diff --git a/kdevplatform/project/interfaces/ibuildsystemmanager.h b/kdevplatform/project/interfaces/ibuildsystemmanager.h
--- a/kdevplatform/project/interfaces/ibuildsystemmanager.h
+++ b/kdevplatform/project/interfaces/ibuildsystemmanager.h
@@ -130,6 +130,11 @@
      * @returns the extra arguments that will be passed to the compiler when building @p item
      */
     virtual QString extraArguments(ProjectBaseItem* item) const = 0;
+
+    /**
+     * @returns the absolute path to the tool that will be used or an empty path if unknown
+     */
+    virtual Path compiler(KDevelop::ProjectTargetItem* p) const = 0;
 };
 
 }
diff --git a/plugins/cmake/cmakemanager.h b/plugins/cmake/cmakemanager.h
--- a/plugins/cmake/cmakemanager.h
+++ b/plugins/cmake/cmakemanager.h
@@ -137,6 +137,8 @@
 
     void integrateData(const CMakeProjectData &data, KDevelop::IProject* project);
 
+    KDevelop::Path compiler(KDevelop::ProjectTargetItem * p) const override;
+
 Q_SIGNALS:
     void folderRenamed(const KDevelop::Path& oldFolder, KDevelop::ProjectFolderItem* newFolder);
     void fileRenamed(const KDevelop::Path& oldFile, KDevelop::ProjectFileItem* newFile);
@@ -154,6 +156,7 @@
 private:
     void reloadProjects();
     CMakeFile fileInformation(KDevelop::ProjectBaseItem* item) const;
+    CMakeTarget targetInformation(KDevelop::ProjectTargetItem* item) const;
 
     void folderAdded(KDevelop::ProjectFolderItem* folder);
 
diff --git a/plugins/cmake/cmakemanager.cpp b/plugins/cmake/cmakemanager.cpp
--- a/plugins/cmake/cmakemanager.cpp
+++ b/plugins/cmake/cmakemanager.cpp
@@ -315,6 +315,8 @@
         connect(job, &KJob::finished, this, [project](KJob* job) {
             if (job->error())
                 return;
+
+            KDevelop::ICore::self()->projectController()->projectConfigurationChanged(project);
             KDevelop::ICore::self()->projectController()->reparseProject(project, true);
         });
     }
@@ -984,4 +986,35 @@
     }
 }
 
+CMakeTarget CMakeManager::targetInformation(KDevelop::ProjectTargetItem* item) const
+{
+    const auto targets = m_projects[item->project()].targets[item->parent()->path()];
+    for (auto target: targets) {
+        if (item->text() == target.name) {
+            return target;
+        }
+    }
+    return {};
+}
+
+KDevelop::Path CMakeManager::compiler(KDevelop::ProjectTargetItem* item) const
+{
+    const auto targetInfo = targetInformation(item);
+    if (targetInfo.sources.isEmpty()) {
+        qCDebug(CMAKE) << "could not find target" << item->text();
+        return {};
+    }
+
+    const auto info = m_projects[item->project()].compilationData.files[targetInfo.sources.constFirst()];
+    const auto lang = info.language;
+    if (lang.isEmpty()) {
+        qCDebug(CMAKE) << "no language for" << item << item->text() << info.defines << targetInfo.sources.constFirst();
+        return {};
+    }
+    const QString var = QLatin1String("CMAKE_") + lang + QLatin1String("_COMPILER");
+    const auto ret = CMake::readCacheValues(KDevelop::Path(buildDirectory(item), QStringLiteral("CMakeCache.txt")), {var});
+    qCDebug(CMAKE) << "compiler for" << lang << var << ret;
+    return KDevelop::Path(ret.value(var));
+}
+
 #include "cmakemanager.moc"
diff --git a/plugins/cmake/cmakeprojectdata.h b/plugins/cmake/cmakeprojectdata.h
--- a/plugins/cmake/cmakeprojectdata.h
+++ b/plugins/cmake/cmakeprojectdata.h
@@ -40,11 +40,12 @@
     KDevelop::Path::List includes;
     KDevelop::Path::List frameworkDirectories;
     QString compileFlags;
+    QString language;
     QHash<QString, QString> defines;
 };
 inline QDebug &operator<<(QDebug debug, const CMakeFile& file)
 {
-    debug << "CMakeFile(-I" << file.includes << ", -F" << file.frameworkDirectories << ", -D" << file.defines << ")";
+    debug << "CMakeFile(-I" << file.includes << ", -F" << file.frameworkDirectories << ", -D" << file.defines << ", " << file.language << ")";
     return debug.maybeSpace();
 }
 
diff --git a/plugins/cmake/cmakeserverimportjob.cpp b/plugins/cmake/cmakeserverimportjob.cpp
--- a/plugins/cmake/cmakeserverimportjob.cpp
+++ b/plugins/cmake/cmakeserverimportjob.cpp
@@ -115,6 +115,7 @@
                     CMakeFile file;
                     file.includes = kTransform<KDevelop::Path::List>(fileGroup.value(QStringLiteral("includePath")).toArray(), [](const QJsonValue& val) { return KDevelop::Path(val.toObject().value(QStringLiteral("path")).toString()); });
 
+                    file.language = fileGroup.value(QStringLiteral("language")).toString(),
                     file.compileFlags = fileGroup.value(QStringLiteral("compileFlags")).toString();
                     file.defines = processDefines(file.compileFlags, fileGroup.value(QStringLiteral("defines")).toArray());
 
diff --git a/plugins/custom-buildsystem/custombuildsystemplugin.h b/plugins/custom-buildsystem/custombuildsystemplugin.h
--- a/plugins/custom-buildsystem/custombuildsystemplugin.h
+++ b/plugins/custom-buildsystem/custombuildsystemplugin.h
@@ -52,6 +52,9 @@
     /// @p installPrefix will be passed as DESTDIR environment variable
     KJob* install( KDevelop::ProjectBaseItem* item, const QUrl &installPrefix ) override;
     KJob* configure( KDevelop::IProject* ) override;
+
+    KDevelop::Path compiler(KDevelop::ProjectTargetItem * p) const override;
+
 Q_SIGNALS:
     void built( KDevelop::ProjectBaseItem *dom );
     void installed( KDevelop::ProjectBaseItem* );
diff --git a/plugins/custom-buildsystem/custombuildsystemplugin.cpp b/plugins/custom-buildsystem/custombuildsystemplugin.cpp
--- a/plugins/custom-buildsystem/custombuildsystemplugin.cpp
+++ b/plugins/custom-buildsystem/custombuildsystemplugin.cpp
@@ -195,4 +195,9 @@
     return nullptr;
 }
 
+KDevelop::Path CustomBuildSystem::compiler(KDevelop::ProjectTargetItem* item) const
+{
+    return {};
+}
+
 #include "custombuildsystemplugin.moc"
diff --git a/plugins/custom-definesandincludes/compilerprovider/compilerfactories.h b/plugins/custom-definesandincludes/compilerprovider/compilerfactories.h
--- a/plugins/custom-definesandincludes/compilerprovider/compilerfactories.h
+++ b/plugins/custom-definesandincludes/compilerprovider/compilerfactories.h
@@ -32,6 +32,7 @@
     CompilerPointer createCompiler( const QString& name, const QString& path, bool editable = true ) const override;
 
     QString name() const override;
+    bool isSupported(const KDevelop::Path& path) const override;
 
     void registerDefaultCompilers(CompilerProvider* provider) const override;
 };
@@ -42,6 +43,7 @@
     CompilerPointer createCompiler( const QString& name, const QString& path, bool editable = true ) const override;
 
     QString name() const override;
+    bool isSupported(const KDevelop::Path& path) const override;
 
     void registerDefaultCompilers(CompilerProvider* provider) const override;
 };
@@ -52,6 +54,7 @@
     CompilerPointer createCompiler( const QString& name, const QString& path, bool editable = true ) const override;
 
     QString name() const override;
+    bool isSupported(const KDevelop::Path& path) const override;
 
     void registerDefaultCompilers(CompilerProvider* provider) const override;
 };
diff --git a/plugins/custom-definesandincludes/compilerprovider/compilerfactories.cpp b/plugins/custom-definesandincludes/compilerprovider/compilerfactories.cpp
--- a/plugins/custom-definesandincludes/compilerprovider/compilerfactories.cpp
+++ b/plugins/custom-definesandincludes/compilerprovider/compilerfactories.cpp
@@ -32,6 +32,12 @@
     return QStringLiteral("Clang");
 }
 
+bool ClangFactory::isSupported(const KDevelop::Path& path) const
+{
+    const auto filename = path.lastPathSegment();
+    return filename.contains(QLatin1String("clang")) && !filename.contains(QLatin1String("clang-cl"));
+}
+
 CompilerPointer ClangFactory::createCompiler(const QString& name, const QString& path, bool editable ) const
 {
     return CompilerPointer(new GccLikeCompiler(name, path, editable, this->name()));
@@ -50,6 +56,11 @@
     return QStringLiteral("GCC");
 }
 
+bool GccFactory::isSupported(const KDevelop::Path& path) const
+{
+    return path.lastPathSegment().contains(QLatin1String("gcc")) || path.lastPathSegment().contains(QLatin1String("g++"));
+}
+
 CompilerPointer GccFactory::createCompiler(const QString& name, const QString& path, bool editable ) const
 {
     return CompilerPointer(new GccLikeCompiler(name, path, editable, this->name()));
@@ -77,3 +88,8 @@
 {
     provider->registerCompiler(createCompiler(name(), QStringLiteral("cl.exe"), false));
 }
+
+bool MsvcFactory::isSupported(const KDevelop::Path& path) const
+{
+    return path.lastPathSegment() == QLatin1String("cl.exe") || path.lastPathSegment().contains(QLatin1String("clang-cl"));
+}
diff --git a/plugins/custom-definesandincludes/compilerprovider/compilerprovider.h b/plugins/custom-definesandincludes/compilerprovider/compilerprovider.h
--- a/plugins/custom-definesandincludes/compilerprovider/compilerprovider.h
+++ b/plugins/custom-definesandincludes/compilerprovider/compilerprovider.h
@@ -67,6 +67,7 @@
 
 private Q_SLOTS:
     void retrieveUserDefinedCompilers();
+    void projectChanged(KDevelop::IProject* p);
 
 private:
     mutable CompilerPointer m_defaultProvider;
diff --git a/plugins/custom-definesandincludes/compilerprovider/compilerprovider.cpp b/plugins/custom-definesandincludes/compilerprovider/compilerprovider.cpp
--- a/plugins/custom-definesandincludes/compilerprovider/compilerprovider.cpp
+++ b/plugins/custom-definesandincludes/compilerprovider/compilerprovider.cpp
@@ -31,6 +31,8 @@
 #include <interfaces/iruntime.h>
 #include <interfaces/iruntimecontroller.h>
 #include <interfaces/iproject.h>
+#include <interfaces/iprojectcontroller.h>
+#include <interfaces/ibuildsystemmanager.h>
 #include <project/projectmodel.h>
 
 #include <KLocalizedString>
@@ -101,6 +103,22 @@
 }
 }
 
+ProjectTargetItem* findCompiledTarget(ProjectBaseItem* item)
+{
+    for(auto item: item->targetList()) {
+        if (item->type() == ProjectBaseItem::ExecutableTarget || item->type() == ProjectBaseItem::LibraryTarget) {
+            return item;
+        }
+    }
+
+    for(auto folder: item->folderList()) {
+        auto target = findCompiledTarget(folder);
+        if (target)
+            return target;
+    }
+    return nullptr;
+}
+
 CompilerProvider::CompilerProvider( SettingsManager* settings, QObject* parent )
     : QObject( parent )
     , m_settings(settings)
@@ -127,10 +145,44 @@
     retrieveUserDefinedCompilers();
 
     connect(ICore::self()->runtimeController(), &IRuntimeController::currentRuntimeChanged, this, [this]() { m_defaultProvider.clear(); });
+    connect(ICore::self()->projectController(), &IProjectController::projectConfigurationChanged, this, &CompilerProvider::projectChanged);
+    connect(ICore::self()->projectController(), &IProjectController::projectOpened, this, &CompilerProvider::projectChanged);
 }
 
 CompilerProvider::~CompilerProvider() = default;
 
+void CompilerProvider::projectChanged(KDevelop::IProject* p)
+{
+    const auto target = findCompiledTarget(p->projectItem());
+    if (!target)
+        return;
+
+    auto path = p->buildSystemManager()->compiler(target);
+    qCDebug(DEFINESANDINCLUDES) << "found compiler" << path;
+    if (path.isEmpty())
+        return;
+
+    Q_ASSERT(QDir::isAbsolutePath(path.toLocalFile()));
+    const auto pathString = path.toLocalFile();
+    auto it = std::find_if(m_compilers.begin(), m_compilers.end(),
+        [pathString](const CompilerPointer& compiler) { return compiler->path() == pathString; });
+    if (it != m_compilers.end()) {
+        m_defaultProvider = *it;
+        return;
+    }
+
+    //we need to search, sdk compiler names are weird: arm-linux-androideabi-g++
+    for (auto factory : m_factories) {
+        if (factory->isSupported(path)) {
+            auto compiler = factory->createCompiler(path.lastPathSegment(), pathString);
+            const auto registered = registerCompiler(compiler);
+            m_defaultProvider = compiler;
+        }
+    }
+
+    qCDebug(DEFINESANDINCLUDES) << "using compiler" << m_defaultProvider << path;
+}
+
 QHash<QString, QString> CompilerProvider::defines( const QString& path ) const
 {
     auto config = configForItem(nullptr);
diff --git a/plugins/custom-definesandincludes/compilerprovider/icompilerfactory.h b/plugins/custom-definesandincludes/compilerprovider/icompilerfactory.h
--- a/plugins/custom-definesandincludes/compilerprovider/icompilerfactory.h
+++ b/plugins/custom-definesandincludes/compilerprovider/icompilerfactory.h
@@ -44,6 +44,9 @@
      */
     virtual void registerDefaultCompilers(CompilerProvider* provider) const = 0;
 
+    /** @returns whether @p path is a compiler supported by the factory */
+    virtual bool isSupported(const KDevelop::Path &path) const = 0;
+
     virtual ~ICompilerFactory() = default;
 };
 
diff --git a/plugins/custommake/custommakemanager.h b/plugins/custommake/custommakemanager.h
--- a/plugins/custommake/custommakemanager.h
+++ b/plugins/custommake/custommakemanager.h
@@ -113,6 +113,8 @@
      */
     QList<KDevelop::ProjectTargetItem*> targets(KDevelop::ProjectFolderItem*) const override;
 
+    KDevelop::Path compiler(KDevelop::ProjectTargetItem * p) const override;
+
 protected:
     KDevelop::ProjectFileItem* createFileItem(KDevelop::IProject* project,
                                                       const KDevelop::Path& path,
diff --git a/plugins/custommake/custommakemanager.cpp b/plugins/custommake/custommakemanager.cpp
--- a/plugins/custommake/custommakemanager.cpp
+++ b/plugins/custommake/custommakemanager.cpp
@@ -324,5 +324,9 @@
   IDefinesAndIncludesManager::manager()->unregisterBackgroundProvider(m_provider.data());
 }
 
-#include "custommakemanager.moc"
+KDevelop::Path CustomMakeManager::compiler(KDevelop::ProjectTargetItem* item) const
+{
+    return {};
+}
 
+#include "custommakemanager.moc"
diff --git a/plugins/qmakemanager/qmakemanager.h b/plugins/qmakemanager/qmakemanager.h
--- a/plugins/qmakemanager/qmakemanager.h
+++ b/plugins/qmakemanager/qmakemanager.h
@@ -82,6 +82,8 @@
     }
 
     QList<KDevelop::ProjectTargetItem*> targets(KDevelop::ProjectFolderItem*) const override;
+
+    KDevelop::Path compiler(KDevelop::ProjectTargetItem* item) const override;
     //END IBuildSystemManager
 
 private Q_SLOTS:
diff --git a/plugins/qmakemanager/qmakemanager.cpp b/plugins/qmakemanager/qmakemanager.cpp
--- a/plugins/qmakemanager/qmakemanager.cpp
+++ b/plugins/qmakemanager/qmakemanager.cpp
@@ -514,4 +514,9 @@
     KDevelop::ICore::self()->runController()->registerJob(job);
 }
 
+KDevelop::Path QMakeProjectManager::compiler(KDevelop::ProjectTargetItem* p) const
+{
+    return {};
+}
+
 #include "qmakemanager.moc"