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 findCompiler(KDevelop::ProjectTargetItem* p) const { Q_UNUSED(p); return {}; };
 };
 
 }
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 findCompiler(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
@@ -984,4 +984,35 @@
     }
 }
 
+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::findCompiler(KDevelop::ProjectTargetItem* item) const
+{
+    const auto targetInfo = targetInformation(item);
+    if (targetInfo.sources.isEmpty()) {
+        qDebug() << "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()) {
+        qDebug() << "no lang for..." << item << item->text() << info.defines << targetInfo.sources.constFirst();
+        return {};
+    }
+    const QString var = QStringLiteral("CMAKE_") + lang + QStringLiteral("_COMPILER");
+    const auto ret = CMake::readCacheValues(KDevelop::Path(buildDirectory(item), QStringLiteral("CMakeCache.txt")), {var});
+    qDebug() << "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-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
@@ -36,6 +36,8 @@
 #include <KLocalizedString>
 #include <QStandardPaths>
 #include <QDir>
+#include <iprojectcontroller.h>
+#include <interfaces/ibuildsystemmanager.h>
 
 using namespace KDevelop;
 
@@ -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)
@@ -126,7 +144,38 @@
     registerCompiler(createDummyCompiler());
     retrieveUserDefinedCompilers();
 
-    connect(ICore::self()->runtimeController(), &IRuntimeController::currentRuntimeChanged, this, [this]() { m_defaultProvider.clear(); });
+    connect(ICore::self()->runtimeController(), &IRuntimeController::currentRuntimeChanged, this, [this]() {
+        m_defaultProvider.clear();
+
+        for (auto p : ICore::self()->projectController()->projects()) {
+            const auto target = findCompiledTarget(p->projectItem());
+            if (!target)
+                continue;
+
+            auto path = p->buildSystemManager()->findCompiler(target);
+            qCDebug(DEFINESANDINCLUDES) << "found compiler" << path;
+            if (!path.isEmpty() || !QDir::isAbsolutePath(path.toLocalFile()))
+                continue;
+
+            const auto pathString = path.toLocalFile();
+            bool alreadyPresent = false;
+            for ( const CompilerPointer& compiler : m_compilers ) {
+                if (compiler->path() == pathString) {
+                    alreadyPresent = true;
+                    break;
+                }
+            }
+            if (alreadyPresent)
+                continue;
+            //we need to search, sdk compiler names are weird: arm-linux-androideabi-g++
+            int factory = path.lastPathSegment().contains(QLatin1String("clang")) ? 1 : 0;
+            auto compiler = m_factories[factory]->createCompiler(path.lastPathSegment(), pathString);
+            registerCompiler(compiler);
+
+            qCDebug(DEFINESANDINCLUDES) << "using compiler" << compiler;
+            m_defaultProvider = compiler;
+        }
+    }, Qt::QueuedConnection);
 }
 
 CompilerProvider::~CompilerProvider() = default;