diff --git a/Makefile b/Makefile
index 0a06529ba46..d0607cde71b 100644
--- a/Makefile
+++ b/Makefile
@@ -156,7 +156,8 @@ MAN_SOURCE=man/cppcheck.1.xml
 
 ###### Object Files
 
-LIBOBJ =      $(libcppdir)/analyzerinfo.o \
+LIBOBJ =      $(libcppdir)/addonutils.o \
+              $(libcppdir)/analyzerinfo.o \
               $(libcppdir)/astutils.o \
               $(libcppdir)/check.o \
               $(libcppdir)/check64bit.o \
@@ -218,6 +219,7 @@ CLIOBJ =      cli/cmdlineparser.o \
 
 TESTOBJ =     test/options.o \
               test/test64bit.o \
+              test/testaddonutils.o \
               test/testassert.o \
               test/testastutils.o \
               test/testautovariables.o \
@@ -393,6 +395,9 @@ validateRules:
 
 ###### Build
 
+$(libcppdir)/addonutils.o: lib/addonutils.cpp externals/picojson.h lib/addonutils.h lib/config.h lib/errorlogger.h lib/path.h lib/suppressions.h lib/utils.h
+	$(CXX) ${INCLUDE_FOR_LIB} $(CPPFLAGS) $(CPPFILESDIR) $(CXXFLAGS) $(UNDEF_STRICT_ANSI) -c -o $(libcppdir)/addonutils.o $(libcppdir)/addonutils.cpp
+
 $(libcppdir)/analyzerinfo.o: lib/analyzerinfo.cpp externals/tinyxml/tinyxml2.h lib/analyzerinfo.h lib/config.h lib/errorlogger.h lib/importproject.h lib/path.h lib/platform.h lib/suppressions.h lib/utils.h
 	$(CXX) ${INCLUDE_FOR_LIB} $(CPPFLAGS) $(CPPFILESDIR) $(CXXFLAGS) $(UNDEF_STRICT_ANSI) -c -o $(libcppdir)/analyzerinfo.o $(libcppdir)/analyzerinfo.cpp
 
@@ -477,7 +482,7 @@ $(libcppdir)/checkunusedvar.o: lib/checkunusedvar.cpp lib/astutils.h lib/check.h
 $(libcppdir)/checkvaarg.o: lib/checkvaarg.cpp lib/astutils.h lib/check.h lib/checkvaarg.h lib/config.h lib/errorlogger.h lib/importproject.h lib/library.h lib/mathlib.h lib/platform.h lib/settings.h lib/standards.h lib/suppressions.h lib/symboldatabase.h lib/templatesimplifier.h lib/timer.h lib/token.h lib/tokenize.h lib/tokenlist.h lib/utils.h lib/valueflow.h
 	$(CXX) ${INCLUDE_FOR_LIB} $(CPPFLAGS) $(CPPFILESDIR) $(CXXFLAGS) $(UNDEF_STRICT_ANSI) -c -o $(libcppdir)/checkvaarg.o $(libcppdir)/checkvaarg.cpp
 
-$(libcppdir)/cppcheck.o: lib/cppcheck.cpp externals/picojson.h externals/simplecpp/simplecpp.h externals/tinyxml/tinyxml2.h lib/analyzerinfo.h lib/check.h lib/checkunusedfunctions.h lib/config.h lib/cppcheck.h lib/ctu.h lib/errorlogger.h lib/exprengine.h lib/importproject.h lib/library.h lib/mathlib.h lib/path.h lib/platform.h lib/preprocessor.h lib/settings.h lib/standards.h lib/suppressions.h lib/templatesimplifier.h lib/timer.h lib/token.h lib/tokenize.h lib/tokenlist.h lib/utils.h lib/valueflow.h lib/version.h
+$(libcppdir)/cppcheck.o: lib/cppcheck.cpp externals/simplecpp/simplecpp.h externals/tinyxml/tinyxml2.h lib/addonutils.h lib/analyzerinfo.h lib/check.h lib/checkunusedfunctions.h lib/config.h lib/cppcheck.h lib/ctu.h lib/errorlogger.h lib/exprengine.h lib/importproject.h lib/library.h lib/mathlib.h lib/path.h lib/platform.h lib/preprocessor.h lib/settings.h lib/standards.h lib/suppressions.h lib/templatesimplifier.h lib/timer.h lib/token.h lib/tokenize.h lib/tokenlist.h lib/utils.h lib/valueflow.h lib/version.h
 	$(CXX) ${INCLUDE_FOR_LIB} $(CPPFLAGS) $(CPPFILESDIR) $(CXXFLAGS) $(UNDEF_STRICT_ANSI) -c -o $(libcppdir)/cppcheck.o $(libcppdir)/cppcheck.cpp
 
 $(libcppdir)/ctu.o: lib/ctu.cpp externals/tinyxml/tinyxml2.h lib/astutils.h lib/check.h lib/config.h lib/ctu.h lib/errorlogger.h lib/importproject.h lib/library.h lib/mathlib.h lib/platform.h lib/settings.h lib/standards.h lib/suppressions.h lib/symboldatabase.h lib/templatesimplifier.h lib/timer.h lib/token.h lib/tokenize.h lib/tokenlist.h lib/utils.h lib/valueflow.h
@@ -564,6 +569,9 @@ test/options.o: test/options.cpp test/options.h
 test/test64bit.o: test/test64bit.cpp lib/check.h lib/check64bit.h lib/config.h lib/errorlogger.h lib/importproject.h lib/library.h lib/mathlib.h lib/platform.h lib/settings.h lib/standards.h lib/suppressions.h lib/templatesimplifier.h lib/timer.h lib/token.h lib/tokenize.h lib/tokenlist.h lib/utils.h lib/valueflow.h test/testsuite.h
 	$(CXX) ${INCLUDE_FOR_TEST} $(CPPFLAGS) $(CPPFILESDIR) $(CXXFLAGS) $(UNDEF_STRICT_ANSI) -c -o test/test64bit.o test/test64bit.cpp
 
+test/testaddonutils.o: test/testaddonutils.cpp lib/addonutils.h lib/config.h lib/errorlogger.h lib/importproject.h lib/library.h lib/mathlib.h lib/path.h lib/platform.h lib/settings.h lib/standards.h lib/suppressions.h lib/timer.h lib/utils.h test/testsuite.h
+	$(CXX) ${INCLUDE_FOR_TEST} $(CPPFLAGS) $(CPPFILESDIR) $(CXXFLAGS) $(UNDEF_STRICT_ANSI) -c -o test/testaddonutils.o test/testaddonutils.cpp
+
 test/testassert.o: test/testassert.cpp lib/check.h lib/checkassert.h lib/config.h lib/errorlogger.h lib/importproject.h lib/library.h lib/mathlib.h lib/platform.h lib/settings.h lib/standards.h lib/suppressions.h lib/templatesimplifier.h lib/timer.h lib/token.h lib/tokenize.h lib/tokenlist.h lib/utils.h lib/valueflow.h test/testsuite.h
 	$(CXX) ${INCLUDE_FOR_TEST} $(CPPFLAGS) $(CPPFILESDIR) $(CXXFLAGS) $(UNDEF_STRICT_ANSI) -c -o test/testassert.o test/testassert.cpp
 
diff --git a/gui/checkthread.cpp b/gui/checkthread.cpp
index 31703812aa9..216e6e5d5ef 100644
--- a/gui/checkthread.cpp
+++ b/gui/checkthread.cpp
@@ -25,6 +25,8 @@
 #include <QJsonObject>
 #include <QProcess>
 #include <QSettings>
+
+#include "addonutils.h"
 #include "checkthread.h"
 #include "erroritem.h"
 #include "threadresult.h"
@@ -112,9 +114,13 @@ void CheckThread::run()
 void CheckThread::runAddonsAndTools(const ImportProject::FileSettings *fileSettings, const QString &fileName)
 {
     QString dumpFile;
+    auto disabled_addons = QStringList();
+
+    foreach (const QString addon_name, mAddonsAndTools) {
+        if (disabled_addons.contains(addon_name))
+            continue;
 
-    foreach (const QString addon, mAddonsAndTools) {
-        if (addon == CLANG_ANALYZER || addon == CLANG_TIDY) {
+        if (addon_name == CLANG_ANALYZER || addon_name == CLANG_TIDY) {
             if (!fileSettings)
                 continue;
 
@@ -196,15 +202,15 @@ void CheckThread::runAddonsAndTools(const ImportProject::FileSettings *fileSetti
                 const QByteArray &ba = process.readAllStandardOutput();
                 const quint16 chksum = qChecksum(ba.data(), ba.length());
 
-                QFile f1(analyzerInfoFile + '.' + addon + "-E");
+                QFile f1(analyzerInfoFile + '.' + addon_name + "-E");
                 if (f1.open(QIODevice::ReadOnly | QIODevice::Text)) {
                     QTextStream in1(&f1);
                     const quint16 oldchksum = in1.readAll().toInt();
                     if (oldchksum == chksum) {
-                        QFile f2(analyzerInfoFile + '.' + addon + "-results");
+                        QFile f2(analyzerInfoFile + '.' + addon_name + "-results");
                         if (f2.open(QIODevice::ReadOnly | QIODevice::Text)) {
                             QTextStream in2(&f2);
-                            parseClangErrors(addon, fileName, in2.readAll());
+                            parseClangErrors(addon_name, fileName, in2.readAll());
                             continue;
                         }
                     }
@@ -214,10 +220,10 @@ void CheckThread::runAddonsAndTools(const ImportProject::FileSettings *fileSetti
                 QTextStream out1(&f1);
                 out1 << chksum;
 
-                QFile::remove(analyzerInfoFile + '.' + addon + "-results");
+                QFile::remove(analyzerInfoFile + '.' + addon_name + "-results");
             }
 
-            if (addon == CLANG_ANALYZER) {
+            if (addon_name == CLANG_ANALYZER) {
                 /*
                 // Using clang
                 args.insert(0,"--analyze");
@@ -247,7 +253,7 @@ void CheckThread::runAddonsAndTools(const ImportProject::FileSettings *fileSetti
                 qDebug() << debug;
 
                 if (!analyzerInfoFile.isEmpty()) {
-                    QFile f(analyzerInfoFile + '.' + addon + "-cmd");
+                    QFile f(analyzerInfoFile + '.' + addon_name + "-cmd");
                     if (f.open(QIODevice::WriteOnly | QIODevice::Text)) {
                         QTextStream out(&f);
                         out << debug;
@@ -260,22 +266,32 @@ void CheckThread::runAddonsAndTools(const ImportProject::FileSettings *fileSetti
             process.waitForFinished(600*1000);
             const QString errout(process.readAllStandardOutput() + "\n\n\n" + process.readAllStandardError());
             if (!analyzerInfoFile.isEmpty()) {
-                QFile f(analyzerInfoFile + '.' + addon + "-results");
+                QFile f(analyzerInfoFile + '.' + addon_name + "-results");
                 if (f.open(QIODevice::WriteOnly | QIODevice::Text)) {
                     QTextStream out(&f);
                     out << errout;
                 }
             }
 
-            parseClangErrors(addon, fileName, errout);
+            parseClangErrors(addon_name, fileName, errout);
         } else {
             const QString python = CheckThread::pythonCmd();
-            if (python.isEmpty())
+            if (python.isEmpty()) {
+                emit showCheckError("python-error",
+                                    tr("Addon error").arg(addon_name),
+                                    tr("Python is not available.\nAddons will be disabled for current check.").arg(addon_name));
+                disabled_addons.append(addon_name);
                 continue;
+            }
 
-            const QString addonFilePath = CheckThread::getAddonFilePath(mDataDir, addon + ".py");
-            if (addonFilePath.isEmpty())
+            const QString addonFilePath = CheckThread::getAddonFilePath(mDataDir, addon_name + ".py");
+            if (addonFilePath.isEmpty()) {
+                emit showCheckError(addon_name + "-error",
+                                    tr("Addon error"),
+                                    tr("Addon file %1 is not available.\n%2 addon will be disabled for current check.").arg(addonFilePath).arg(addon_name));
+                disabled_addons.append(addon_name);
                 continue;
+            }
 
             if (dumpFile.isEmpty()) {
                 const std::string buildDir = mCppcheck.settings().buildDir;
@@ -296,32 +312,27 @@ void CheckThread::runAddonsAndTools(const ImportProject::FileSettings *fileSetti
                 mCppcheck.settings().buildDir = buildDir;
             }
 
-            QStringList args;
-            args << addonFilePath << "--cli" << dumpFile;
-            if (addon == "misra" && !mMisraFile.isEmpty() && QFileInfo(mMisraFile).exists()) {
-                if (mMisraFile.endsWith(".pdf", Qt::CaseInsensitive))
-                    args << "--misra-pdf=" + mMisraFile;
-                else
-                    args << "--rule-texts=" + mMisraFile;
-            }
-            qDebug() << python << args;
+            try {
+                auto addon = Addon(addonFilePath.toStdString(), mCppcheck.settings().exename);
+                if (addon_name == "misra" && !mMisraFile.isEmpty() && QFileInfo(mMisraFile).exists())
+                    addon.appendArgs("--rule-texts=" + mMisraFile.toStdString());
 
-            QProcess process;
-            QProcessEnvironment env = process.processEnvironment();
-            if (!env.contains("PYTHONHOME") && !python.startsWith("python")) {
-                env.insert("PYTHONHOME", QFileInfo(python).canonicalPath());
-                process.setProcessEnvironment(env);
-            }
-            process.start(python, args);
-            process.waitForFinished();
-            const QString output(process.readAllStandardOutput());
-            QFile f(dumpFile + '-' + addon + "-results");
-            if (f.open(QIODevice::WriteOnly | QIODevice::Text)) {
-                QTextStream out(&f);
-                out << output;
-                f.close();
+                // Set appropriate PYTHONPATH if user was choice non-standard value in settings
+                QProcess process;
+                QProcessEnvironment env = process.processEnvironment();
+                if (!env.contains("PYTHONHOME") && !python.startsWith("python"))
+                    addon.setEnv("PYTHONHOME", QFileInfo(python).canonicalPath().toStdString());
+
+                auto results = QString::fromStdString(addon.execute(dumpFile.toStdString()));
+                parseAddonErrors(results, addon_name);
+            } catch (const InternalError &e) {
+                emit showCheckError(addon_name + "-error",
+                                    tr("Addon error"),
+
+                                    tr("There is some problems with '%1' addon: %2.\nIt will be disabled for current check.").arg(QString::fromStdString(e.errorMessage)));
+                disabled_addons.append(addon_name);
+                continue;
             }
-            parseAddonErrors(output, addon);
         }
     }
 }
@@ -332,7 +343,7 @@ void CheckThread::stop()
     mCppcheck.terminate();
 }
 
-void CheckThread::parseAddonErrors(QString err, const QString &tool)
+void CheckThread::parseAddonErrors(QString &err, const QString &tool)
 {
     Q_UNUSED(tool);
     QTextStream in(&err, QIODevice::ReadOnly);
diff --git a/gui/checkthread.h b/gui/checkthread.h
index c92ff2d4af1..8258f5645cf 100644
--- a/gui/checkthread.h
+++ b/gui/checkthread.h
@@ -114,6 +114,10 @@ class CheckThread : public QThread {
     void done();
 
     void fileChecked(const QString &file);
+
+    /** @brief Show error occurred during check. */
+    void showCheckError(const QString &id, const QString &title, const QString &text, bool once = true);
+
 protected:
 
     /**
@@ -144,7 +148,13 @@ class CheckThread : public QThread {
 private:
     void runAddonsAndTools(const ImportProject::FileSettings *fileSettings, const QString &fileName);
 
-    void parseAddonErrors(QString err, const QString &tool);
+    /**
+     * @brief Fill GUI representation with errors from addon output
+     * @param err Addon output
+     * @param tool Name of addon
+     */
+    void parseAddonErrors(QString &err, const QString &tool);
+
     void parseClangErrors(const QString &tool, const QString &file0, QString err);
 
     bool isSuppressed(const Suppressions::ErrorMessage &errorMessage) const;
diff --git a/gui/threadhandler.cpp b/gui/threadhandler.cpp
index 103da76315f..4a32305564a 100644
--- a/gui/threadhandler.cpp
+++ b/gui/threadhandler.cpp
@@ -131,6 +131,8 @@ void ThreadHandler::setThreadCount(const int count)
                 this, &ThreadHandler::threadDone);
         connect(mThreads.last(), &CheckThread::fileChecked,
                 &mResults, &ThreadResult::fileChecked);
+        connect(mThreads.last(), &CheckThread::showCheckError,
+                &mResults, &ThreadResult::showCheckError);
     }
 }
 
@@ -143,6 +145,8 @@ void ThreadHandler::removeThreads()
                    this, &ThreadHandler::threadDone);
         disconnect(mThreads[i], &CheckThread::fileChecked,
                    &mResults, &ThreadResult::fileChecked);
+        disconnect(mThreads[i], &CheckThread::showCheckError,
+                   &mResults, &ThreadResult::showCheckError);
         delete mThreads[i];
     }
 
diff --git a/gui/threadresult.cpp b/gui/threadresult.cpp
index 0bc894f8081..943e0599416 100644
--- a/gui/threadresult.cpp
+++ b/gui/threadresult.cpp
@@ -22,6 +22,8 @@
 #include <QList>
 #include <QStringList>
 #include <QDebug>
+#include <QMessageBox>
+#include <QSet>
 #include "common.h"
 #include "erroritem.h"
 #include "errorlogger.h"
@@ -57,6 +59,14 @@ void ThreadResult::fileChecked(const QString &file)
     }
 }
 
+void ThreadResult::showCheckError(const QString &id, const QString &title, const QString &text, bool once)
+{
+    if (!mShownErrorIds.contains(id) || !once) {
+        mShownErrorIds.insert(id);
+        QMessageBox::critical(NULL, title, text);
+    }
+}
+
 void ThreadResult::reportErr(const ErrorLogger::ErrorMessage &msg)
 {
     QMutexLocker locker(&mutex);
diff --git a/gui/threadresult.h b/gui/threadresult.h
index 693dd8cb229..5c78720373a 100644
--- a/gui/threadresult.h
+++ b/gui/threadresult.h
@@ -23,6 +23,7 @@
 #include <QMutex>
 #include <QObject>
 #include <QStringList>
+#include <QSet>
 #include "errorlogger.h"
 #include "importproject.h"
 
@@ -82,6 +83,16 @@ public slots:
     * @param file File that is checked
     */
     void fileChecked(const QString &file);
+
+    /**
+     * @brief Display an error occurred during check.
+     * @param id Unique error identifier
+     * @param title Error title
+     * @param text Error text
+     * @param once If true, show error with this identifier only once
+     */
+    void showCheckError(const QString &id, const QString &title, const QString &text, bool once = true);
+
 signals:
     /**
     * @brief Progress signal
@@ -150,6 +161,11 @@ public slots:
     *
     */
     unsigned long mTotalFiles;
+
+    /**
+     * @brief Identifiers of errors occurred during check that has been shown.
+     */
+    QSet<QString> mShownErrorIds;
 };
 /// @}
 #endif // THREADRESULT_H
diff --git a/lib/addonutils.cpp b/lib/addonutils.cpp
new file mode 100644
index 00000000000..e361cd3c14d
--- /dev/null
+++ b/lib/addonutils.cpp
@@ -0,0 +1,189 @@
+/*
+ * Cppcheck - A tool for static C/C++ code analysis
+ * Copyright (C) 2007-2019 Cppcheck team.
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+#include "addonutils.h"
+
+#include "path.h"
+#include "utils.h"
+
+#define PICOJSON_USE_INT64
+#include <picojson.h>
+#include <fstream>
+#include <memory>
+#include <string>
+#include <sstream>
+
+static inline void throwAddonError(const std::string &msg)
+{
+    throw InternalError(nullptr, msg, InternalError::ADDON_ERROR);
+}
+
+Addon::Addon(const std::string &addonFileName, const std::string &exename)
+    : mArgs("")
+{
+    getAddonInfo(addonFileName, exename);
+}
+
+Addon::~Addon() {}
+
+void Addon::getAddonInfo(const std::string &fileName, const std::string &exename)
+{
+    if (fileName.find(".") == std::string::npos)
+        return getAddonInfo(fileName + ".py", exename);
+
+    if (endsWith(fileName, ".py", 3)) {
+        mScriptFile = getFullPath(fileName, exename);
+        if (mScriptFile.empty())
+            throwAddonError("Did not find addon " + fileName);
+
+        std::string::size_type pos1 = mScriptFile.rfind("/");
+        if (pos1 == std::string::npos)
+            pos1 = 0;
+        else
+            pos1++;
+        std::string::size_type pos2 = mScriptFile.rfind(".");
+        if (pos2 < pos1)
+            pos2 = std::string::npos;
+        mName = mScriptFile.substr(pos1, pos2 - pos1);
+
+        return;
+    } else {
+        if (!endsWith(fileName, ".json", 5))
+            throwAddonError("Failed to open addon " + fileName);
+
+        std::ifstream fin(fileName);
+        if (!fin.is_open())
+            throwAddonError("Failed to open " + fileName);
+
+        picojson::value json;
+        fin >> json;
+        if (!json.is<picojson::object>())
+            throwAddonError("Loading " + fileName + " failed. Bad json.");
+        picojson::object obj = json.get<picojson::object>();
+        if (obj.count("args")) {
+            if (!obj["args"].is<picojson::array>())
+                throwAddonError("Loading " + fileName + " failed. args must be array.");
+            for (const picojson::value &v : obj["args"].get<picojson::array>())
+                mArgs += " " + v.get<std::string>();
+        }
+
+        return getAddonInfo(obj["script"].get<std::string>(), exename);
+    }
+}
+
+void Addon::appendArgs(const std::string &arg)
+{
+    if (arg.empty())
+        return;
+
+    if (arg[0] != ' ')
+        mArgs.append(' ' + arg);
+    else
+        mArgs.append(arg);
+}
+
+void Addon::setEnv(const std::string &variable, const std::string &value)
+{
+    if (variable.empty())
+        return;
+    mEnv[variable] = value;
+}
+
+void Addon::clearEnv()
+{
+    mEnv.clear();
+}
+
+std::string Addon::getFullPath(const std::string &fileName, const std::string &exename) const
+{
+    if (Path::fileExists(fileName))
+        return fileName;
+
+    const std::string exepath = Path::getPathFromFilename(exename);
+    if (Path::fileExists(exepath + fileName))
+        return exepath + fileName;
+    if (Path::fileExists(exepath + "addons/" + fileName))
+        return exepath + "addons/" + fileName;
+
+#ifdef FILESDIR
+    if (Path::fileExists(FILESDIR + ("/" + fileName)))
+        return FILESDIR + ("/" + fileName);
+    if (Path::fileExists(FILESDIR + ("/addons/" + fileName)))
+        return FILESDIR + ("/addons/" + fileName);
+#endif
+    return "";
+}
+
+std::string Addon::getEnvString() const
+{
+    std::string result = "";
+    for (auto const &var : mEnv)
+        result += (var.first + "=" + var.second + " ");
+    return result;
+}
+
+std::string Addon::execute(const std::string &dumpFile) const
+{
+    const std::string cmd = getEnvString() + "python \"" + mScriptFile + "\" --cli" + mArgs + " \"" + dumpFile + "\"";
+
+#ifdef _WIN32
+    std::unique_ptr<FILE, decltype(&_pclose)> pipe(_popen(cmd.c_str(), "r"), _pclose);
+#else
+    std::unique_ptr<FILE, decltype(&pclose)> pipe(popen(cmd.c_str(), "r"), pclose);
+#endif
+    if (!pipe)
+        return "";
+    char buffer[1024];
+    std::string result;
+    while (fgets(buffer, sizeof(buffer), pipe.get()) != nullptr) {
+        result += buffer;
+    }
+    return result;
+}
+
+std::unique_ptr<ErrorLogger::ErrorMessage> Addon::getErrorMessage(const std::string &line) const
+{
+    if (line.compare(0,1,"{") != 0)
+        return nullptr;
+
+    picojson::value res;
+    std::istringstream istr2(line);
+    istr2 >> res;
+    if (!res.is<picojson::object>())
+        return nullptr;
+
+    picojson::object obj = res.get<picojson::object>();
+
+    const std::string fileName = obj["file"].get<std::string>();
+    const int64_t lineNumber = obj["linenr"].get<int64_t>();
+    const int64_t column = obj["column"].get<int64_t>();
+
+    std::unique_ptr<ErrorLogger::ErrorMessage> errmsg(new(ErrorLogger::ErrorMessage));
+
+    errmsg->callStack.emplace_back(ErrorLogger::ErrorMessage::FileLocation(fileName, lineNumber, column));
+
+    errmsg->id = obj["addon"].get<std::string>() + "-" + obj["errorId"].get<std::string>();
+    const std::string text = obj["message"].get<std::string>();
+    errmsg->setmsg(text);
+    const std::string severity = obj["severity"].get<std::string>();
+    errmsg->severity = Severity::fromString(severity);
+    if (errmsg->severity == Severity::SeverityType::none)
+        return nullptr;
+    errmsg->file0 = fileName;
+
+    return errmsg;
+}
\ No newline at end of file
diff --git a/lib/addonutils.h b/lib/addonutils.h
new file mode 100644
index 00000000000..133107a5a07
--- /dev/null
+++ b/lib/addonutils.h
@@ -0,0 +1,115 @@
+/*
+ * Cppcheck - A tool for static C/C++ code analysis
+ * Copyright (C) 2007-2019 Cppcheck team.
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+#ifndef ADDONUTILS_H
+#define ADDONUTILS_H
+
+#include "errorlogger.h"
+#include "path.h"
+
+#include <map>
+#include <memory>
+#include <string>
+
+/**
+ * @brief Class that represent Cppcheck addon -- external Python scipt that executed through Cppcheck.
+ *
+ * Addons can be configured through JSON files which contains path to script and additional arguments.
+ */
+class CPPCHECKLIB Addon {
+
+    friend class TestAddonUtils;
+
+public:
+    /**
+     * @param addonFileName Path to addon script file with .py or .json extension
+     * @param exename Path to Cppcheck executable
+     */
+    Addon(const std::string &addonFileName, const std::string &exename);
+    ~Addon();
+
+    /**
+     * @brief Execute addon.
+     * @param dumpFile Path to .dump file generated by cppcheck
+     * @return Addon output.
+     */
+    std::string execute(const std::string &dumpFile) const;
+
+    /**
+     * @brief Geneate ErrorMessage object from input line
+     * @param line Line generated due addon execution
+     * @return Pointer to ErrorMessage object if input contains error message, nullptr otherwise
+     *
+     * TODO: Replace with std::optional when switching to C++17.
+     */
+    std::unique_ptr<ErrorLogger::ErrorMessage> getErrorMessage(const std::string &line) const;
+
+    /**
+     * @brief Add command line arguments to addon execution
+     * @param arg Argument to add
+     */
+    void appendArgs(const std::string &arg);
+
+    /**
+     * @brief Set value for environment variable used in addon execution
+     * @param variable environment variable
+     * @param value value to set
+     */
+    void setEnv(const std::string &variable, const std::string &value);
+
+    /**
+     * @brief Remove all environment settings
+     */
+    void clearEnv();
+
+private:
+    /**
+     * @brief Initialization helper used to set addon configuration properely.
+     * @param fileName Path to addon file. Both .py and .json addons are supported.
+     * @param exename Path to Cppcheck executable
+     */
+    void getAddonInfo(const std::string &fileName, const std::string &exename);
+
+    /**
+     * @brief Return absolute path to a addon file with respect of addons configuration.
+     * @param fileName Path to the file to check.
+     * @param exename Path to Cppcheck executable
+     * @return Absolute path to a addon file if success, empty string otherwise
+     */
+    std::string getFullPath(const std::string &fileName, const std::string &exename) const;
+
+    /**
+     * @brief Generate string with environment variables
+     * @return Space-separated string with variables in following format: "VAR1=21 VAR2=42"
+     */
+    std::string getEnvString() const;
+
+private:
+    /** @brief Name of addon. */
+    std::string mName;
+
+    /** @brief Absolute path to addon script file */
+    std::string mScriptFile;
+
+    /** @brief Additional command line arguments */
+    std::string mArgs;
+
+    /** @brief Environment variables for addons execution. */
+    std::map<std::string, std::string> mEnv;
+};
+
+#endif // ADDONUTILS_H
\ No newline at end of file
diff --git a/lib/cppcheck.cpp b/lib/cppcheck.cpp
index 7d4bce36e62..a0afb6a65e3 100644
--- a/lib/cppcheck.cpp
+++ b/lib/cppcheck.cpp
@@ -17,6 +17,7 @@
  */
 #include "cppcheck.h"
 
+#include "addonutils.h"
 #include "check.h"
 #include "checkunusedfunctions.h"
 #include "ctu.h"
@@ -34,8 +35,6 @@
 
 #include "exprengine.h"
 
-#define PICOJSON_USE_INT64
-#include <picojson.h>
 #include <simplecpp.h>
 #include <tinyxml2.h>
 #include <algorithm>
@@ -60,95 +59,6 @@ static TimerResults S_timerResults;
 // CWE ids used
 static const CWE CWE398(398U);  // Indicator of Poor Code Quality
 
-namespace {
-    struct AddonInfo {
-        std::string name;
-        std::string scriptFile;
-        std::string args;
-
-        static std::string getFullPath(const std::string &fileName, const std::string &exename) {
-            if (Path::fileExists(fileName))
-                return fileName;
-
-            const std::string exepath = Path::getPathFromFilename(exename);
-            if (Path::fileExists(exepath + fileName))
-                return exepath + fileName;
-            if (Path::fileExists(exepath + "addons/" + fileName))
-                return exepath + "addons/" + fileName;
-
-#ifdef FILESDIR
-            if (Path::fileExists(FILESDIR + ("/" + fileName)))
-                return FILESDIR + ("/" + fileName);
-            if (Path::fileExists(FILESDIR + ("/addons/" + fileName)))
-                return FILESDIR + ("/addons/" + fileName);
-#endif
-            return "";
-        }
-
-        std::string getAddonInfo(const std::string &fileName, const std::string &exename) {
-            if (fileName.find(".") == std::string::npos)
-                return getAddonInfo(fileName + ".py", exename);
-
-            if (endsWith(fileName, ".py", 3)) {
-                scriptFile = getFullPath(fileName, exename);
-                if (scriptFile.empty())
-                    return "Did not find addon " + fileName;
-
-                std::string::size_type pos1 = scriptFile.rfind("/");
-                if (pos1 == std::string::npos)
-                    pos1 = 0;
-                else
-                    pos1++;
-                std::string::size_type pos2 = scriptFile.rfind(".");
-                if (pos2 < pos1)
-                    pos2 = std::string::npos;
-                name = scriptFile.substr(pos1, pos2 - pos1);
-
-                return "";
-            }
-
-            if (!endsWith(fileName, ".json", 5))
-                return "Failed to open addon " + fileName;
-
-            std::ifstream fin(fileName);
-            if (!fin.is_open())
-                return "Failed to open " + fileName;
-            picojson::value json;
-            fin >> json;
-            if (!json.is<picojson::object>())
-                return "Loading " + fileName + " failed. Bad json.";
-            picojson::object obj = json.get<picojson::object>();
-            if (obj.count("args")) {
-                if (!obj["args"].is<picojson::array>())
-                    return "Loading " + fileName + " failed. args must be array.";
-                for (const picojson::value &v : obj["args"].get<picojson::array>())
-                    args += " " + v.get<std::string>();
-            }
-
-            return getAddonInfo(obj["script"].get<std::string>(), exename);
-        }
-    };
-}
-
-static std::string executeAddon(const AddonInfo &addonInfo, const std::string &dumpFile)
-{
-    const std::string cmd = "python \"" + addonInfo.scriptFile + "\" --cli" + addonInfo.args + " \"" + dumpFile + "\"";
-
-#ifdef _WIN32
-    std::unique_ptr<FILE, decltype(&_pclose)> pipe(_popen(cmd.c_str(), "r"), _pclose);
-#else
-    std::unique_ptr<FILE, decltype(&pclose)> pipe(popen(cmd.c_str(), "r"), pclose);
-#endif
-    if (!pipe)
-        return "";
-    char buffer[1024];
-    std::string result;
-    while (fgets(buffer, sizeof(buffer), pipe.get()) != nullptr) {
-        result += buffer;
-    }
-    return result;
-}
-
 static std::vector<std::string> split(const std::string &str, const std::string &sep)
 {
     std::vector<std::string> ret;
@@ -609,48 +519,21 @@ unsigned int CppCheck::checkFile(const std::string& filename, const std::string
         if (!mSettings.addons.empty()) {
             fdump.close();
 
-            for (const std::string &addon : mSettings.addons) {
-                struct AddonInfo addonInfo;
-                const std::string &failedToGetAddonInfo = addonInfo.getAddonInfo(addon, mSettings.exename);
-                if (!failedToGetAddonInfo.empty()) {
-                    reportOut(failedToGetAddonInfo);
+            for (const std::string &addon_file : mSettings.addons) {
+                try {
+                    auto addon = Addon(addon_file, mSettings.exename);
+                    const std::string results = addon.execute(dumpFile);
+                    std::istringstream istr(results);
+                    std::string line;
+                    while (std::getline(istr, line)) {
+                        auto errmsg = addon.getErrorMessage(line);
+                        if (errmsg)
+                            reportErr(*errmsg);
+                    }
+                } catch (const InternalError &e) {
+                    reportOut(e.errorMessage);
                     continue;
                 }
-                const std::string results = executeAddon(addonInfo, dumpFile);
-                std::istringstream istr(results);
-                std::string line;
-
-                while (std::getline(istr, line)) {
-                    if (line.compare(0,1,"{") != 0)
-                        continue;
-
-                    picojson::value res;
-                    std::istringstream istr2(line);
-                    istr2 >> res;
-                    if (!res.is<picojson::object>())
-                        continue;
-
-                    picojson::object obj = res.get<picojson::object>();
-
-                    const std::string fileName = obj["file"].get<std::string>();
-                    const int64_t lineNumber = obj["linenr"].get<int64_t>();
-                    const int64_t column = obj["column"].get<int64_t>();
-
-                    ErrorLogger::ErrorMessage errmsg;
-
-                    errmsg.callStack.emplace_back(ErrorLogger::ErrorMessage::FileLocation(fileName, lineNumber, column));
-
-                    errmsg.id = obj["addon"].get<std::string>() + "-" + obj["errorId"].get<std::string>();
-                    const std::string text = obj["message"].get<std::string>();
-                    errmsg.setmsg(text);
-                    const std::string severity = obj["severity"].get<std::string>();
-                    errmsg.severity = Severity::fromString(severity);
-                    if (errmsg.severity == Severity::SeverityType::none)
-                        continue;
-                    errmsg.file0 = fileName;
-
-                    reportErr(errmsg);
-                }
             }
         }
 
diff --git a/lib/cppcheck.vcxproj b/lib/cppcheck.vcxproj
index 470bcf4d1a5..46fba740703 100644
--- a/lib/cppcheck.vcxproj
+++ b/lib/cppcheck.vcxproj
@@ -38,6 +38,7 @@
     <ClCompile Include="..\externals\simplecpp\simplecpp.cpp" />
     <ClCompile Include="..\externals\tinyxml\tinyxml2.cpp" />
     <ClCompile Include="analyzerinfo.cpp" />
+    <ClCompile Include="addonutils.cpp" />
     <ClCompile Include="astutils.cpp" />
     <ClCompile Include="check.cpp">
       <PrecompiledHeader Condition="'$(Configuration)|$(Platform)'=='Release|x64'">Create</PrecompiledHeader>
@@ -101,6 +102,7 @@
     <ClInclude Include="..\externals\simplecpp\simplecpp.h" />
     <ClInclude Include="..\externals\tinyxml\tinyxml2.h" />
     <ClInclude Include="analyzerinfo.h" />
+    <ClInclude Include="addonutils.h" />
     <ClInclude Include="astutils.h" />
     <ClInclude Include="check.h" />
     <ClInclude Include="check64bit.h" />
diff --git a/lib/cppcheck.vcxproj.filters b/lib/cppcheck.vcxproj.filters
index f41796ad145..8e88b435802 100644
--- a/lib/cppcheck.vcxproj.filters
+++ b/lib/cppcheck.vcxproj.filters
@@ -137,6 +137,9 @@
     <ClCompile Include="astutils.cpp">
       <Filter>Source Files</Filter>
     </ClCompile>
+    <ClCompile Include="addonutils.cpp">
+      <Filter>Source Files</Filter>
+    </ClCompile>
     <ClCompile Include="checkfunctions.cpp">
       <Filter>Source Files</Filter>
     </ClCompile>
@@ -301,6 +304,9 @@
     <ClInclude Include="astutils.h">
       <Filter>Header Files</Filter>
     </ClInclude>
+    <ClInclude Include="addonutils.h">
+      <Filter>Header Files</Filter>
+    </ClInclude>
     <ClInclude Include="utils.h">
       <Filter>Header Files</Filter>
     </ClInclude>
diff --git a/lib/errorlogger.cpp b/lib/errorlogger.cpp
index 781f852b8f6..6b832d64c13 100644
--- a/lib/errorlogger.cpp
+++ b/lib/errorlogger.cpp
@@ -55,6 +55,9 @@ InternalError::InternalError(const Token *tok, const std::string &errorMsg, Type
     case INSTANTIATION:
         id = "instantiationError";
         break;
+    case ADDON_ERROR:
+        id = "addonError";
+        break;
     }
 }
 
diff --git a/lib/errorlogger.h b/lib/errorlogger.h
index c442c8620e5..2550505e7d5 100644
--- a/lib/errorlogger.h
+++ b/lib/errorlogger.h
@@ -54,7 +54,7 @@ namespace tinyxml2 {
 
 /** @brief Simple container to be thrown when internal error is detected. */
 struct InternalError {
-    enum Type {AST, SYNTAX, UNKNOWN_MACRO, INTERNAL, LIMIT, INSTANTIATION};
+    enum Type {AST, SYNTAX, UNKNOWN_MACRO, INTERNAL, LIMIT, INSTANTIATION, ADDON_ERROR};
     InternalError(const Token *tok, const std::string &errorMsg, Type type = INTERNAL);
     const Token *token;
     std::string errorMessage;
diff --git a/lib/lib.pri b/lib/lib.pri
index f689e528996..cfe91f4cbe8 100644
--- a/lib/lib.pri
+++ b/lib/lib.pri
@@ -3,7 +3,8 @@
 include($$PWD/pcrerules.pri)
 include($$PWD/../externals/externals.pri)
 INCLUDEPATH += $$PWD
-HEADERS += $${PWD}/analyzerinfo.h \
+HEADERS += $${PWD}/addonutils.h \
+           $${PWD}/analyzerinfo.h \
            $${PWD}/astutils.h \
            $${PWD}/check.h \
            $${PWD}/check64bit.h \
@@ -54,7 +55,8 @@ HEADERS += $${PWD}/analyzerinfo.h \
            $${PWD}/tokenlist.h \
            $${PWD}/valueflow.h
 
-SOURCES += $${PWD}/analyzerinfo.cpp \
+SOURCES += $${PWD}/addonutils.cpp \
+           $${PWD}/analyzerinfo.cpp \
            $${PWD}/astutils.cpp \
            $${PWD}/check.cpp \
            $${PWD}/check64bit.cpp \
diff --git a/test/testaddonutils.cpp b/test/testaddonutils.cpp
new file mode 100644
index 00000000000..f56b67d5f61
--- /dev/null
+++ b/test/testaddonutils.cpp
@@ -0,0 +1,152 @@
+/*
+ * Cppcheck - A tool for static C/C++ code analysis
+ * Copyright (C) 2007-2019 Cppcheck team.
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+#include "addonutils.h"
+#include "settings.h"
+#include "testsuite.h"
+
+#ifdef _WIN32
+#include <windows.h>
+#endif // _WIN32
+
+#include <fstream>
+#include <cstdio>
+
+class TestAddonUtils : public TestFixture {
+public:
+    TestAddonUtils() : TestFixture("TestAddonUtils") {}
+
+private:
+    Settings settings;
+
+    void run() OVERRIDE {
+        settings.exename = "cppcheck";
+#ifdef _WIN32
+        settings.exename += ".exe";
+#endif // _WIN32
+
+        TEST_CASE(testConstructors);
+        TEST_CASE(testConstructorsJson);
+        TEST_CASE(testBrokenJson);
+        TEST_CASE(testAppendArgs);
+        TEST_CASE(testEnv);
+    }
+
+    void testConstructors() const
+    {
+        ASSERT_NO_THROW(Addon("misra.py", settings.exename));
+        ASSERT_NO_THROW(Addon("naming.py", settings.exename));
+        ASSERT_NO_THROW(Addon("y2038.py", settings.exename));
+        ASSERT_NO_THROW(Addon("cert.py", settings.exename));
+
+        ASSERT_NO_THROW(Addon("misra", settings.exename));
+        ASSERT_NO_THROW(Addon("naming", settings.exename));
+        ASSERT_NO_THROW(Addon("y2038", settings.exename));
+        ASSERT_NO_THROW(Addon("cert", settings.exename));
+
+        ASSERT_NO_THROW(Addon("naming.json", settings.exename));
+
+        // cppcheck-suppress unusedScopedObject
+        ASSERT_THROW(Addon("misra.foo", settings.exename), InternalError);
+        // cppcheck-suppress unusedScopedObject
+        ASSERT_THROW(Addon("misra.", settings.exename), InternalError);
+        // cppcheck-suppress unusedScopedObject
+        ASSERT_THROW(Addon(".py", settings.exename), InternalError);
+        // cppcheck-suppress unusedScopedObject
+        ASSERT_THROW(Addon(".", settings.exename), InternalError);
+        // cppcheck-suppress unusedScopedObject
+        ASSERT_THROW(Addon("", settings.exename), InternalError);
+        // cppcheck-suppress unusedScopedObject
+        ASSERT_THROW(Addon("/dev/null", settings.exename), InternalError);
+    }
+
+    void testConstructorsJson() const
+    {
+        // cppcheck-suppress unusedScopedObject
+        ASSERT_THROW(Addon("test_addon.json", settings.exename), InternalError);
+
+        std::ofstream test_addon { "test_addon.json" };
+        test_addon << "{ \"script\": \"addons/misra.py\" }" << std::endl;
+        ASSERT_NO_THROW(Addon("test_addon.json", settings.exename));
+#ifdef _WIN32
+        DeleteFile("test_addon.json");
+#else
+        std::remove("test_addon.json");
+#endif // _WIN32
+
+        // cppcheck-suppress unusedScopedObject
+        ASSERT_THROW(Addon("test_addon.json", settings.exename), InternalError);
+    }
+
+    void testBrokenJson() const
+    {
+        {
+            std::ofstream test_addon { "test_addon_broken.json" };
+            test_addon << "{ \"script\": \"addons/misra.py }" << std::endl; // missing quote
+            // cppcheck-suppress unusedScopedObject
+            ASSERT_THROW(Addon("test_addon_broken.json", settings.exename), InternalError);
+#ifdef _WIN32
+        DeleteFile("test_addon_broken.json");
+#else
+        std::remove("test_addon_broken.json");
+#endif // _WIN32
+        }
+
+        {
+            std::ofstream test_addon { "test_addon_broken.json" };
+            test_addon << "{ \"script\": \"addons/misra.py \"" << std::endl; // missing }
+            // cppcheck-suppress unusedScopedObject
+            ASSERT_THROW(Addon("test_addon_broken.json", settings.exename), InternalError);
+#ifdef _WIN32
+        DeleteFile("test_addon_broken.json");
+#else
+        std::remove("test_addon_broken.json");
+#endif // _WIN32
+        }
+    }
+
+    void testAppendArgs() const
+    {
+        auto addon = Addon("misra.py", settings.exename);
+        auto saved_args = addon.mArgs;
+
+        addon.appendArgs("");
+        ASSERT_EQUALS(saved_args, addon.mArgs);
+
+        addon.appendArgs("--arg1");
+        ASSERT_EQUALS(addon.mArgs[0], ' ');
+    }
+
+    void testEnv() const
+    {
+        auto addon = Addon("misra.py", settings.exename);
+
+        ASSERT_EQUALS(addon.getEnvString(), "");
+
+        addon.setEnv("VAR1", "21");
+        ASSERT_EQUALS(addon.getEnvString(), "VAR1=21 ");
+        addon.setEnv("VAR2", "42");
+        ASSERT_EQUALS(addon.getEnvString(), "VAR1=21 VAR2=42 ");
+        addon.setEnv("VAR1", "42");
+        ASSERT_EQUALS(addon.getEnvString(), "VAR1=42 VAR2=42 ");
+
+        addon.clearEnv();
+        ASSERT_EQUALS(addon.getEnvString(), "");
+    }
+};
+
+REGISTER_TEST(TestAddonUtils)
diff --git a/test/testrunner.vcxproj b/test/testrunner.vcxproj
index d37a615042d..9f987841002 100755
--- a/test/testrunner.vcxproj
+++ b/test/testrunner.vcxproj
@@ -1,4 +1,4 @@
-<?xml version="1.0" encoding="utf-8"?>
+<?xml version="1.0" encoding="utf-8"?>
 <Project DefaultTargets="Build" ToolsVersion="15.0" xmlns="http://schemas.microsoft.com/developer/msbuild/2003">
   <ItemGroup Label="ProjectConfigurations">
     <ProjectConfiguration Include="Debug|Win32">
@@ -33,6 +33,7 @@
     <ClCompile Include="test64bit.cpp" />
     <ClCompile Include="testassert.cpp" />
     <ClCompile Include="testastutils.cpp" />
+    <ClCompile Include="testaddonutils.cpp" />
     <ClCompile Include="testautovariables.cpp" />
     <ClCompile Include="testbool.cpp" />
     <ClCompile Include="testboost.cpp" />
diff --git a/test/testrunner.vcxproj.filters b/test/testrunner.vcxproj.filters
index 9c413e6e9af..4af6bd6b639 100644
--- a/test/testrunner.vcxproj.filters
+++ b/test/testrunner.vcxproj.filters
@@ -208,6 +208,9 @@
     <ClCompile Include="testastutils.cpp">
       <Filter>Source Files</Filter>
     </ClCompile>
+    <ClCompile Include="testaddonutils.cpp">
+      <Filter>Source Files</Filter>
+    </ClCompile>
     <ClCompile Include="..\lib\astutils.cpp">
       <Filter>Source Files</Filter>
     </ClCompile>