12 +116,13 @@ bool CustomToolChain::isValid() const
     return true;
 }
 
-ToolChain::PredefinedMacrosRunner CustomToolChain::createPredefinedMacrosRunner() const
+ToolChain::MacroInspectionRunner CustomToolChain::createMacroInspectionRunner() const
 {
     const Macros theMacros = m_predefinedMacros;
+    const Core::Id lang = language();
 
     // This runner must be thread-safe!
-    return [theMacros](const QStringList &cxxflags){
+    return [theMacros, lang](const QStringList &cxxflags){
         Macros macros = theMacros;
         for (const QString &cxxFlag : cxxflags) {
             if (cxxFlag.startsWith(QLatin1String("-D")))
@@ -130,21 +131,18 @@ ToolChain::PredefinedMacrosRunner CustomToolChain::createPredefinedMacrosRunner(
                 macros.append({cxxFlag.mid(2).trimmed().toUtf8(), MacroType::Undefine});
 
         }
-        return macros;
+        return MacroInspectionReport{macros, ToolChain::languageVersion(lang, macros)};
     };
 }
 
 Macros CustomToolChain::predefinedMacros(const QStringList &cxxflags) const
 {
-    return createPredefinedMacrosRunner()(cxxflags);
+    return createMacroInspectionRunner()(cxxflags).macros;
 }
 
-ToolChain::CompilerFlags CustomToolChain::compilerFlags(const QStringList &cxxflags) const
+LanguageExtensions CustomToolChain::languageExtensions(const QStringList &) const
 {
-    for (const QString &cxx11Flag : m_cxx11Flags)
-        if (cxxflags.contains(cxx11Flag))
-            return StandardCxx11;
-    return NoFlags;
+    return LanguageExtension::None;
 }
 
 WarningFlags CustomToolChain::warningFlags(const QStringList &cxxflags) const
diff --git a/src/plugins/projectexplorer/customtoolchain.h b/src/plugins/projectexplorer/customtoolchain.h
index 23abb2e7301..e9d672ad33d 100644
--- a/src/plugins/projectexplorer/customtoolchain.h
+++ b/src/plugins/projectexplorer/customtoolchain.h
@@ -71,9 +71,9 @@ public:
 
     bool isValid() const override;
 
-    PredefinedMacrosRunner createPredefinedMacrosRunner() const override;
+    MacroInspectionRunner createMacroInspectionRunner() const override;
     Macros predefinedMacros(const QStringList &cxxflags) const override;
-    CompilerFlags compilerFlags(const QStringList &cxxflags) const override;
+    LanguageExtensions languageExtensions(const QStringList &cxxflags) const override;
     WarningFlags warningFlags(const QStringList &cxxflags) const override;
     const Macros &rawPredefinedMacros() const;
     void setPredefinedMacros(const Macros &macros);
diff --git a/src/plugins/projectexplorer/gcctoolchain.cpp b/src/plugins/projectexplorer/gcctoolchain.cpp
index 622b477ca21..390ce5706dd 100644
--- a/src/plugins/projectexplorer/gcctoolchain.cpp
+++ b/src/plugins/projectexplorer/gcctoolchain.cpp
@@ -254,7 +254,7 @@ GccToolChain::GccToolChain(Detection d) :
 
 GccToolChain::GccToolChain(Core::Id typeId, Detection d) :
     ToolChain(typeId, d),
-    m_predefinedMacrosCache(std::make_shared<Cache<QVector<Macro>, 64>>()),
+    m_predefinedMacrosCache(std::make_shared<Cache<MacroInspectionReport, 64>>()),
     m_headerPathsCache(std::make_shared<Cache<HeaderPaths>>())
 { }
 
@@ -302,9 +302,9 @@ QString GccToolChain::defaultDisplayName() const
                                                                   compilerCommand().parentDir().toUserOutput());
 }
 
-ToolChain::CompilerFlags GccToolChain::defaultCompilerFlags() const
+LanguageExtensions GccToolChain::defaultLanguageExtensions() const
 {
-    return CompilerFlags(GnuExtensions);
+    return LanguageExtension::Gnu;
 }
 
 QString GccToolChain::typeDisplayName() const
@@ -385,9 +385,7 @@ static Utils::FileName findLocalCompiler(const Utils::FileName &compilerPath,
     return path.isEmpty() ? compilerPath : path;
 }
 
-Q_GLOBAL_STATIC_WITH_ARGS(const QVector<QByteArray>, unwantedMacros, ({"__cplusplus"}))
-
-ToolChain::PredefinedMacrosRunner GccToolChain::createPredefinedMacrosRunner() const
+ToolChain::MacroInspectionRunner GccToolChain::createMacroInspectionRunner() const
 {
     // Using a clean environment breaks ccache/distcc/etc.
     Environment env = Environment::systemEnvironment();
@@ -396,7 +394,7 @@ ToolChain::PredefinedMacrosRunner GccToolChain::createPredefinedMacrosRunner() c
     const QStringList platformCodeGenFlags = m_platformCodeGenFlags;
     OptionsReinterpreter reinterpretOptions = m_optionsReinterpreter;
     QTC_CHECK(reinterpretOptions);
-    std::shared_ptr<Cache<QVector<Macro>, 64>> macroCache = m_predefinedMacrosCache;
+    std::shared_ptr<Cache<MacroInspectionReport, 64>> macroCache = m_predefinedMacrosCache;
     Core::Id lang = language();
 
     // This runner must be thread-safe!
@@ -436,28 +434,27 @@ ToolChain::PredefinedMacrosRunner GccToolChain::createPredefinedMacrosRunner() c
         }
 
         arguments = reinterpretOptions(arguments);
-        const Utils::optional<QVector<Macro>> cachedMacros = macroCache->check(arguments);
+        const Utils::optional<MacroInspectionReport> cachedMacros = macroCache->check(arguments);
         if (cachedMacros)
             return cachedMacros.value();
 
-        const QVector<Macro> macros
-                = gccPredefinedMacros(findLocalCompiler(compilerCommand, env),
-                                      arguments,
-                                      env.toStringList());
-        const QVector<Macro> filteredMacros = Utils::filtered(macros, [](const Macro &m) {
-            return !unwantedMacros->contains(m.key);
-        });
-        macroCache->insert(arguments, filteredMacros);
+        const Macros macros = gccPredefinedMacros(findLocalCompiler(compilerCommand, env),
+                                                  arguments,
+                                                  env.toStringList());
 
-        qCDebug(gccLog) << "Reporting macros to code model:";
-        for (const Macro &m : filteredMacros) {
+        const auto report = MacroInspectionReport{macros, languageVersion(lang, macros)};
+        macroCache->insert(arguments, report);
+
+        qCDebug(gccLog) << "MacroInspectionReport for code model:";
+        qCDebug(gccLog) << "Language version:" << static_cast<int>(report.languageVersion);
+        for (const Macro &m : macros) {
             qCDebug(gccLog) << compilerCommand.toUserOutput()
                             << (lang == Constants::CXX_LANGUAGE_ID ? ": C++ [" : ": C [")
                             << arguments.join(", ") << "]"
                             << QString::fromUtf8(m.toByteArray());
         }
 
-        return filteredMacros;
+        return report;
     };
 }
 
@@ -472,74 +469,33 @@ ToolChain::PredefinedMacrosRunner GccToolChain::createPredefinedMacrosRunner() c
  */
 ProjectExplorer::Macros GccToolChain::predefinedMacros(const QStringList &cxxflags) const
 {
-    return createPredefinedMacrosRunner()(cxxflags);
+    return createMacroInspectionRunner()(cxxflags).macros;
 }
 
 /**
- * @brief Parses gcc flags -std=*, -fopenmp, -fms-extensions, -ansi.
+ * @brief Parses gcc flags -std=*, -fopenmp, -fms-extensions.
  * @see http://gcc.gnu.org/onlinedocs/gcc/C-Dialect-Options.html
  */
-ToolChain::CompilerFlags GccToolChain::compilerFlags(const QStringList &cxxflags) const
+LanguageExtensions GccToolChain::languageExtensions(const QStringList &cxxflags) const
 {
-    CompilerFlags flags = defaultCompilerFlags();
+    LanguageExtensions extensions = defaultLanguageExtensions();
 
     const QStringList allCxxflags = m_platformCodeGenFlags + cxxflags; // add only cxxflags is empty?
     foreach (const QString &flag, allCxxflags) {
         if (flag.startsWith("-std=")) {
             const QByteArray std = flag.mid(5).toLatin1();
-            if (std == "c++98" || std == "c++03") {
-                flags &= ~CompilerFlags(StandardCxx11 | StandardCxx14 | StandardCxx17 | GnuExtensions);
-                flags |= StandardCxx98;
-            } else if (std == "gnu++98" || std == "gnu++03") {
-                flags &= ~CompilerFlags(StandardCxx11 | StandardCxx14 | StandardCxx17);
-                flags |= GnuExtensions;
-            } else if (std == "c++0x" || std == "c++11") {
-                flags |= StandardCxx11;
-                flags &= ~CompilerFlags(StandardCxx14 | StandardCxx17 | GnuExtensions);
-            } else if (std == "c++14" || std == "c++1y") {
-                flags |= StandardCxx14;
-                flags &= ~CompilerFlags(StandardCxx11 | StandardCxx17 | GnuExtensions);
-            } else if (std == "c++17" || std == "c++1z") {
-                flags |= StandardCxx17;
-                flags &= ~CompilerFlags(StandardCxx11 | StandardCxx14 | GnuExtensions);
-            } else if (std == "gnu++0x" || std == "gnu++11") {
-                flags |= CompilerFlags(StandardCxx11 | GnuExtensions);
-                flags &= ~CompilerFlags(StandardCxx14 | StandardCxx17);
-            } else if (std== "gnu++14" || std == "gnu++1y") {
-                flags |= CompilerFlags(StandardCxx14 | GnuExtensions);
-                flags &= ~CompilerFlags(StandardCxx11 | StandardCxx17);
-            } else if (std== "gnu++17" || std == "gnu++1z") {
-                flags |= CompilerFlags(StandardCxx17 | GnuExtensions);
-                flags &= ~CompilerFlags(StandardCxx11 | StandardCxx14);
-            } else if (std == "c89" || std == "c90"
-                       || std == "iso9899:1990" || std == "iso9899:199409") {
-                flags &= ~CompilerFlags(StandardC99 | StandardC11);
-            } else if (std == "gnu89" || std == "gnu90") {
-                flags &= ~CompilerFlags(StandardC99 | StandardC11);
-                flags |= GnuExtensions;
-            } else if (std == "c99" || std == "c9x"
-                       || std == "iso9899:1999" || std == "iso9899:199x") {
-                flags |= StandardC99;
-                flags &= ~StandardC11;
-            } else if (std == "gnu99" || std == "gnu9x") {
-                flags |= CompilerFlags(StandardC99 | GnuExtensions);
-                flags &= ~StandardC11;
-            } else if (std == "c11" || std == "c1x" || std == "iso9899:2011") {
-                flags |= CompilerFlags(StandardC99 | StandardC11);
-            } else if (std == "gnu11" || std == "gnu1x") {
-                flags |= CompilerFlags(StandardC99 | StandardC11 | GnuExtensions);
-            }
+            if (std.startsWith("gnu"))
+                extensions |= LanguageExtension::Gnu;
+            else
+                extensions &= ~LanguageExtensions(LanguageExtension::Gnu);
         } else if (flag == "-fopenmp") {
-            flags |= OpenMP;
+            extensions |= LanguageExtension::Gnu;
         } else if (flag == "-fms-extensions") {
-            flags |= MicrosoftExtensions;
-        } else if (flag == "-ansi") {
-            flags &= ~CompilerFlags(StandardCxx11 | GnuExtensions
-                                    | StandardC99 | StandardC11);
+            extensions |= LanguageExtension::Microsoft;
         }
     }
 
-    return flags;
+    return extensions;
 }
 
 WarningFlags GccToolChain::warningFlags(const QStringList &cflags) const
@@ -1069,7 +1025,10 @@ QList<ToolChain *> GccToolChainFactory::autoDetectToolChain(const FileName &comp
             return result;
 
         tc->setLanguage(language);
-        tc->m_predefinedMacrosCache->insert(QStringList(), macros);
+        tc->m_predefinedMacrosCache
+            ->insert(QStringList(),
+                     ToolChain::MacroInspectionReport{macros,
+                                                      ToolChain::languageVersion(language, macros)});
         tc->setCompilerCommand(compilerPath);
         tc->setSupportedAbis(detectedAbis.supportedAbis);
         tc->setTargetAbi(abi);
@@ -1134,7 +1093,11 @@ void GccToolChainConfigWidget::applyImpl()
     tc->setDisplayName(displayName); // reset display name
     tc->setPlatformCodeGenFlags(splitString(m_platformCodeGenFlagsLineEdit->text()));
     tc->setPlatformLinkerFlags(splitString(m_platformLinkerFlagsLineEdit->text()));
-    tc->m_predefinedMacrosCache->insert(tc->platformCodeGenFlags(), m_macros);
+    tc->m_predefinedMacrosCache
+        ->insert(tc->platformCodeGenFlags(),
+                 ToolChain::MacroInspectionReport{m_macros,
+                                                  ToolChain::languageVersion(tc->language(),
+                                                                             m_macros)});
 }
 
 void GccToolChainConfigWidget::setFromToolchain()
@@ -1268,15 +1231,15 @@ QString ClangToolChain::makeCommand(const Environment &environment) const
 }
 
 /**
- * @brief Similar to \a GccToolchain::compilerFlags, but recognizes
+ * @brief Similar to \a GccToolchain::languageExtensions, but recognizes
  * "-fborland-extensions".
  */
-ToolChain::CompilerFlags ClangToolChain::compilerFlags(const QStringList &cxxflags) const
+LanguageExtensions ClangToolChain::languageExtensions(const QStringList &cxxflags) const
 {
-    CompilerFlags flags = GccToolChain::compilerFlags(cxxflags);
+    LanguageExtensions extensions = GccToolChain::languageExtensions(cxxflags);
     if (cxxflags.contains("-fborland-extensions"))
-        flags |= BorlandExtensions;
-    return flags;
+        extensions |= LanguageExtension::Borland;
+    return extensions;
 }
 
 WarningFlags ClangToolChain::warningFlags(const QStringList &cflags) const
@@ -1317,9 +1280,9 @@ void ClangToolChain::addToEnvironment(Environment &env) const
     env.unset("PWD");
 }
 
-ToolChain::CompilerFlags ClangToolChain::defaultCompilerFlags() const
+LanguageExtensions ClangToolChain::defaultLanguageExtensions() const
 {
-    return CompilerFlags(GnuExtensions | StandardCxx11);
+    return LanguageExtension::Gnu;
 }
 
 IOutputParser *ClangToolChain::outputParser() const
@@ -1365,12 +1328,12 @@ QList<ToolChain *> ClangToolChainFactory::autoDetect(const QList<ToolChain *> &a
 
     const FileName compilerPath = FileName::fromString(Core::ICore::clangExecutable(CLANG_BINDIR));
     if (!compilerPath.isEmpty()) {
-        tcs.append(autoDetectToolchains(compilerPath.parentDir().appendPath(
-                                            HostOsInfo::withExecutableSuffix("clang++")),
+        const FileName clang = compilerPath.parentDir().appendPath(
+                    HostOsInfo::withExecutableSuffix("clang"));
+        tcs.append(autoDetectToolchains(clang,
                                         hostAbi, Constants::CXX_LANGUAGE_ID,
                                         Constants::CLANG_TOOLCHAIN_TYPEID, alreadyKnown));
-        tcs.append(autoDetectToolchains(compilerPath.parentDir().appendPath(
-                                            HostOsInfo::withExecutableSuffix("clang")),
+        tcs.append(autoDetectToolchains(clang,
                                         hostAbi, Constants::C_LANGUAGE_ID,
                                         Constants::CLANG_TOOLCHAIN_TYPEID, alreadyKnown));
     }
@@ -1510,25 +1473,25 @@ QString LinuxIccToolChain::typeDisplayName() const
 }
 
 /**
- * Similar to \a GccToolchain::compilerFlags, but uses "-openmp" instead of
+ * Similar to \a GccToolchain::languageExtensions, but uses "-openmp" instead of
  * "-fopenmp" and "-fms-dialect[=ver]" instead of "-fms-extensions".
  * @see UNIX manual for "icc"
  */
-ToolChain::CompilerFlags LinuxIccToolChain::compilerFlags(const QStringList &cxxflags) const
+LanguageExtensions LinuxIccToolChain::languageExtensions(const QStringList &cxxflags) const
 {
     QStringList copy = cxxflags;
     copy.removeAll("-fopenmp");
     copy.removeAll("-fms-extensions");
 
-    CompilerFlags flags = GccToolChain::compilerFlags(cxxflags);
+    LanguageExtensions extensions = GccToolChain::languageExtensions(cxxflags);
     if (cxxflags.contains("-openmp"))
-        flags |= OpenMP;
+        extensions |= LanguageExtension::OpenMP;
     if (cxxflags.contains("-fms-dialect")
             || cxxflags.contains("-fms-dialect=8")
             || cxxflags.contains("-fms-dialect=9")
             || cxxflags.contains("-fms-dialect=10"))
-        flags |= MicrosoftExtensions;
-    return flags;
+        extensions |= LanguageExtension::Microsoft;
+    return extensions;
 }
 
 IOutputParser *LinuxIccToolChain::outputParser() const
diff --git a/src/plugins/projectexplorer/gcctoolchain.h b/src/plugins/projectexplorer/gcctoolchain.h
index 3458f634140..13685101fdc 100644
--- a/src/plugins/projectexplorer/gcctoolchain.h
+++ b/src/plugins/projectexplorer/gcctoolchain.h
@@ -28,14 +28,11 @@
 #include "projectexplorer_export.h"
 
 #include "toolchain.h"
+#include "toolchaincache.h"
 #include "abi.h"
 #include "headerpath.h"
 
 #include <utils/fileutils.h>
-#include <utils/optional.h>
-
-#include <QMutex>
-#include <QStringList>
 
 #include <functional>
 #include <memory>
@@ -54,79 +51,6 @@ class LinuxIccToolChainFactory;
 // GccToolChain
 // --------------------------------------------------------------------------
 
-template<class T, int Size = 16>
-class Cache
-{
-public:
-    Cache() { m_cache.reserve(Size); }
-    Cache(const Cache &other) = delete;
-    Cache &operator =(const Cache &other) = delete;
-
-    Cache(Cache &&other)
-    {
-        using std::swap;
-
-        QMutexLocker otherLocker(&other.m_mutex);
-        swap(m_cache, other.m_cache);
-    }
-
-    Cache &operator =(Cache &&other)
-    {
-        using std::swap;
-
-        QMutexLocker locker(&m_mutex);
-        QMutexLocker otherLocker(&other.m_mutex);
-        auto temporay(std::move(other.m_cache)); // Make sure other.m_cache is empty!
-        swap(m_cache, temporay);
-        return *this;
-    }
-
-    void insert(const QStringList &compilerArguments, const T &values)
-    {
-        CacheItem runResults;
-        runResults.first = compilerArguments;
-        runResults.second = values;
-
-        QMutexLocker locker(&m_mutex);
-        if (!checkImpl(compilerArguments)) {
-            if (m_cache.size() < Size) {
-                m_cache.push_back(runResults);
-            } else {
-                std::rotate(m_cache.begin(), std::next(m_cache.begin()), m_cache.end());
-                m_cache.back() = runResults;
-            }
-        }
-    }
-
-    Utils::optional<T> check(const QStringList &compilerArguments)
-    {
-        QMutexLocker locker(&m_mutex);
-        return checkImpl(compilerArguments);
-    }
-
-    void invalidate()
-    {
-        QMutexLocker locker(&m_mutex);
-        m_cache.clear();
-    }
-
-private:
-    Utils::optional<T> checkImpl(const QStringList &compilerArguments)
-    {
-        auto it = std::stable_partition(m_cache.begin(), m_cache.end(), [&](const CacheItem &ci) {
-            return ci.first != compilerArguments;
-        });
-        if (it != m_cache.end())
-            return m_cache.back().second;
-        return {};
-    }
-
-    using CacheItem = QPair<QStringList, T>;
-
-    QMutex m_mutex;
-    QVector<CacheItem> m_cache;
-};
-
 class PROJECTEXPLORER_EXPORT GccToolChain : public ToolChain
 {
 public:
@@ -140,10 +64,10 @@ public:
 
     bool isValid() const override;
 
-    CompilerFlags compilerFlags(const QStringList &cxxflags) const override;
+    LanguageExtensions languageExtensions(const QStringList &cxxflags) const override;
     WarningFlags warningFlags(const QStringList &cflags) const override;
 
-    PredefinedMacrosRunner createPredefinedMacrosRunner() const override;
+    MacroInspectionRunner createMacroInspectionRunner() const override;
     Macros predefinedMacros(const QStringList &cxxflags) const override;
 
     BuiltInHeaderPathsRunner createBuiltInHeaderPathsRunner() const override;
@@ -200,7 +124,7 @@ protected:
     Macros macroCache(const QStringList &allCxxflags) const;
 
     virtual QString defaultDisplayName() const;
-    virtual CompilerFlags defaultCompilerFlags() const;
+    virtual LanguageExtensions defaultLanguageExtensions() const;
 
     virtual DetectedAbisResult detectSupportedAbis() const;
     virtual QString detectVersion() const;
@@ -253,7 +177,7 @@ private:
     mutable HeaderPaths m_headerPaths;
     mutable QString m_version;
 
-    mutable std::shared_ptr<Cache<QVector<Macro>, 64>> m_predefinedMacrosCache;
+    mutable std::shared_ptr<Cache<MacroInspectionReport, 64>> m_predefinedMacrosCache;
     mutable std::shared_ptr<Cache<HeaderPaths>> m_headerPathsCache;
     mutable ExtraHeaderPathsFunction m_extraHeaderPathsFunction = [](HeaderPaths &) {};
 
@@ -273,7 +197,7 @@ public:
     QString typeDisplayName() const override;
     QString makeCommand(const Utils::Environment &environment) const override;
 
-    CompilerFlags compilerFlags(const QStringList &cxxflags) const override;
+    LanguageExtensions languageExtensions(const QStringList &cxxflags) const override;
     WarningFlags warningFlags(const QStringList &cflags) const override;
 
     IOutputParser *outputParser() const override;
@@ -284,7 +208,7 @@ public:
     void addToEnvironment(Utils::Environment &env) const override;
 
 protected:
-    CompilerFlags defaultCompilerFlags() const override;
+    LanguageExtensions defaultLanguageExtensions() const override;
 
 private:
     friend class Internal::ClangToolChainFactory;
@@ -321,7 +245,7 @@ class PROJECTEXPLORER_EXPORT LinuxIccToolChain : public GccToolChain
 public:
     QString typeDisplayName() const override;
 
-    CompilerFlags compilerFlags(const QStringList &cxxflags) const override;
+    LanguageExtensions languageExtensions(const QStringList &cxxflags) const override;
     IOutputParser *outputParser() const override;
 
     ToolChain *clone() const override;
diff --git a/src/plugins/projectexplorer/jsonwizard/jsonwizardfactory.cpp b/src/plugins/projectexplorer/jsonwizard/jsonwizardfactory.cpp
index 1ef81e7d455..3a01d9e0454 100644
--- a/src/plugins/projectexplorer/jsonwizard/jsonwizardfactory.cpp
+++ b/src/plugins/projectexplorer/jsonwizard/jsonwizardfactory.cpp
@@ -314,6 +314,24 @@ JsonWizardFactory *JsonWizardFactory::createWizardFactory(const QVariantMap &dat
     return factory;
 }
 
+static QStringList environmentTemplatesPaths()
+{
+    QStringList paths;
+
+    QString envTempPath = QString::fromLocal8Bit(qgetenv("QTCREATOR_TEMPLATES_PATH"));
+
+    if (!envTempPath.isEmpty()) {
+        for (const QString &path : envTempPath
+             .split(Utils::HostOsInfo::pathListSeparator(), QString::SkipEmptyParts)) {
+            QString canonicalPath = QDir(path).canonicalPath();
+            if (!canonicalPath.isEmpty() && !paths.contains(canonicalPath))
+                paths.append(canonicalPath);
+        }
+    }
+
+    return paths;
+}
+
 Utils::FileNameList &JsonWizardFactory::searchPaths()
 {
     static Utils::FileNameList m_searchPaths = Utils::FileNameList()
@@ -321,6 +339,9 @@ Utils::FileNameList &JsonWizardFactory::searchPaths()
                                            QLatin1String(WIZARD_PATH))
             << Utils::FileName::fromString(Core::ICore::resourcePath() + QLatin1Char('/') +
                                            QLatin1String(WIZARD_PATH));
+    for (const QString &environmentTemplateDirName : environmentTemplatesPaths())
+        m_searchPaths << Utils::FileName::fromString(environmentTemplateDirName);
+
     return m_searchPaths;
 }
 
diff --git a/src/plugins/projectexplorer/language.h b/src/plugins/projectexplorer/language.h
new file mode 100644
index 00000000000..5946553a6dd
--- /dev/null
+++ b/src/plugins/projectexplorer/language.h
@@ -0,0 +1,65 @@
+/****************************************************************************
+**
+** Copyright (C) 2018 The Qt Company Ltd.
+** Contact: https://www.qt.io/licensing/
+**
+** This file is part of Qt Creator.
+**
+** Commercial License Usage
+** Licensees holding valid commercial Qt licenses may use this file in
+** accordance with the commercial license agreement provided with the
+** Software or, alternatively, in accordance with the terms contained in
+** a written agreement between you and The Qt Company. For licensing terms
+** and conditions see https://www.qt.io/terms-conditions. For further
+** information use the contact form at https://www.qt.io/contact-us.
+**
+** GNU General Public License Usage
+** Alternatively, this file may be used under the terms of the GNU
+** General Public License version 3 as published by the Free Software
+** Foundation with exceptions as appearing in the file LICENSE.GPL3-EXCEPT
+** included in the packaging of this file. Please review the following
+** information to ensure the GNU General Public License requirements will
+** be met: https://www.gnu.org/licenses/gpl-3.0.html.
+**
+****************************************************************************/
+
+#pragma once
+
+#include <QFlags>
+
+namespace ProjectExplorer {
+
+enum class LanguageVersion {
+    C89,
+    C99,
+    C11,
+    C18,
+    LatestC = C18,
+    CXX98,
+    CXX03,
+    CXX11,
+    CXX14,
+    CXX17,
+    CXX2a,
+    LatestCxx = CXX2a,
+};
+
+enum class LanguageExtension {
+    None       = 0,
+
+    Gnu        = 1 << 0,
+    Microsoft  = 1 << 1,
+    Borland    = 1 << 2,
+    OpenMP     = 1 << 3,
+    ObjectiveC = 1 << 4,
+
+    All = Gnu
+        | Microsoft
+        | Borland
+        | OpenMP
+        | ObjectiveC
+};
+
+Q_DECLARE_FLAGS(LanguageExtensions, LanguageExtension)
+
+} // namespace ProjectExplorer
diff --git a/src/plugins/projectexplorer/msvctoolchain.cpp b/src/plugins/projectexplorer/msvctoolchain.cpp
index 765dc86d384..50c3a9d369f 100644
--- a/src/plugins/projectexplorer/msvctoolchain.cpp
+++ b/src/plugins/projectexplorer/msvctoolchain.cpp
@@ -334,6 +334,7 @@ static QByteArray msvcCompilationFile()
         "__CLR_VER",
         "_CMMN_INTRIN_FUNC",
         "_CONTROL_FLOW_GUARD",
+        "__cplusplus",
         "__cplusplus_cli",
         "__cplusplus_winrt",
         "_CPPLIB_VER",
@@ -469,8 +470,6 @@ Macros MsvcToolChain::msvcPredefinedMacros(const QStringList cxxflags,
             predefinedMacros.append(Macro::fromKeyValue(define));
         } else if (arg.startsWith(QLatin1String("/U"))) {
             predefinedMacros.append({arg.mid(2).toLocal8Bit(), ProjectExplorer::MacroType::Undefine});
-        } else if (arg.startsWith(QLatin1String("-I"))) {
-            // Include paths should not have any effect on defines
         } else {
             toProcess.append(arg);
         }
diff --git a/src/plugins/projectexplorer/projectexplorer.cpp b/src/plugins/projectexplorer/projectexplorer.cpp
index 34d52e1b782..65981dbe28e 100644
--- a/src/plugins/projectexplorer/projectexplorer.cpp
+++ b/src/plugins/projectexplorer/projectexplorer.cpp
@@ -210,8 +210,6 @@ const char OPENFILE[]             = "ProjectExplorer.OpenFile";
 const char SEARCHONFILESYSTEM[]   = "ProjectExplorer.SearchOnFileSystem";
 const char SHOWINGRAPHICALSHELL[] = "ProjectExplorer.ShowInGraphicalShell";
 const char OPENTERMINALHERE[]     = "ProjectExplorer.OpenTerminalHere";
-const char OPENTERMINALHEREBUILD[]= "ProjectExplorer.OpenTerminalHereBuildEnv";
-const char OPENTERMINALHERERUN[]  = "ProjectExplorer.OpenTerminalHereRunEnv";
 const char DUPLICATEFILE[]        = "ProjectExplorer.DuplicateFile";
 const char DELETEFILE[]           = "ProjectExplorer.DeleteFile";
 const char DIFFFILE[]             = "ProjectExplorer.DiffFile";
@@ -883,11 +881,13 @@ bool ProjectExplorerPlugin::initialize(const QStringList &arguments, QString *er
     dd->m_openTerminalHereBuildEnv = new QAction(tr("Build Environment"), this);
     dd->m_openTerminalHereRunEnv = new QAction(tr("Run Environment"), this);
 #if !defined(Q_OS_UNIX) || QT_VERSION >= QT_VERSION_CHECK(5, 10, 0)
-    cmd = ActionManager::registerAction(dd->m_openTerminalHereBuildEnv, Constants::OPENTERMINALHEREBUILD,
+    cmd = ActionManager::registerAction(dd->m_openTerminalHereBuildEnv,
+                                        "ProjectExplorer.OpenTerminalHereBuildEnv",
                                         projecTreeContext);
     dd->m_openTerminalMenu->addAction(dd->m_openTerminalHereBuildEnv);
 
-    cmd = ActionManager::registerAction(dd->m_openTerminalHereRunEnv, Constants::OPENTERMINALHERERUN,
+    cmd = ActionManager::registerAction(dd->m_openTerminalHereRunEnv,
+                                        "ProjectExplorer.OpenTerminalHereRunEnv",
                                         projecTreeContext);
     dd->m_openTerminalMenu->addAction(dd->m_openTerminalHereRunEnv);
 #endif
diff --git a/src/plugins/projectexplorer/projectexplorer.pro b/src/plugins/projectexplorer/projectexplorer.pro
index 8e21d9a0dd2..adb2d74e377 100644
--- a/src/plugins/projectexplorer/projectexplorer.pro
+++ b/src/plugins/projectexplorer/projectexplorer.pro
@@ -89,6 +89,7 @@ HEADERS += projectexplorer.h \
     projectmodels.h \
     currentprojectfind.h \
     toolchain.h \
+    toolchaincache.h \
     toolchainconfigwidget.h \
     toolchainmanager.h \
     toolchainoptionspage.h \
diff --git a/src/plugins/projectexplorer/projectexplorer.qbs b/src/plugins/projectexplorer/projectexplorer.qbs
index 58646326fab..148d9f3057e 100644
--- a/src/plugins/projectexplorer/projectexplorer.qbs
+++ b/src/plugins/projectexplorer/projectexplorer.qbs
@@ -145,6 +145,7 @@ Project {
                 "taskmodel.cpp", "taskmodel.h",
                 "taskwindow.cpp", "taskwindow.h",
                 "toolchain.cpp", "toolchain.h",
+                "toolchaincache.h",
                 "toolchainconfigwidget.cpp", "toolchainconfigwidget.h",
                 "toolchainmanager.cpp", "toolchainmanager.h",
                 "toolchainoptionspage.cpp", "toolchainoptionspage.h",
diff --git a/src/plugins/projectexplorer/toolchain.cpp b/src/plugins/projectexplorer/toolchain.cpp
index e0c1b113a86..a3f875726ec 100644
--- a/src/plugins/projectexplorer/toolchain.cpp
+++ b/src/plugins/projectexplorer/toolchain.cpp
@@ -286,6 +286,65 @@ bool ToolChain::fromMap(const QVariantMap &data)
     return true;
 }
 
+static long toLanguageVersionAsLong(QByteArray dateAsByteArray)
+{
+    dateAsByteArray.chop(1); // Strip 'L'.
+    return dateAsByteArray.toLong(nullptr);
+}
+
+LanguageVersion ToolChain::cxxLanguageVersion(const QByteArray &cplusplusMacroValue)
+{
+    const long version = toLanguageVersionAsLong(cplusplusMacroValue);
+
+    if (version > 201703L)
+        return LanguageVersion::LatestCxx;
+    if (version > 201402L)
+        return LanguageVersion::CXX17;
+    if (version > 201103L)
+        return LanguageVersion::CXX14;
+    if (version == 201103L)
+        return LanguageVersion::CXX11;
+
+    return LanguageVersion::CXX03;
+}
+
+LanguageVersion ToolChain::languageVersion(const Core::Id &language, const Macros &macros)
+{
+    if (language == Constants::CXX_LANGUAGE_ID) {
+        for (const ProjectExplorer::Macro &macro : macros) {
+            if (macro.key == "__cplusplus") // Check for the C++ identifying macro
+                return cxxLanguageVersion(macro.value);
+        }
+
+        QTC_CHECK(false && "__cplusplus is not predefined, assuming latest C++ we support.");
+        return LanguageVersion::LatestCxx;
+    } else if (language == Constants::C_LANGUAGE_ID) {
+        for (const ProjectExplorer::Macro &macro : macros) {
+            if (macro.key == "__STDC_VERSION__") {
+                const long version = toLanguageVersionAsLong(macro.value);
+
+                if (version > 201710L)
+                    return LanguageVersion::LatestC;
+                if (version > 201112L)
+                    return LanguageVersion::C18;
+                if (version > 199901L)
+                    return LanguageVersion::C11;
+                if (version > 199409L)
+                    return LanguageVersion::C99;
+
+                return LanguageVersion::C89;
+            }
+        }
+
+        // The __STDC_VERSION__ macro was introduced after C89.
+        // We haven't seen it, so it must be C89.
+        return LanguageVersion::C89;
+    } else {
+        QTC_CHECK(false && "Unexpected toolchain language, assuming latest C++ we support.");
+        return LanguageVersion::LatestCxx;
+    }
+}
+
 /*!
     Used by the tool chain kit information to validate the kit.
 */
diff --git a/src/plugins/projectexplorer/toolchain.h b/src/plugins/projectexplorer/toolchain.h
index fcc7e93d062..1976b0925b6 100644
--- a/src/plugins/projectexplorer/toolchain.h
+++ b/src/plugins/projectexplorer/toolchain.h
@@ -29,6 +29,7 @@
 #include "projectexplorer_global.h"
 
 #include "headerpath.h"
+#include "language.h"
 #include "projectmacro.h"
 
 #include <coreplugin/id.h>
@@ -107,28 +108,19 @@ public:
 
     virtual bool isValid() const = 0;
 
-    enum CompilerFlag {
-        NoFlags = 0,
-        StandardCxx11 = 0x1,
-        StandardC99 = 0x2,
-        StandardC11 = 0x4,
-        GnuExtensions = 0x8,
-        MicrosoftExtensions = 0x10,
-        BorlandExtensions = 0x20,
-        OpenMP = 0x40,
-        ObjectiveC = 0x80,
-        StandardCxx14 = 0x100,
-        StandardCxx17 = 0x200,
-        StandardCxx98 = 0x400,
-    };
-    Q_DECLARE_FLAGS(CompilerFlags, CompilerFlag)
-
-    virtual CompilerFlags compilerFlags(const QStringList &cxxflags) const = 0;
+    virtual LanguageExtensions languageExtensions(const QStringList &cxxflags) const = 0;
     virtual WarningFlags warningFlags(const QStringList &cflags) const = 0;
 
-    // A PredefinedMacrosRunner is created in the ui thread and runs in another thread.
-    using PredefinedMacrosRunner = std::function<Macros(const QStringList &cxxflags)>;
-    virtual PredefinedMacrosRunner createPredefinedMacrosRunner() const = 0;
+    class MacroInspectionReport
+    {
+    public:
+        Macros macros;
+        LanguageVersion languageVersion;
+    };
+
+    // A MacroInspectionRunner is created in the ui thread and runs in another thread.
+    using MacroInspectionRunner = std::function<MacroInspectionReport(const QStringList &cxxflags)>;
+    virtual MacroInspectionRunner createMacroInspectionRunner() const = 0;
     virtual Macros predefinedMacros(const QStringList &cxxflags) const = 0;
 
     // A BuiltInHeaderPathsRunner is created in the ui thread and runs in another thread.
@@ -157,6 +149,8 @@ public:
     virtual QList<Task> validateKit(const Kit *k) const;
 
     void setLanguage(Core::Id language);
+    static LanguageVersion cxxLanguageVersion(const QByteArray &cplusplusMacroValue);
+    static LanguageVersion languageVersion(const Core::Id &language, const Macros &macros);
 
 protected:
     explicit ToolChain(Core::Id typeId, Detection d);
diff --git a/src/plugins/projectexplorer/toolchaincache.h b/src/plugins/projectexplorer/toolchaincache.h
new file mode 100644
index 00000000000..154c09162f8
--- /dev/null
+++ b/src/plugins/projectexplorer/toolchaincache.h
@@ -0,0 +1,110 @@
+/****************************************************************************
+**
+** Copyright (C) 2018 The Qt Company Ltd.
+** Contact: https://www.qt.io/licensing/
+**
+** This file is part of Qt Creator.
+**
+** Commercial License Usage
+** Licensees holding valid commercial Qt licenses may use this file in
+** accordance with the commercial license agreement provided with the
+** Software or, alternatively, in accordance with the terms contained in
+** a written agreement between you and The Qt Company. For licensing terms
+** and conditions see https://www.qt.io/terms-conditions. For further
+** information use the contact form at https://www.qt.io/contact-us.
+**
+** GNU General Public License Usage
+** Alternatively, this file may be used under the terms of the GNU
+** General Public License version 3 as published by the Free Software
+** Foundation with exceptions as appearing in the file LICENSE.GPL3-EXCEPT
+** included in the packaging of this file. Please review the following
+** information to ensure the GNU General Public License requirements will
+** be met: https://www.gnu.org/licenses/gpl-3.0.html.
+**
+****************************************************************************/
+
+#pragma once
+
+#include <QMutex>
+#include <QMutexLocker>
+#include <QStringList>
+#include <QVector>
+
+#include <utils/optional.h>
+
+namespace ProjectExplorer {
+
+template<class T, int Size = 16>
+class Cache
+{
+public:
+    Cache() { m_cache.reserve(Size); }
+    Cache(const Cache &other) = delete;
+    Cache &operator =(const Cache &other) = delete;
+
+    Cache(Cache &&other)
+    {
+        using std::swap;
+
+        QMutexLocker otherLocker(&other.m_mutex);
+        swap(m_cache, other.m_cache);
+    }
+
+    Cache &operator =(Cache &&other)
+    {
+        using std::swap;
+
+        QMutexLocker locker(&m_mutex);
+        QMutexLocker otherLocker(&other.m_mutex);
+        auto temporay(std::move(other.m_cache)); // Make sure other.m_cache is empty!
+        swap(m_cache, temporay);
+        return *this;
+    }
+
+    void insert(const QStringList &compilerArguments, const T &values)
+    {
+        CacheItem runResults;
+        runResults.first = compilerArguments;
+        runResults.second = values;
+
+        QMutexLocker locker(&m_mutex);
+        if (!checkImpl(compilerArguments)) {
+            if (m_cache.size() < Size) {
+                m_cache.push_back(runResults);
+            } else {
+                std::rotate(m_cache.begin(), std::next(m_cache.begin()), m_cache.end());
+                m_cache.back() = runResults;
+            }
+        }
+    }
+
+    Utils::optional<T> check(const QStringList &compilerArguments)
+    {
+        QMutexLocker locker(&m_mutex);
+        return checkImpl(compilerArguments);
+    }
+
+    void invalidate()
+    {
+        QMutexLocker locker(&m_mutex);
+        m_cache.clear();
+    }
+
+private:
+    Utils::optional<T> checkImpl(const QStringList &compilerArguments)
+    {
+        auto it = std::stable_partition(m_cache.begin(), m_cache.end(), [&](const CacheItem &ci) {
+            return ci.first != compilerArguments;
+        });
+        if (it != m_cache.end())
+            return m_cache.back().second;
+        return {};
+    }
+
+    using CacheItem = QPair<QStringList, T>;
+
+    QMutex m_mutex;
+    QVector<CacheItem> m_cache;
+};
+
+} // namespace ProjectExplorer
diff --git a/src/plugins/projectexplorer/toolchainsettingsaccessor.cpp b/src/plugins/projectexplorer/toolchainsettingsaccessor.cpp
index 409812440f0..80d280a1227 100644
--- a/src/plugins/projectexplorer/toolchainsettingsaccessor.cpp
+++ b/src/plugins/projectexplorer/toolchainsettingsaccessor.cpp
@@ -308,9 +308,9 @@ public:
     QString typeDisplayName() const override { return QString("Test Tool Chain"); }
     Abi targetAbi() const override { return Abi::hostAbi(); }
     bool isValid() const override { return m_valid; }
-    PredefinedMacrosRunner createPredefinedMacrosRunner() const override { return PredefinedMacrosRunner(); }
+    MacroInspectionRunner createMacroInspectionRunner() const override { return MacroInspectionRunner(); }
     Macros predefinedMacros(const QStringList &cxxflags) const override { Q_UNUSED(cxxflags); return Macros(); }
-    CompilerFlags compilerFlags(const QStringList &cxxflags) const override { Q_UNUSED(cxxflags); return NoFlags; }
+    LanguageExtensions languageExtensions(const QStringList &cxxflags) const override { Q_UNUSED(cxxflags); return LanguageExtension::None; }
     WarningFlags warningFlags(const QStringList &cflags) const override { Q_UNUSED(cflags); return WarningFlags::NoWarnings; }
     BuiltInHeaderPathsRunner createBuiltInHeaderPathsRunner() const override { return BuiltInHeaderPathsRunner(); }
     HeaderPaths builtInHeaderPaths(const QStringList &cxxflags, const FileName &sysRoot) const override
diff --git a/src/plugins/projectexplorer/userfileaccessor.cpp b/src/plugins/projectexplorer/userfileaccessor.cpp
index a20000ea792..e47e9a2dc7c 100644
--- a/src/plugins/projectexplorer/userfileaccessor.cpp
+++ b/src/plugins/projectexplorer/userfileaccessor.cpp
@@ -152,47 +152,6 @@ Q_DECLARE_TYPEINFO(HandlerNode, Q_MOVABLE_TYPE);
 
 QT_END_NAMESPACE
 
-static HandlerNode buildHandlerNodes(const char * const **keys)
-{
-    HandlerNode ret;
-    while (const char *rname = *(*keys)++) {
-        QString name = QLatin1String(rname);
-        if (name.endsWith('.')) {
-            HandlerNode sub = buildHandlerNodes(keys);
-            foreach (const QString &key, name.split('|'))
-                ret.children.insert(key, sub);
-        } else {
-            ret.strings.insert(name);
-        }
-    }
-    return ret;
-}
-
-static QVariantMap processHandlerNodes(const HandlerNode &node, const QVariantMap &map,
-                                       QVariant (*handler)(const QVariant &var))
-{
-    QVariantMap result;
-    QMapIterator<QString, QVariant> it(map);
-    while (it.hasNext()) {
-        it.next();
-        const QString &key = it.key();
-        if (node.strings.contains(key)) {
-            result.insert(key, handler(it.value()));
-            goto handled;
-        }
-        if (it.value().type() == QVariant::Map)
-            for (QHash<QString, HandlerNode>::ConstIterator subit = node.children.constBegin();
-                 subit != node.children.constEnd(); ++subit)
-                if (key.startsWith(subit.key())) {
-                    result.insert(key, processHandlerNodes(subit.value(), it.value().toMap(), handler));
-                    goto handled;
-                }
-        result.insert(key, it.value());
-      handled: ;
-    }
-    return result;
-}
-
 // --------------------------------------------------------------------
 // Helpers:
 // --------------------------------------------------------------------
diff --git a/src/plugins/qbsprojectmanager/qbsproject.cpp b/src/plugins/qbsprojectmanager/qbsproject.cpp
index 1e07625be3a..7981547ab37 100644
--- a/src/plugins/qbsprojectmanager/qbsproject.cpp
+++ b/src/plugins/qbsprojectmanager/qbsproject.cpp
@@ -915,10 +915,8 @@ void QbsProject::updateCppCodeModel()
 
     CppTools::ProjectPart::QtVersion qtVersionFromKit = CppTools::ProjectPart::NoQt;
     if (qtVersion) {
-        if (qtVersion->qtVersion() <= QtSupport::QtVersionNumber(4,8,6))
-            qtVersionFromKit = CppTools::ProjectPart::Qt4_8_6AndOlder;
-        else if (qtVersion->qtVersion() < QtSupport::QtVersionNumber(5,0,0))
-            qtVersionFromKit = CppTools::ProjectPart::Qt4Latest;
+        if (qtVersion->qtVersion() < QtSupport::QtVersionNumber(5,0,0))
+            qtVersionFromKit = CppTools::ProjectPart::Qt4;
         else
             qtVersionFromKit = CppTools::ProjectPart::Qt5;
     }
diff --git a/src/plugins/qmakeprojectmanager/qmakeproject.cpp b/src/plugins/qmakeprojectmanager/qmakeproject.cpp
index e825d600a2a..25477977806 100644
--- a/src/plugins/qmakeprojectmanager/qmakeproject.cpp
+++ b/src/plugins/qmakeprojectmanager/qmakeproject.cpp
@@ -277,10 +277,8 @@ void QmakeProject::updateCppCodeModel()
     QtSupport::BaseQtVersion *qtVersion = QtSupport::QtKitInformation::qtVersion(k);
     ProjectPart::QtVersion qtVersionForPart = ProjectPart::NoQt;
     if (qtVersion) {
-        if (qtVersion->qtVersion() <= QtSupport::QtVersionNumber(4,8,6))
-            qtVersionForPart = ProjectPart::Qt4_8_6AndOlder;
-        else if (qtVersion->qtVersion() < QtSupport::QtVersionNumber(5,0,0))
-            qtVersionForPart = ProjectPart::Qt4Latest;
+        if (qtVersion->qtVersion() < QtSupport::QtVersionNumber(5,0,0))
+            qtVersionForPart = ProjectPart::Qt4;
         else
             qtVersionForPart = ProjectPart::Qt5;
     }
diff --git a/src/plugins/qtsupport/qscxmlcgenerator.cpp b/src/plugins/qtsupport/qscxmlcgenerator.cpp
index 309113322a1..d015d9d445f 100644
--- a/src/plugins/qtsupport/qscxmlcgenerator.cpp
+++ b/src/plugins/qtsupport/qscxmlcgenerator.cpp
@@ -38,7 +38,7 @@ using namespace ProjectExplorer;
 
 namespace QtSupport {
 
-static QLoggingCategory log("qtc.qsxmlcgenerator");
+static QLoggingCategory log("qtc.qscxmlcgenerator");
 static const char TaskCategory[] = "Task.Category.ExtraCompiler.QScxmlc";
 
 QScxmlcGenerator::QScxmlcGenerator(const Project *project,
diff --git a/src/plugins/silversearcher/findinfilessilversearcher.cpp b/src/plugins/silversearcher/findinfilessilversearcher.cpp
index a986df14580..3c8f19bc487 100644
--- a/src/plugins/silversearcher/findinfilessilversearcher.cpp
+++ b/src/plugins/silversearcher/findinfilessilversearcher.cpp
@@ -119,7 +119,15 @@ void runSilverSeacher(FutureInterfaceType &fi, FileFindParameters parameters)
     process.start("ag", arguments);
     if (process.waitForFinished()) {
         typedef QList<FileSearchResult> FileSearchResultList;
-        SilverSearcher::SilverSearcherOutputParser parser(process.readAll());
+        QRegularExpression regexp;
+        if (parameters.flags & FindRegularExpression) {
+            const QRegularExpression::PatternOptions patternOptions =
+                    (parameters.flags & FindCaseSensitively)
+                    ? QRegularExpression::NoPatternOption : QRegularExpression::CaseInsensitiveOption;
+            regexp.setPattern(parameters.text);
+            regexp.setPatternOptions(patternOptions);
+        }
+        SilverSearcher::SilverSearcherOutputParser parser(process.readAll(), regexp);
         FileSearchResultList items = parser.parse();
         if (!items.isEmpty())
             fi.reportResult(items);
@@ -134,7 +142,6 @@ namespace SilverSearcher {
 
 FindInFilesSilverSearcher::FindInFilesSilverSearcher(QObject *parent)
     : SearchEngine(parent),
-      m_widget(0),
       m_path("ag"),
       m_toolName("SilverSearcher")
 {
@@ -190,7 +197,7 @@ QFuture<FileSearchResultList> FindInFilesSilverSearcher::executeSearch(
 IEditor *FindInFilesSilverSearcher::openEditor(const SearchResultItem & /*item*/,
                                                const FileFindParameters & /*parameters*/)
 {
-    return 0;
+    return nullptr;
 }
 
 void FindInFilesSilverSearcher::readSettings(QSettings * /*settings*/)
diff --git a/src/plugins/silversearcher/silversearcheroutputparser.cpp b/src/plugins/silversearcher/silversearcheroutputparser.cpp
index cbc82c5632f..88ec7cdde05 100644
--- a/src/plugins/silversearcher/silversearcheroutputparser.cpp
+++ b/src/plugins/silversearcher/silversearcheroutputparser.cpp
@@ -30,10 +30,12 @@
 namespace SilverSearcher {
 
 SilverSearcherOutputParser::SilverSearcherOutputParser(
-        const QByteArray &output)
+        const QByteArray &output, const QRegularExpression &regexp)
     : output(output)
+    , regexp(regexp)
     , outputSize(output.size())
 {
+    hasRegexp = !regexp.pattern().isEmpty();
 }
 
 QList<Utils::FileSearchResult> SilverSearcherOutputParser::parse()
@@ -102,6 +104,13 @@ bool SilverSearcherOutputParser::parseMatchLength()
 int SilverSearcherOutputParser::parseMatches()
 {
     int matches = 1;
+    const int colon = output.indexOf(':', index);
+    QByteArray text;
+    if (colon != -1) {
+        const int textStart = colon + 1;
+        const int newline = output.indexOf('\n', textStart);
+        text = output.mid(textStart, newline >= 0 ? newline - textStart : -1);
+    }
     while (index < outputSize && output[index] != ':') {
         if (output[index] == ',') {
             ++matches;
@@ -109,6 +118,10 @@ int SilverSearcherOutputParser::parseMatches()
         }
         parseMatchIndex();
         parseMatchLength();
+        if (hasRegexp) {
+            const QString part = QString::fromUtf8(text.mid(item.matchStart, item.matchLength));
+            item.regexpCapturedTexts = regexp.match(part).capturedTexts();
+        }
         items << item;
     }
 
diff --git a/src/plugins/silversearcher/silversearcheroutputparser.h b/src/plugins/silversearcher/silversearcheroutputparser.h
index fd96253427a..1bf0af4685a 100644
--- a/src/plugins/silversearcher/silversearcheroutputparser.h
+++ b/src/plugins/silversearcher/silversearcheroutputparser.h
@@ -28,15 +28,18 @@
 #include <coreplugin/find/searchresultwindow.h>
 #include <utils/filesearch.h>
 
-#include <QList>
 #include <QByteArray>
+#include <QList>
+#include <QRegularExpression>
 
 namespace SilverSearcher {
 
 class SilverSearcherOutputParser
 {
 public:
-    SilverSearcherOutputParser(const QByteArray &output);
+    SilverSearcherOutputParser(
+            const QByteArray &output,
+            const QRegularExpression &regexp = QRegularExpression());
 
     QList<Utils::FileSearchResult> parse();
 private:
@@ -48,6 +51,8 @@ private:
     bool parseText();
 
     QByteArray output;
+    QRegularExpression regexp;
+    bool hasRegexp = false;
     int outputSize = 0;
     int index = 0;
     Utils::FileSearchResult item;
diff --git a/src/plugins/texteditor/displaysettings.cpp b/src/plugins/texteditor/displaysettings.cpp
index dd88b770887..7c0eb709664 100644
--- a/src/plugins/texteditor/displaysettings.cpp
+++ b/src/plugins/texteditor/displaysettings.cpp
@@ -142,7 +142,8 @@ bool DisplaySettings::equals(const DisplaySettings &ds) const
 
 QLabel *DisplaySettings::createAnnotationSettingsLink()
 {
-    auto label = new QLabel("<i><a href>Annotation Settings</a></i>", Core::ICore::mainWindow());
+    auto label = new QLabel("<small><i><a href>Annotation Settings</a></i></small>",
+                            Core::ICore::mainWindow());
     QObject::connect(label, &QLabel::linkActivated, []() {
         Utils::ToolTip::hideImmediately();
         Core::ICore::showOptionsDialog(Constants::TEXT_EDITOR_DISPLAY_SETTINGS);
diff --git a/src/plugins/texteditor/textmark.cpp b/src/plugins/texteditor/textmark.cpp
index 425b5773e48..17c6268f85f 100644
--- a/src/plugins/texteditor/textmark.cpp
+++ b/src/plugins/texteditor/textmark.cpp
@@ -290,6 +290,7 @@ bool TextMark::addToolTipContent(QLayout *target) const
     }
 
     auto textLabel = new QLabel;
+    textLabel->setOpenExternalLinks(true);
     textLabel->setText(text);
     // Differentiate between tool tips that where explicitly set and default tool tips.
     textLabel->setEnabled(!m_toolTip.isEmpty());
diff --git a/src/plugins/vcsbase/vcsbaseeditorconfig.cpp b/src/plugins/vcsbase/vcsbaseeditorconfig.cpp
index 6fd09901bf5..f3f96e3b3fb 100644
--- a/src/plugins/vcsbase/vcsbaseeditorconfig.cpp
+++ b/src/plugins/vcsbase/vcsbaseeditorconfig.cpp
@@ -305,9 +305,7 @@ void VcsBaseEditorConfig::updateMappedSettings()
 
 void VcsBaseEditorConfig::addAction(QAction *action)
 {
-    const QList<QAction *> actions = d->m_toolBar->actions();
-    // Insert the action before line/column and split actions.
-    d->m_toolBar->insertAction(actions.at(qMax(actions.count() - 2, 0)), action);
+    d->m_toolBar->addAction(action);
 }
 
 } // namespace VcsBase
diff --git a/src/shared/proparser/qmakeevaluator.cpp b/src/shared/proparser/qmakeevaluator.cpp
index 00c87a7a23c..3ed649163d2 100644
--- a/src/shared/proparser/qmakeevaluator.cpp
+++ b/src/shared/proparser/qmakeevaluator.cpp
@@ -1049,21 +1049,8 @@ void QMakeEvaluator::loadDefaults()
     if (GetComputerName(name, &name_length))
         vars[ProKey("QMAKE_HOST.name")] << ProString(QString::fromWCharArray(name));
 
-    QSysInfo::WinVersion ver = QSysInfo::WindowsVersion;
-    vars[ProKey("QMAKE_HOST.version")] << ProString(QString::number(ver));
-    ProString verStr;
-    switch (ver) {
-    case QSysInfo::WV_Me: verStr = ProString("WinMe"); break;
-    case QSysInfo::WV_95: verStr = ProString("Win95"); break;
-    case QSysInfo::WV_98: verStr = ProString("Win98"); break;
-    case QSysInfo::WV_NT: verStr = ProString("WinNT"); break;
-    case QSysInfo::WV_2000: verStr = ProString("Win2000"); break;
-    case QSysInfo::WV_2003: verStr = ProString("Win2003"); break;
-    case QSysInfo::WV_XP: verStr = ProString("WinXP"); break;
-    case QSysInfo::WV_VISTA: verStr = ProString("WinVista"); break;
-    default: verStr = ProString("Unknown"); break;
-    }
-    vars[ProKey("QMAKE_HOST.version_string")] << verStr;
+    vars[ProKey("QMAKE_HOST.version")] << ProString(QSysInfo::kernelVersion());
+    vars[ProKey("QMAKE_HOST.version_string")] << ProString(QSysInfo::productVersion());
 
     SYSTEM_INFO info;
     GetSystemInfo(&info);
diff --git a/src/tools/icons/export.py b/src/tools/icons/export.py
index e28b7e6e4e9..6943b18fd74 100644
--- a/src/tools/icons/export.py
+++ b/src/tools/icons/export.py
@@ -77,9 +77,12 @@ for id in svgIDs:
 # The shell mode of Inkscape is used to execute several export commands
 # with one launch of Inkscape.
 inkscapeShellCommands = ""
+pngFiles = []
 for id in svgIDs:
-    inkscapeShellCommands += "qtcreatoricons.svg --export-id=" + id + " --export-id-only --export-png=" + qtcSourceRoot + id + ".png --export-dpi=96\n"
-    inkscapeShellCommands += "qtcreatoricons.svg --export-id=" + id + " --export-id-only --export-png=" + qtcSourceRoot + id + "@2x.png --export-dpi=192\n"
+    for scale in [1, 2]:
+        pngFile = qtcSourceRoot + id + ("" if scale is 1 else "@%dx" % scale) + ".png"
+        pngFiles.append(pngFile)
+        inkscapeShellCommands += "qtcreatoricons.svg --export-id=" + id + " --export-id-only --export-png=" + pngFile + " --export-dpi=%d\n" % (scale * 96)
 inkscapeShellCommands += "quit\n"
 inkscapeProcess = subprocess.Popen(['inkscape', '--shell'], stdin=subprocess.PIPE, shell=True, cwd=scriptDir)
 inkscapeProcess.communicate(input=inkscapeShellCommands.encode())
@@ -89,6 +92,5 @@ optipngExecutable = spawn.find_executable("optipng")
 if not optipngExecutable:
     sys.stderr.write("optipng was not found in PATH. Please do not push the unoptimized .pngs to the main repository.\n")
 else:
-    for id in svgIDs:
-        subprocess.call(["optipng", "-o7", "-strip", "all", qtcSourceRoot + id + ".png"])
-        subprocess.call(["optipng", "-o7", "-strip", "all", qtcSourceRoot + id + "@2x.png"])
+    for pngFile in pngFiles:
+        subprocess.call(["optipng", "-o7", "-strip", "all", pngFile])
diff --git a/tests/unit/mockup/projectexplorer/toolchain.h b/tests/unit/mockup/projectexplorer/toolchain.h
index 93cb630c4c6..985184af851 100644
--- a/tests/unit/mockup/projectexplorer/toolchain.h
+++ b/tests/unit/mockup/projectexplorer/toolchain.h
@@ -25,8 +25,9 @@
 
 #pragma once
 
-#include <projectexplorer/headerpath.h>
 #include <projectexplorer/abi.h>
+#include <projectexplorer/headerpath.h>
+#include <projectexplorer/language.h>
 #include <projectexplorer/projectmacro.h>
 #include <coreplugin/id.h>
 
@@ -39,29 +40,19 @@ class ToolChain
 public:
     Core::Id typeId() const { return Core::Id(); }
 
-    enum CompilerFlag {
-        NoFlags = 0,
-        StandardCxx11 = 0x1,
-        StandardC99 = 0x2,
-        StandardC11 = 0x4,
-        GnuExtensions = 0x8,
-        MicrosoftExtensions = 0x10,
-        BorlandExtensions = 0x20,
-        OpenMP = 0x40,
-        ObjectiveC = 0x80,
-        StandardCxx14 = 0x100,
-        StandardCxx17 = 0x200,
-        StandardCxx98 = 0x400,
-    };
-    Q_DECLARE_FLAGS(CompilerFlags, CompilerFlag)
-
     Abi targetAbi() const { return Abi(); }
 
     using BuiltInHeaderPathsRunner = std::function<HeaderPaths(const QStringList &cxxflags, const QString &sysRoot)>;
     virtual BuiltInHeaderPathsRunner createBuiltInHeaderPathsRunner() const { return BuiltInHeaderPathsRunner(); }
 
-    using PredefinedMacrosRunner = std::function<Macros(const QStringList &cxxflags)>;
-    virtual PredefinedMacrosRunner createPredefinedMacrosRunner() const { return PredefinedMacrosRunner(); }
+    class MacroInspectionReport
+    {
+    public:
+        Macros macros;
+        LanguageVersion languageVersion; // Derived from macros.
+    };
+    using MacroInspectionRunner = std::function<MacroInspectionReport(const QStringList &cxxflags)>;
+    virtual MacroInspectionRunner createMacroInspectionRunner() const = 0;
 
     virtual QString originalTargetTriple() const { return QString(); }
     virtual QStringList extraCodeModelFlags() const { return QStringList(); }
diff --git a/tests/unit/unittest/compileroptionsbuilder-test.cpp b/tests/unit/unittest/compileroptionsbuilder-test.cpp
index ae81f7d0cae..662ff7787f8 100644
--- a/tests/unit/unittest/compileroptionsbuilder-test.cpp
+++ b/tests/unit/unittest/compileroptionsbuilder-test.cpp
@@ -41,23 +41,30 @@ using ProjectExplorer::Project;
 
 MATCHER_P(IsPartOfHeader, headerPart, std::string(negation ? "isn't " : "is ") + headerPart)
 {
-    return arg.contains(QString::fromUtf8(headerPart));
+    return arg.contains(QString::fromStdString(headerPart));
 }
+namespace {
 
-class CompilerOptionsBuilderTest : public ::testing::Test
+class CompilerOptionsBuilder : public ::testing::Test
 {
 protected:
     void SetUp() final
     {
         projectPart.project = project.get();
         projectPart.toolchainType = ProjectExplorer::Constants::CLANG_TOOLCHAIN_TYPEID;
-        projectPart.languageVersion = CppTools::ProjectPart::CXX17;
+        projectPart.languageVersion = ProjectExplorer::LanguageVersion::CXX17;
         projectPart.toolChainWordWidth = CppTools::ProjectPart::WordWidth64Bit;
         projectPart.toolChainTargetTriple = "x86_64-apple-darwin10";
         projectPart.extraCodeModelFlags = QStringList{"-arch", "x86_64"};
 
         projectPart.precompiledHeaders = QStringList{TESTDATA_DIR "/compileroptionsbuilder.pch"};
-        projectPart.toolChainMacros = {ProjectExplorer::Macro{"foo", "bar"}};
+        projectPart.toolChainMacros = {ProjectExplorer::Macro{"foo", "bar"},
+                                       ProjectExplorer::Macro{"__cplusplus", "2"},
+                                       ProjectExplorer::Macro{"__STDC_VERSION__", "2"},
+                                       ProjectExplorer::Macro{"_MSVC_LANG", "2"},
+                                       ProjectExplorer::Macro{"_MSC_BUILD", "2"},
+                                       ProjectExplorer::Macro{"_MSC_FULL_VER", "1900"},
+                                       ProjectExplorer::Macro{"_MSC_VER", "19"}};
         projectPart.projectMacros = {ProjectExplorer::Macro{"projectFoo", "projectBar"}};
         projectPart.qtVersion = ProjectPart::Qt5;
 
@@ -68,31 +75,51 @@ protected:
 
     std::unique_ptr<Project> project{std::make_unique<ProjectExplorer::Project>()};
     ProjectPart projectPart;
-    CompilerOptionsBuilder compilerOptionsBuilder{projectPart};
+    CppTools::CompilerOptionsBuilder compilerOptionsBuilder{projectPart};
 };
 
-TEST_F(CompilerOptionsBuilderTest, AddToolchainAndProjectMacros)
+TEST_F(CompilerOptionsBuilder, AddToolchainAndProjectMacros)
 {
     compilerOptionsBuilder.addToolchainAndProjectMacros();
 
     ASSERT_THAT(compilerOptionsBuilder.options(), ElementsAre("-Dfoo=bar", "-DprojectFoo=projectBar"));
 }
 
-TEST_F(CompilerOptionsBuilderTest, AddWordWidth)
+TEST_F(CompilerOptionsBuilder, AddToolchainAndProjectMacrosWithoutSkipingLanguageDefines)
+{
+    CppTools::CompilerOptionsBuilder compilerOptionsBuilder{projectPart,
+                                                            CppTools::UseSystemHeader::No,
+                                                            CppTools::SkipBuiltIn::No,
+                                                            CppTools:: SkipLanguageDefines::No};
+
+    compilerOptionsBuilder.addToolchainAndProjectMacros();
+
+    ASSERT_THAT(compilerOptionsBuilder.options(),
+                ElementsAre("-Dfoo=bar",
+                            "-D__cplusplus=2",
+                            "-D__STDC_VERSION__=2",
+                            "-D_MSVC_LANG=2",
+                            "-D_MSC_BUILD=2",
+                            "-D_MSC_FULL_VER=1900",
+                            "-D_MSC_VER=19",
+                            "-DprojectFoo=projectBar"));
+}
+
+TEST_F(CompilerOptionsBuilder, AddWordWidth)
 {
     compilerOptionsBuilder.addWordWidth();
 
     ASSERT_THAT(compilerOptionsBuilder.options(), ElementsAre("-m64"));
 }
 
-TEST_F(CompilerOptionsBuilderTest, AddToolchainFlags)
+TEST_F(CompilerOptionsBuilder, AddToolchainFlags)
 {
     compilerOptionsBuilder.addToolchainFlags();
 
     ASSERT_THAT(compilerOptionsBuilder.options(), ElementsAre("-undef"));
 }
 
-TEST_F(CompilerOptionsBuilderTest, HeaderPathOptionsOrder)
+TEST_F(CompilerOptionsBuilder, HeaderPathOptionsOrder)
 {
     compilerOptionsBuilder.addHeaderPathOptions();
 
@@ -103,9 +130,9 @@ TEST_F(CompilerOptionsBuilderTest, HeaderPathOptionsOrder)
                             "-isystem", QDir::toNativeSeparators("/tmp/builtin_path")));
 }
 
-TEST_F(CompilerOptionsBuilderTest, UseSystemHeader)
+TEST_F(CompilerOptionsBuilder, UseSystemHeader)
 {
-    CompilerOptionsBuilder compilerOptionsBuilder(projectPart, CppTools::UseSystemHeader::Yes);
+    CppTools::CompilerOptionsBuilder compilerOptionsBuilder(projectPart, CppTools::UseSystemHeader::Yes);
 
     compilerOptionsBuilder.addHeaderPathOptions();
 
@@ -116,13 +143,14 @@ TEST_F(CompilerOptionsBuilderTest, UseSystemHeader)
                             "-isystem", QDir::toNativeSeparators("/tmp/builtin_path")));
 }
 
-TEST_F(CompilerOptionsBuilderTest, ClangHeadersPath)
+TEST_F(CompilerOptionsBuilder, ClangHeadersPath)
 {
-    CompilerOptionsBuilder compilerOptionsBuilder(projectPart,
-                                                  CppTools::UseSystemHeader::No,
-                                                  CppTools::SkipBuiltIn::No,
-                                                  "7.0.0",
-                                                  "");
+    CppTools::CompilerOptionsBuilder compilerOptionsBuilder(projectPart,
+                                                            CppTools::UseSystemHeader::No,
+                                                            CppTools::SkipBuiltIn::No,
+                                                            CppTools::SkipLanguageDefines::Yes,
+                                                            "7.0.0",
+                                                            "");
 
     compilerOptionsBuilder.addHeaderPathOptions();
 
@@ -135,7 +163,7 @@ TEST_F(CompilerOptionsBuilderTest, ClangHeadersPath)
                             "-isystem", QDir::toNativeSeparators("/tmp/builtin_path")));
 }
 
-TEST_F(CompilerOptionsBuilderTest, ClangHeadersAndCppIncludesPathsOrderMacOs)
+TEST_F(CompilerOptionsBuilder, ClangHeadersAndCppIncludesPathsOrderMacOs)
 {
     auto defaultPaths = projectPart.headerPaths;
     projectPart.headerPaths = {HeaderPath{"/usr/include/c++/4.2.1", HeaderPathType::BuiltIn},
@@ -146,11 +174,12 @@ TEST_F(CompilerOptionsBuilderTest, ClangHeadersAndCppIncludesPathsOrderMacOs)
                                HeaderPath{"/usr/include", HeaderPathType::BuiltIn}
                               };
     projectPart.headerPaths.append(defaultPaths);
-    CompilerOptionsBuilder compilerOptionsBuilder(projectPart,
-                                                  CppTools::UseSystemHeader::No,
-                                                  CppTools::SkipBuiltIn::No,
-                                                  "7.0.0",
-                                                  "");
+    CppTools::CompilerOptionsBuilder compilerOptionsBuilder(projectPart,
+                                                            CppTools::UseSystemHeader::No,
+                                                            CppTools::SkipBuiltIn::No,
+                                                            CppTools::SkipLanguageDefines::Yes,
+                                                            "7.0.0",
+                                                            "");
 
     compilerOptionsBuilder.addHeaderPathOptions();
 
@@ -168,7 +197,7 @@ TEST_F(CompilerOptionsBuilderTest, ClangHeadersAndCppIncludesPathsOrderMacOs)
                             "-isystem", QDir::toNativeSeparators("/tmp/builtin_path")));
 }
 
-TEST_F(CompilerOptionsBuilderTest, ClangHeadersAndCppIncludesPathsOrderLinux)
+TEST_F(CompilerOptionsBuilder, ClangHeadersAndCppIncludesPathsOrderLinux)
 {
     projectPart.headerPaths = {HeaderPath{"/usr/lib/gcc/x86_64-linux-gnu/4.8/../../../../include/c++/4.8", HeaderPathType::BuiltIn},
                                HeaderPath{"/usr/lib/gcc/x86_64-linux-gnu/4.8/../../../../include/c++/4.8/backward", HeaderPathType::BuiltIn},
@@ -179,11 +208,12 @@ TEST_F(CompilerOptionsBuilderTest, ClangHeadersAndCppIncludesPathsOrderLinux)
                                HeaderPath{"/usr/include", HeaderPathType::BuiltIn}
                               };
     projectPart.toolChainTargetTriple = "x86_64-linux-gnu";
-    CompilerOptionsBuilder compilerOptionsBuilder(projectPart,
-                                                  CppTools::UseSystemHeader::No,
-                                                  CppTools::SkipBuiltIn::No,
-                                                  "7.0.0",
-                                                  "");
+    CppTools::CompilerOptionsBuilder compilerOptionsBuilder(projectPart,
+                                                            CppTools::UseSystemHeader::No,
+                                                            CppTools::SkipBuiltIn::No,
+                                                            CppTools::SkipLanguageDefines::Yes,
+                                                            "7.0.0",
+                                                            "");
 
     compilerOptionsBuilder.addHeaderPathOptions();
 
@@ -200,75 +230,75 @@ TEST_F(CompilerOptionsBuilderTest, ClangHeadersAndCppIncludesPathsOrderLinux)
                             "-isystem", QDir::toNativeSeparators("/usr/include")));
 }
 
-TEST_F(CompilerOptionsBuilderTest, NoPrecompiledHeader)
+TEST_F(CompilerOptionsBuilder, NoPrecompiledHeader)
 {
-    compilerOptionsBuilder.addPrecompiledHeaderOptions(CompilerOptionsBuilder::PchUsage::None);
+    compilerOptionsBuilder.addPrecompiledHeaderOptions(CppTools::CompilerOptionsBuilder::PchUsage::None);
 
     ASSERT_THAT(compilerOptionsBuilder.options().empty(), true);
 }
 
-TEST_F(CompilerOptionsBuilderTest, UsePrecompiledHeader)
+TEST_F(CompilerOptionsBuilder, UsePrecompiledHeader)
 {
-    compilerOptionsBuilder.addPrecompiledHeaderOptions(CompilerOptionsBuilder::PchUsage::Use);
+    compilerOptionsBuilder.addPrecompiledHeaderOptions(CppTools::CompilerOptionsBuilder::PchUsage::Use);
 
     ASSERT_THAT(compilerOptionsBuilder.options(),
                 ElementsAre("-include", QDir::toNativeSeparators(TESTDATA_DIR "/compileroptionsbuilder.pch")));
 }
 
-TEST_F(CompilerOptionsBuilderTest, AddMacros)
+TEST_F(CompilerOptionsBuilder, AddMacros)
 {
     compilerOptionsBuilder.addMacros(ProjectExplorer::Macros{ProjectExplorer::Macro{"key", "value"}});
 
     ASSERT_THAT(compilerOptionsBuilder.options(), ElementsAre("-Dkey=value"));
 }
 
-TEST_F(CompilerOptionsBuilderTest, AddTargetTriple)
+TEST_F(CompilerOptionsBuilder, AddTargetTriple)
 {
     compilerOptionsBuilder.addTargetTriple();
 
     ASSERT_THAT(compilerOptionsBuilder.options(), ElementsAre("-target", "x86_64-apple-darwin10"));
 }
 
-TEST_F(CompilerOptionsBuilderTest, EnableCExceptions)
+TEST_F(CompilerOptionsBuilder, EnableCExceptions)
 {
-    projectPart.languageVersion = CppTools::ProjectPart::C99;
+    projectPart.languageVersion = ProjectExplorer::LanguageVersion::C99;
 
     compilerOptionsBuilder.enableExceptions();
 
     ASSERT_THAT(compilerOptionsBuilder.options(), ElementsAre("-fexceptions"));
 }
 
-TEST_F(CompilerOptionsBuilderTest, EnableCXXExceptions)
+TEST_F(CompilerOptionsBuilder, EnableCXXExceptions)
 {
     compilerOptionsBuilder.enableExceptions();
 
     ASSERT_THAT(compilerOptionsBuilder.options(), ElementsAre("-fcxx-exceptions", "-fexceptions"));
 }
 
-TEST_F(CompilerOptionsBuilderTest, InsertWrappedQtHeaders)
+TEST_F(CompilerOptionsBuilder, InsertWrappedQtHeaders)
 {
     compilerOptionsBuilder.insertWrappedQtHeaders();
 
     ASSERT_THAT(compilerOptionsBuilder.options(), Contains(IsPartOfHeader("wrappedQtHeaders")));
 }
 
-TEST_F(CompilerOptionsBuilderTest, SetLanguageVersion)
+TEST_F(CompilerOptionsBuilder, SetLanguageVersion)
 {
     compilerOptionsBuilder.updateLanguageOption(ProjectFile::CXXSource);
 
     ASSERT_THAT(compilerOptionsBuilder.options(), ElementsAre("-x", "c++"));
 }
 
-TEST_F(CompilerOptionsBuilderTest, HandleLanguageExtension)
+TEST_F(CompilerOptionsBuilder, HandleLanguageExtension)
 {
-    projectPart.languageExtensions = ProjectPart::ObjectiveCExtensions;
+    projectPart.languageExtensions = ProjectExplorer::LanguageExtension::ObjectiveC;
 
     compilerOptionsBuilder.updateLanguageOption(ProjectFile::CXXSource);
 
     ASSERT_THAT(compilerOptionsBuilder.options(), ElementsAre("-x", "objective-c++"));
 }
 
-TEST_F(CompilerOptionsBuilderTest, UpdateLanguageVersion)
+TEST_F(CompilerOptionsBuilder, UpdateLanguageVersion)
 {
     compilerOptionsBuilder.updateLanguageOption(ProjectFile::CXXSource);
 
@@ -277,7 +307,7 @@ TEST_F(CompilerOptionsBuilderTest, UpdateLanguageVersion)
     ASSERT_THAT(compilerOptionsBuilder.options(), ElementsAre("-x", "c++-header"));
 }
 
-TEST_F(CompilerOptionsBuilderTest, AddMsvcCompatibilityVersion)
+TEST_F(CompilerOptionsBuilder, AddMsvcCompatibilityVersion)
 {
     projectPart.toolchainType = ProjectExplorer::Constants::MSVC_TOOLCHAIN_TYPEID;
     projectPart.toolChainMacros.append(ProjectExplorer::Macro{"_MSC_FULL_VER", "190000000"});
@@ -287,7 +317,7 @@ TEST_F(CompilerOptionsBuilderTest, AddMsvcCompatibilityVersion)
     ASSERT_THAT(compilerOptionsBuilder.options(), ElementsAre("-fms-compatibility-version=19.00"));
 }
 
-TEST_F(CompilerOptionsBuilderTest, UndefineCppLanguageFeatureMacrosForMsvc2015)
+TEST_F(CompilerOptionsBuilder, UndefineCppLanguageFeatureMacrosForMsvc2015)
 {
     projectPart.toolchainType = ProjectExplorer::Constants::MSVC_TOOLCHAIN_TYPEID;
     projectPart.isMsvc2015Toolchain = true;
@@ -297,7 +327,7 @@ TEST_F(CompilerOptionsBuilderTest, UndefineCppLanguageFeatureMacrosForMsvc2015)
     ASSERT_THAT(compilerOptionsBuilder.options(), Contains(QString{"-U__cpp_aggregate_bases"}));
 }
 
-TEST_F(CompilerOptionsBuilderTest, AddDefineFunctionMacrosMsvc)
+TEST_F(CompilerOptionsBuilder, AddDefineFunctionMacrosMsvc)
 {
     projectPart.toolchainType = ProjectExplorer::Constants::MSVC_TOOLCHAIN_TYPEID;
 
@@ -306,7 +336,7 @@ TEST_F(CompilerOptionsBuilderTest, AddDefineFunctionMacrosMsvc)
     ASSERT_THAT(compilerOptionsBuilder.options(), Contains(QString{"-D__FUNCTION__=\"\""}));
 }
 
-TEST_F(CompilerOptionsBuilderTest, AddProjectConfigFileInclude)
+TEST_F(CompilerOptionsBuilder, AddProjectConfigFileInclude)
 {
     projectPart.projectConfigFile = "dummy_file.h";
 
@@ -315,7 +345,7 @@ TEST_F(CompilerOptionsBuilderTest, AddProjectConfigFileInclude)
     ASSERT_THAT(compilerOptionsBuilder.options(), ElementsAre("-include", "dummy_file.h"));
 }
 
-TEST_F(CompilerOptionsBuilderTest, UndefineClangVersionMacrosForMsvc)
+TEST_F(CompilerOptionsBuilder, UndefineClangVersionMacrosForMsvc)
 {
     projectPart.toolchainType = ProjectExplorer::Constants::MSVC_TOOLCHAIN_TYPEID;
 
@@ -324,20 +354,21 @@ TEST_F(CompilerOptionsBuilderTest, UndefineClangVersionMacrosForMsvc)
     ASSERT_THAT(compilerOptionsBuilder.options(), Contains(QString{"-U__clang__"}));
 }
 
-TEST_F(CompilerOptionsBuilderTest, BuildAllOptions)
+TEST_F(CompilerOptionsBuilder, BuildAllOptions)
 {
-    compilerOptionsBuilder.build(ProjectFile::CXXSource, CompilerOptionsBuilder::PchUsage::None);
+    compilerOptionsBuilder.build(ProjectFile::CXXSource, CppTools::CompilerOptionsBuilder::PchUsage::None);
 
     ASSERT_THAT(compilerOptionsBuilder.options(),
                 ElementsAre(
                     "-nostdlibinc", "-c", "-m64", "-target", "x86_64-apple-darwin10",
                     "-arch", "x86_64", "-x", "c++", "-std=c++17", "-fcxx-exceptions",
                     "-fexceptions", "-Dfoo=bar", "-DprojectFoo=projectBar", "-undef",
-                    "-I", QDir::toNativeSeparators("D:/code/qt-creator/tests/unit/unittest/../../../share/qtcreator/cplusplus/wrappedQtHeaders"),
-                    "-I", QDir::toNativeSeparators("D:/code/qt-creator/tests/unit/unittest/../../../share/qtcreator/cplusplus/wrappedQtHeaders/QtCore"),
+                    "-I", IsPartOfHeader("wrappedQtHeaders"),
+                    "-I", IsPartOfHeader(QDir::toNativeSeparators("wrappedQtHeaders/QtCore").toStdString()),
                     "-I", QDir::toNativeSeparators("/tmp/path"),
                     "-I", QDir::toNativeSeparators("/tmp/system_path"),
                     "-isystem", QDir::toNativeSeparators("/tmp/builtin_path")
                     ));
 }
 
+}
diff --git a/tests/unit/unittest/cppprojectinfogenerator-test.cpp b/tests/unit/unittest/cppprojectinfogenerator-test.cpp
index 9a991a75204..f1e24b5aee6 100644
--- a/tests/unit/unittest/cppprojectinfogenerator-test.cpp
+++ b/tests/unit/unittest/cppprojectinfogenerator-test.cpp
@@ -39,6 +39,7 @@ using CppTools::ProjectUpdateInfo;
 using CppTools::ProjectPart;
 using CppTools::RawProjectPart;
 
+using ProjectExplorer::Macros;
 using ProjectExplorer::ToolChain;
 
 using testing::Eq;
@@ -65,6 +66,7 @@ protected:
     ProjectInfo generate();
 
 protected:
+    ProjectUpdateInfo projectUpdateInfo;
     RawProjectPart rawProjectPart;
 };
 
@@ -101,7 +103,7 @@ TEST_F(ProjectInfoGenerator, ProjectPartIndicatesObjectiveCExtensionsByDefault)
 
     ASSERT_THAT(projectInfo.projectParts().size(), Eq(1));
     const ProjectPart &projectPart = *projectInfo.projectParts().at(0);
-    ASSERT_TRUE(projectPart.languageExtensions & ProjectPart::ObjectiveCExtensions);
+    ASSERT_TRUE(projectPart.languageExtensions & ProjectExplorer::LanguageExtension::ObjectiveC);
 }
 
 TEST_F(ProjectInfoGenerator, ProjectPartHasLatestLanguageVersionByDefault)
@@ -112,31 +114,33 @@ TEST_F(ProjectInfoGenerator, ProjectPartHasLatestLanguageVersionByDefault)
 
     ASSERT_THAT(projectInfo.projectParts().size(), Eq(1));
     const ProjectPart &projectPart = *projectInfo.projectParts().at(0);
-    ASSERT_THAT(projectPart.languageVersion, Eq(ProjectPart::LatestCxxVersion));
+    ASSERT_THAT(projectPart.languageVersion, Eq(ProjectExplorer::LanguageVersion::LatestCxx));
 }
 
-TEST_F(ProjectInfoGenerator, UseCompilerFlagsForLanguageVersion)
+TEST_F(ProjectInfoGenerator, UseMacroInspectionReportForLanguageVersion)
 {
+    projectUpdateInfo.cxxToolChainInfo.macroInspectionRunner = [](const QStringList &) {
+        return ToolChain::MacroInspectionReport{Macros(), ProjectExplorer::LanguageVersion::CXX17};
+    };
     rawProjectPart.files = QStringList{ "foo.cpp" };
-    rawProjectPart.flagsForCxx.compilerFlags = ToolChain::CompilerFlag::StandardCxx98;
 
     const ProjectInfo projectInfo = generate();
 
     ASSERT_THAT(projectInfo.projectParts().size(), Eq(1));
     const ProjectPart &projectPart = *projectInfo.projectParts().at(0);
-    ASSERT_THAT(projectPart.languageVersion, Eq(ProjectPart::CXX98));
+    ASSERT_THAT(projectPart.languageVersion, Eq(ProjectExplorer::LanguageVersion::CXX17));
 }
 
-TEST_F(ProjectInfoGenerator, UseCompilerFlagsForLangaugeExtensions)
+TEST_F(ProjectInfoGenerator, UseCompilerFlagsForLanguageExtensions)
 {
     rawProjectPart.files = QStringList{ "foo.cpp" };
-    rawProjectPart.flagsForCxx.compilerFlags = ToolChain::CompilerFlag::MicrosoftExtensions;
+    rawProjectPart.flagsForCxx.languageExtensions = ProjectExplorer::LanguageExtension::Microsoft;
 
     const ProjectInfo projectInfo = generate();
 
     ASSERT_THAT(projectInfo.projectParts().size(), Eq(1));
     const ProjectPart &projectPart = *projectInfo.projectParts().at(0);
-    ASSERT_TRUE(projectPart.languageExtensions & ProjectPart::MicrosoftExtensions);
+    ASSERT_TRUE(projectPart.languageExtensions & ProjectExplorer::LanguageExtension::Microsoft);
 }
 
 TEST_F(ProjectInfoGenerator, ProjectFileKindsMatchProjectPartVersion)
@@ -146,10 +150,10 @@ TEST_F(ProjectInfoGenerator, ProjectFileKindsMatchProjectPartVersion)
     const ProjectInfo projectInfo = generate();
 
     ASSERT_THAT(projectInfo.projectParts(),
-                UnorderedElementsAre(IsProjectPart(ProjectPart::LatestCVersion, ProjectFile::CHeader),
-                                     IsProjectPart(ProjectPart::LatestCVersion, ProjectFile::ObjCHeader),
-                                     IsProjectPart(ProjectPart::LatestCxxVersion, ProjectFile::CXXHeader),
-                                     IsProjectPart(ProjectPart::LatestCxxVersion, ProjectFile::ObjCXXHeader)));
+                UnorderedElementsAre(IsProjectPart(ProjectExplorer::LanguageVersion::LatestC, ProjectFile::CHeader),
+                                     IsProjectPart(ProjectExplorer::LanguageVersion::LatestC, ProjectFile::ObjCHeader),
+                                     IsProjectPart(ProjectExplorer::LanguageVersion::LatestCxx, ProjectFile::CXXHeader),
+                                     IsProjectPart(ProjectExplorer::LanguageVersion::LatestCxx, ProjectFile::ObjCXXHeader)));
 }
 
 void ProjectInfoGenerator::SetUp()
@@ -160,7 +164,7 @@ void ProjectInfoGenerator::SetUp()
 ProjectInfo ProjectInfoGenerator::generate()
 {
     QFutureInterface<void> fi;
-    ProjectUpdateInfo projectUpdateInfo;
+
     projectUpdateInfo.rawProjectParts += rawProjectPart;
     ::ProjectInfoGenerator generator(fi, projectUpdateInfo);
 
diff --git a/tests/unit/unittest/cppprojectpartchooser-test.cpp b/tests/unit/unittest/cppprojectpartchooser-test.cpp
index 8020d1a35cc..299a888fb76 100644
--- a/tests/unit/unittest/cppprojectpartchooser-test.cpp
+++ b/tests/unit/unittest/cppprojectpartchooser-test.cpp
@@ -342,12 +342,12 @@ QList<ProjectPart::Ptr> ProjectPartChooser::createCAndCxxProjectParts()
 
     // Create project part for C
     const ProjectPart::Ptr cprojectpart{new ProjectPart};
-    cprojectpart->languageVersion = ProjectPart::C11;
+    cprojectpart->languageVersion = ProjectExplorer::LanguageVersion::C11;
     projectParts.append(cprojectpart);
 
     // Create project part for CXX
     const ProjectPart::Ptr cxxprojectpart{new ProjectPart};
-    cxxprojectpart->languageVersion = ProjectPart::CXX98;
+    cxxprojectpart->languageVersion = ProjectExplorer::LanguageVersion::CXX98;
     projectParts.append(cxxprojectpart);
 
     return projectParts;