greatly improved `Settings::loadCppcheckCfg()` error handling (#5712)

This also fixes the issue that `cppcheck.cfg` is no longer being loaded
from executable path. That was introduced by #5704.

.github/workflows/cppcheck-premium.yml

@@ -40,4 +40,4 @@ jobs:
       - name: Check
         run: |
           cppcheckpremium-${{ env.PREMIUM_VERSION }}/premiumaddon --check-loc-license cppcheck.lic > cppcheck-premium-loc
-          cppcheckpremium-${{ env.PREMIUM_VERSION }}/cppcheck -j$(nproc) -D__GNUC__ -D__CPPCHECK__ --suppressions-list=cppcheckpremium-suppressions --platform=unix64 --enable=style --premium=misra-c++-2008 --premium=cert-c++-2016 --error-exitcode=1 lib
+          cppcheckpremium-${{ env.PREMIUM_VERSION }}/cppcheck -j$(nproc) -D__GNUC__ -D__CPPCHECK__ --suppressions-list=cppcheckpremium-suppressions --platform=unix64 --enable=style --premium=misra-c++-2008 --premium=cert-c++-2016 --inline-suppr --error-exitcode=1 lib

Makefile

@@ -728,7 +728,7 @@ test/testclangimport.o: test/testclangimport.cpp lib/addoninfo.h lib/check.h lib
 test/testclass.o: test/testclass.cpp externals/simplecpp/simplecpp.h lib/addoninfo.h lib/check.h lib/checkclass.h lib/color.h lib/config.h lib/errorlogger.h lib/errortypes.h lib/library.h lib/mathlib.h lib/platform.h lib/preprocessor.h lib/settings.h lib/sourcelocation.h lib/standards.h lib/suppressions.h lib/symboldatabase.h lib/templatesimplifier.h lib/token.h lib/tokenize.h lib/tokenlist.h lib/utils.h lib/vfvalue.h test/fixture.h test/helpers.h
 	$(CXX) ${INCLUDE_FOR_TEST} $(CPPFLAGS) $(CXXFLAGS) -c -o $@ test/testclass.cpp
 
-test/testcmdlineparser.o: test/testcmdlineparser.cpp cli/cmdlinelogger.h cli/cmdlineparser.h cli/cppcheckexecutor.h lib/addoninfo.h lib/check.h lib/color.h lib/config.h lib/errorlogger.h lib/errortypes.h lib/filesettings.h lib/library.h lib/mathlib.h lib/platform.h lib/settings.h lib/standards.h lib/suppressions.h lib/timer.h lib/tokenize.h lib/tokenlist.h lib/utils.h test/fixture.h test/helpers.h test/redirect.h
+test/testcmdlineparser.o: test/testcmdlineparser.cpp cli/cmdlinelogger.h cli/cmdlineparser.h cli/cppcheckexecutor.h lib/addoninfo.h lib/check.h lib/color.h lib/config.h lib/errorlogger.h lib/errortypes.h lib/filesettings.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/tokenize.h lib/tokenlist.h lib/utils.h test/fixture.h test/helpers.h test/redirect.h
 	$(CXX) ${INCLUDE_FOR_TEST} $(CPPFLAGS) $(CXXFLAGS) -c -o $@ test/testcmdlineparser.cpp
 
 test/testcolor.o: test/testcolor.cpp lib/addoninfo.h lib/check.h lib/color.h lib/config.h lib/errorlogger.h lib/errortypes.h lib/library.h lib/mathlib.h lib/platform.h lib/settings.h lib/standards.h lib/suppressions.h lib/utils.h test/fixture.h
@@ -809,7 +809,7 @@ test/testpreprocessor.o: test/testpreprocessor.cpp externals/simplecpp/simplecpp
 test/testprocessexecutor.o: test/testprocessexecutor.cpp cli/executor.h cli/processexecutor.h lib/addoninfo.h lib/analyzerinfo.h lib/check.h lib/color.h lib/config.h lib/cppcheck.h lib/errorlogger.h lib/errortypes.h lib/filesettings.h lib/library.h lib/mathlib.h lib/platform.h lib/settings.h lib/standards.h lib/suppressions.h lib/timer.h lib/tokenize.h lib/tokenlist.h lib/utils.h test/fixture.h test/helpers.h test/redirect.h
 	$(CXX) ${INCLUDE_FOR_TEST} $(CPPFLAGS) $(CXXFLAGS) -c -o $@ test/testprocessexecutor.cpp
 
-test/testsettings.o: test/testsettings.cpp lib/addoninfo.h lib/check.h lib/color.h lib/config.h lib/errorlogger.h lib/errortypes.h lib/library.h lib/mathlib.h lib/platform.h lib/settings.h lib/standards.h lib/suppressions.h lib/utils.h test/fixture.h
+test/testsettings.o: test/testsettings.cpp lib/addoninfo.h lib/check.h lib/color.h lib/config.h lib/errorlogger.h lib/errortypes.h lib/library.h lib/mathlib.h lib/platform.h lib/settings.h lib/standards.h lib/suppressions.h lib/tokenize.h lib/tokenlist.h lib/utils.h test/fixture.h test/helpers.h
 	$(CXX) ${INCLUDE_FOR_TEST} $(CPPFLAGS) $(CXXFLAGS) -c -o $@ test/testsettings.cpp
 
 test/testsimplifytemplate.o: test/testsimplifytemplate.cpp lib/addoninfo.h lib/check.h lib/color.h lib/config.h lib/errorlogger.h lib/errortypes.h lib/library.h lib/mathlib.h lib/platform.h lib/settings.h lib/standards.h lib/suppressions.h lib/templatesimplifier.h lib/token.h lib/tokenize.h lib/tokenlist.h lib/utils.h lib/vfvalue.h test/fixture.h

cli/cmdlineparser.cpp

@@ -282,6 +282,8 @@ bool CmdLineParser::fillSettingsFromArgs(int argc, const char* const argv[])
 // TODO: error out on all missing given files/paths
 CmdLineParser::Result CmdLineParser::parseFromArgs(int argc, const char* const argv[])
 {
+    mSettings.exename = Path::getCurrentExecutablePath(argv[0]);
+
     if (argc <= 1) {
         printHelp();
         return Result::Exit;
@@ -307,7 +309,8 @@ CmdLineParser::Result CmdLineParser::parseFromArgs(int argc, const char* const a
 
         // print all possible error messages..
         if (std::strcmp(argv[i], "--errorlist") == 0) {
-            mSettings.loadCppcheckCfg();
+            if (!loadCppcheckCfg())
+                return Result::Fail;
             {
                 XMLErrorMessagesLogger xmlLogger;
                 std::cout << ErrorMessage::getXMLHeader(mSettings.cppcheckCfgProductName);
@@ -324,7 +327,8 @@ CmdLineParser::Result CmdLineParser::parseFromArgs(int argc, const char* const a
         }
 
         if (std::strcmp(argv[i], "--version") == 0) {
-            mSettings.loadCppcheckCfg();
+            if (!loadCppcheckCfg())
+                return Result::Fail;
             if (!mSettings.cppcheckCfgProductName.empty()) {
                 mLogger.printRaw(mSettings.cppcheckCfgProductName);
             } else {
@@ -343,8 +347,6 @@ CmdLineParser::Result CmdLineParser::parseFromArgs(int argc, const char* const a
 
     ImportProject project;
 
-    mSettings.exename = Path::getCurrentExecutablePath(argv[0]);
-
     for (int i = 1; i < argc; i++) {
         if (argv[i][0] == '-') {
             // User define
@@ -1203,7 +1205,8 @@ CmdLineParser::Result CmdLineParser::parseFromArgs(int argc, const char* const a
         }
     }
 
-    mSettings.loadCppcheckCfg();
+    if (!loadCppcheckCfg())
+        return Result::Fail;
 
     // Default template format..
     if (mSettings.templateFormat.empty()) {
@@ -1609,10 +1612,10 @@ void CmdLineParser::printHelp() const
     mLogger.printRaw(oss.str());
 }
 
-bool CmdLineParser::isCppcheckPremium() const {
-    if (mSettings.cppcheckCfgProductName.empty())
-        mSettings.loadCppcheckCfg();
-    return startsWith(mSettings.cppcheckCfgProductName, "Cppcheck Premium");
+bool CmdLineParser::isCppcheckPremium() {
+    Settings settings;
+    settings.loadCppcheckCfg(); // TODO: how to handle errors?
+    return startsWith(settings.cppcheckCfgProductName, "Cppcheck Premium");
 }
 
 bool CmdLineParser::tryLoadLibrary(Library& destination, const std::string& basepath, const char* filename)
@@ -1701,3 +1704,14 @@ bool CmdLineParser::loadAddons(Settings& settings)
     }
     return result;
 }
+
+bool CmdLineParser::loadCppcheckCfg()
+{
+    const std::string cfgErr = mSettings.loadCppcheckCfg();
+    if (!cfgErr.empty()) {
+        mLogger.printError("could not load cppcheck.cfg - " + cfgErr);
+        return false;
+    }
+    return true;
+}
+

cli/cmdlineparser.h

@@ -111,7 +111,7 @@ protected:
     void printHelp() const;
 
 private:
-    bool isCppcheckPremium() const;
+    static bool isCppcheckPremium();
 
     template<typename T>
     bool parseNumberArg(const char* const arg, std::size_t offset, T& num, bool mustBePositive = false)
@@ -150,6 +150,8 @@ private:
      */
     bool loadAddons(Settings& settings);
 
+    bool loadCppcheckCfg();
+
     CmdLineLogger &mLogger;
 
     std::vector<std::string> mPathNames;

gui/mainwindow.cpp

@@ -119,7 +119,7 @@ MainWindow::MainWindow(TranslationHandler* th, QSettings* settings) :
     {
         Settings tempSettings;
         tempSettings.exename = QCoreApplication::applicationFilePath().toStdString();
-        tempSettings.loadCppcheckCfg();
+        tempSettings.loadCppcheckCfg(); // TODO: how to handle error?
         mCppcheckCfgProductName = QString::fromStdString(tempSettings.cppcheckCfgProductName);
         mCppcheckCfgAbout = QString::fromStdString(tempSettings.cppcheckCfgAbout);
     }
@@ -903,8 +903,7 @@ bool MainWindow::tryLoadLibrary(Library *library, const QString& filename)
     return true;
 }
 
-Settings MainWindow::getCppcheckSettings()
-{
+Settings MainWindow::getCppcheckSettings() {
     saveSettings(); // Save settings
 
     Settings result;
@@ -915,7 +914,11 @@ Settings MainWindow::getCppcheckSettings()
     if (!std)
         QMessageBox::critical(this, tr("Error"), tr("Failed to load %1. Your Cppcheck installation is broken. You can use --data-dir=<directory> at the command line to specify where this file is located. Please note that --data-dir is supposed to be used by installation scripts and therefore the GUI does not start when it is used, all that happens is that the setting is configured.").arg("std.cfg"));
 
-    result.loadCppcheckCfg();
+    {
+        const QString cfgErr = QString::fromStdString(result.loadCppcheckCfg());
+        if (!cfgErr.isEmpty())
+            QMessageBox::critical(this, tr("Error"), tr("Failed to load %1 - %2").arg("cppcheck.cfg").arg(cfgErr));
+    }
 
     // If project file loaded, read settings from it
     if (mProjectFile) {

lib/settings.cpp

@@ -40,40 +40,87 @@ Settings::Settings()
     setCheckLevelNormal();
 }
 
-// TODO: report error when the config is invalid
-void Settings::loadCppcheckCfg()
+std::string Settings::loadCppcheckCfg()
 {
-    std::string fileName = Path::getPathFromFilename(exename) + "cppcheck.cfg";
+    static const std::string cfgFilename = "cppcheck.cfg";
+    std::string fileName;
 #ifdef FILESDIR
-    if (Path::isFile(FILESDIR "/cppcheck.cfg"))
-        fileName = FILESDIR "/cppcheck.cfg";
+    if (Path::isFile(Path::join(FILESDIR, cfgFilename)))
+        fileName = Path::join(FILESDIR, cfgFilename);
 #endif
+    // cppcheck-suppress knownConditionTrueFalse
+    if (fileName.empty()) {
+        fileName = Path::getPathFromFilename(exename) + cfgFilename;
+        if (!Path::isFile(fileName))
+            return "";
+    }
 
     std::ifstream fin(fileName);
     if (!fin.is_open())
-        return;
+        return "could not open file";
     picojson::value json;
     fin >> json;
-    if (!picojson::get_last_error().empty())
-        return;
-    picojson::object obj = json.get<picojson::object>();
-    if (obj.count("productName") && obj["productName"].is<std::string>())
-        cppcheckCfgProductName = obj["productName"].get<std::string>();
-    if (obj.count("about") && obj["about"].is<std::string>())
-        cppcheckCfgAbout = obj["about"].get<std::string>();
-    if (obj.count("addons") && obj["addons"].is<picojson::array>()) {
-        for (const picojson::value &v : obj["addons"].get<picojson::array>()) {
+    {
+        const std::string& lastErr = picojson::get_last_error();
+        if (!lastErr.empty())
+            return "not a valid JSON - " + lastErr;
+    }
+    const picojson::object& obj = json.get<picojson::object>();
+    {
+        const picojson::object::const_iterator it = obj.find("productName");
+        if (it != obj.cend()) {
+            const auto& v = it->second;
+            if (!v.is<std::string>())
+                return "'productName' is not a string";
+            cppcheckCfgProductName = v.get<std::string>();
+        }
+    }
+    {
+        const picojson::object::const_iterator it = obj.find("about");
+        if (it != obj.cend()) {
+            const auto& v = it->second;
+            if (!v.is<std::string>())
+                return "'about' is not a string";
+            cppcheckCfgAbout = v.get<std::string>();
+        }
+    }
+    {
+        const picojson::object::const_iterator it = obj.find("addons");
+        if (it != obj.cend()) {
+            const auto& entry = it->second;
+            if (!entry.is<picojson::array>())
+                return "'addons' is not an array";
+            for (const picojson::value &v : entry.get<picojson::array>())
+            {
+                if (!v.is<std::string>())
+                    return "'addons' array entry is not a string";
                 const std::string &s = v.get<std::string>();
                 if (!Path::isAbsolute(s))
-                addons.emplace(Path::getPathFromFilename(fileName) + s);
+                    addons.emplace(Path::join(Path::getPathFromFilename(fileName), s));
                 else
                     addons.emplace(s);
             }
         }
-    if (obj.count("suppressions") && obj["suppressions"].is<picojson::array>()) {
-        for (const picojson::value &v : obj["suppressions"].get<picojson::array>())
-            nomsg.addSuppressionLine(v.get<std::string>());
     }
+    {
+        const picojson::object::const_iterator it = obj.find("suppressions");
+        if (it != obj.cend()) {
+            const auto& entry = it->second;
+            if (!entry.is<picojson::array>())
+                return "'suppressions' is not an array";
+            for (const picojson::value &v : entry.get<picojson::array>())
+            {
+                if (!v.is<std::string>())
+                    return "'suppressions' array entry is not a string";
+                const std::string &s = v.get<std::string>();
+                const std::string err = nomsg.addSuppressionLine(s);
+                if (!err.empty())
+                    return "could not parse suppression '" + s + "' - " + err;
+            }
+        }
+    }
+
+    return "";
 }
 
 std::string Settings::parseEnabled(const std::string &str, std::tuple<SimpleEnableGroup<Severity>, SimpleEnableGroup<Checks>> &groups)

lib/settings.h

@@ -99,7 +99,7 @@ private:
 public:
     Settings();
 
-    void loadCppcheckCfg();
+    std::string loadCppcheckCfg();
 
     /** @brief addons, either filename of python/json file or json data */
     std::unordered_set<std::string> addons;

releasenotes.txt

@@ -32,3 +32,4 @@ Other:
   - You can suppress all warnings where macro is used using "-macro"
 - fixed CMake build with UBSAN and GCC
 - Added command-line options "--fsigned-char" and "--funsigned-char" to control the signess of the "char" type. This overrides previously specified "--platform" options and is overrides by following ones.
+- An error is now reported when the "cppcheck.cfg" is invalid. The CLI version will also exit with a failure in that case.

test/testcmdlineparser.cpp

@@ -22,6 +22,7 @@
 #include "cppcheckexecutor.h"
 #include "errortypes.h"
 #include "helpers.h"
+#include "path.h"
 #include "platform.h"
 #include "redirect.h"
 #include "settings.h"
@@ -125,6 +126,7 @@ private:
         TEST_CASE(version);
         TEST_CASE(versionWithCfg);
         TEST_CASE(versionExclusive);
+        TEST_CASE(versionWithInvalidCfg);
         TEST_CASE(onefile);
         TEST_CASE(onepath);
         TEST_CASE(optionwithoutfile);
@@ -268,7 +270,9 @@ private:
         TEST_CASE(showtimeEmpty);
         TEST_CASE(showtimeInvalid);
         TEST_CASE(errorlist);
+        TEST_CASE(errorlistWithCfg);
         TEST_CASE(errorlistExclusive);
+        TEST_CASE(errorlistWithInvalidCfg);
         TEST_CASE(ignorepathsnopath);
 #if defined(USE_WINDOWS_SEH) || defined(USE_UNIX_SIGNAL_HANDLING)
         TEST_CASE(exceptionhandling);
@@ -360,6 +364,8 @@ private:
         TEST_CASE(cppcheckBuildDirExistent);
         TEST_CASE(cppcheckBuildDirNonExistent);
         TEST_CASE(cppcheckBuildDirEmpty);
+
+        TEST_CASE(invalidCppcheckCfg);
     }
 
     void nooptions() {
@@ -412,7 +418,7 @@ private:
 
     void versionWithCfg() {
         REDIRECT;
-        ScopedFile file("cppcheck.cfg",
+        ScopedFile file(Path::join(Path::getPathFromFilename(Path::getCurrentExecutablePath("")), "cppcheck.cfg"),
                         "{\n"
                         "\"productName\": \"The Product\""
                         "}\n");
@@ -433,6 +439,16 @@ private:
         ASSERT_EQUALS("", GET_REDIRECT_OUTPUT);
     }
 
+    void versionWithInvalidCfg() {
+        REDIRECT;
+        ScopedFile file(Path::join(Path::getPathFromFilename(Path::getCurrentExecutablePath("")), "cppcheck.cfg"),
+                        "{\n");
+        const char * const argv[] = {"cppcheck", "--version"};
+        ASSERT_EQUALS(CmdLineParser::Result::Fail, parser->parseFromArgs(2, argv));
+        ASSERT_EQUALS("cppcheck: error: could not load cppcheck.cfg - not a valid JSON - syntax error at line 1 near: \n", logger->str());
+        ASSERT_EQUALS("", GET_REDIRECT_OUTPUT);
+    }
+
     void onefile() {
         REDIRECT;
         const char * const argv[] = {"cppcheck", "file.cpp"};
@@ -1690,11 +1706,19 @@ private:
         const char * const argv[] = {"cppcheck", "--errorlist"};
         ASSERT_EQUALS(CmdLineParser::Result::Exit, parser->parseFromArgs(2, argv));
         ASSERT_EQUALS("", logger->str()); // empty since it is logged via ErrorLogger
-        ASSERT(startsWith(GET_REDIRECT_OUTPUT, "<?xml"));
+        ASSERT(startsWith(GET_REDIRECT_OUTPUT, ErrorMessage::getXMLHeader("")));
         ASSERT(endsWith(GET_REDIRECT_OUTPUT, "</results>\n"));
     }
 
-    // TODO: test --errorlist with product name
+    void errorlistWithCfg() {
+        REDIRECT;
+        ScopedFile file(Path::join(Path::getPathFromFilename(Path::getCurrentExecutablePath("")), "cppcheck.cfg"),
+                        R"({"productName": "The Product"}\n)");
+        const char * const argv[] = {"cppcheck", "--errorlist"};
+        ASSERT_EQUALS(CmdLineParser::Result::Exit, parser->parseFromArgs(2, argv));
+        ASSERT_EQUALS("", logger->str()); // empty since it is logged via ErrorLogger
+        ASSERT(startsWith(GET_REDIRECT_OUTPUT, ErrorMessage::getXMLHeader("The Product")));
+    }
 
     void errorlistExclusive() {
         REDIRECT;
@@ -1705,6 +1729,16 @@ private:
         ASSERT(endsWith(GET_REDIRECT_OUTPUT, "</results>\n"));
     }
 
+    void errorlistWithInvalidCfg() {
+        REDIRECT;
+        ScopedFile file(Path::join(Path::getPathFromFilename(Path::getCurrentExecutablePath("")), "cppcheck.cfg"),
+                        "{\n");
+        const char * const argv[] = {"cppcheck", "--errorlist"};
+        ASSERT_EQUALS(CmdLineParser::Result::Fail, parser->parseFromArgs(2, argv));
+        ASSERT_EQUALS("cppcheck: error: could not load cppcheck.cfg - not a valid JSON - syntax error at line 1 near: \n", logger->str());
+        ASSERT_EQUALS("", GET_REDIRECT_OUTPUT);
+    }
+
     void ignorepathsnopath() {
         REDIRECT;
         const char * const argv[] = {"cppcheck", "-i"};
@@ -2309,6 +2343,15 @@ private:
         ASSERT_EQUALS(CmdLineParser::Result::Fail, parser->parseFromArgs(2, argv));
         ASSERT_EQUALS("cppcheck: error: Directory '' specified by --cppcheck-build-dir argument has to be existent.\n", logger->str());
     }
+
+    void invalidCppcheckCfg() {
+        REDIRECT;
+        ScopedFile file(Path::join(Path::getPathFromFilename(Path::getCurrentExecutablePath("")), "cppcheck.cfg"),
+                        "{\n");
+        const char * const argv[] = {"cppcheck", "test.cpp"};
+        ASSERT_EQUALS(CmdLineParser::Result::Fail, parser->parseFromArgs(2, argv));
+        ASSERT_EQUALS("cppcheck: error: could not load cppcheck.cfg - not a valid JSON - syntax error at line 1 near: \n", logger->str());
+    }
 };
 
 REGISTER_TEST(TestCmdlineParser)

test/testsettings.cpp

@@ -20,6 +20,7 @@
 #include "errortypes.h"
 #include "settings.h"
 #include "fixture.h"
+#include "helpers.h"
 
 class TestSettings : public TestFixture {
 public:
@@ -28,6 +29,7 @@ public:
 private:
     void run() override {
         TEST_CASE(simpleEnableGroup);
+        TEST_CASE(loadCppcheckCfg);
     }
 
     void simpleEnableGroup() const {
@@ -85,6 +87,128 @@ private:
         ASSERT_EQUALS(false, group.isEnabled(Checks::missingInclude));
         ASSERT_EQUALS(false, group.isEnabled(Checks::internalCheck));
     }
+
+    void loadCppcheckCfg()
+    {
+        {
+            Settings s;
+            ASSERT_EQUALS("", s.loadCppcheckCfg());
+        }
+        {
+            Settings s;
+            ScopedFile file("cppcheck.cfg",
+                            "{}\n");
+            ASSERT_EQUALS("", s.loadCppcheckCfg());
+        }
+        {
+            Settings s;
+            ScopedFile file("cppcheck.cfg",
+                            "{\n");
+            ASSERT_EQUALS("not a valid JSON - syntax error at line 1 near: ", s.loadCppcheckCfg());
+        }
+        {
+            Settings s;
+            ScopedFile file("cppcheck.cfg",
+                            R"({"productName": ""}\n)");
+            ASSERT_EQUALS("", s.loadCppcheckCfg());
+            ASSERT_EQUALS("", s.cppcheckCfgProductName);
+        }
+        {
+            Settings s;
+            ScopedFile file("cppcheck.cfg",
+                            R"({"productName": "product"}\n)");
+            ASSERT_EQUALS("", s.loadCppcheckCfg());
+            ASSERT_EQUALS("product", s.cppcheckCfgProductName);
+        }
+        {
+            Settings s;
+            ScopedFile file("cppcheck.cfg",
+                            R"({"productName": 1}\n)");
+            ASSERT_EQUALS("'productName' is not a string", s.loadCppcheckCfg());
+        }
+        {
+            Settings s;
+            ScopedFile file("cppcheck.cfg",
+                            R"({"about": ""}\n)");
+            ASSERT_EQUALS("", s.loadCppcheckCfg());
+            ASSERT_EQUALS("", s.cppcheckCfgAbout);
+        }
+        {
+            Settings s;
+            ScopedFile file("cppcheck.cfg",
+                            R"({"about": "about"}\n)");
+            ASSERT_EQUALS("", s.loadCppcheckCfg());
+            ASSERT_EQUALS("about", s.cppcheckCfgAbout);
+        }
+        {
+            Settings s;
+            ScopedFile file("cppcheck.cfg",
+                            R"({"about": 1}\n)");
+            ASSERT_EQUALS("'about' is not a string", s.loadCppcheckCfg());
+        }
+        {
+            Settings s;
+            ScopedFile file("cppcheck.cfg",
+                            R"({"addons": []}\n)");
+            ASSERT_EQUALS("", s.loadCppcheckCfg());
+            ASSERT_EQUALS(0, s.addons.size());
+        }
+        {
+            Settings s;
+            ScopedFile file("cppcheck.cfg",
+                            R"({"addons": 1}\n)");
+            ASSERT_EQUALS("'addons' is not an array", s.loadCppcheckCfg());
+        }
+        {
+            Settings s;
+            ScopedFile file("cppcheck.cfg",
+                            R"({"addons": ["addon"]}\n)");
+            ASSERT_EQUALS("", s.loadCppcheckCfg());
+            ASSERT_EQUALS(1, s.addons.size());
+            ASSERT_EQUALS("addon", *s.addons.cbegin());
+        }
+        {
+            Settings s;
+            ScopedFile file("cppcheck.cfg",
+                            R"({"addons": [1]}\n)");
+            ASSERT_EQUALS("'addons' array entry is not a string", s.loadCppcheckCfg());
+        }
+        {
+            Settings s;
+            ScopedFile file("cppcheck.cfg",
+                            R"({"addons": []}\n)");
+            ASSERT_EQUALS("", s.loadCppcheckCfg());
+            ASSERT_EQUALS(0, s.addons.size());
+        }
+        {
+            Settings s;
+            ScopedFile file("cppcheck.cfg",
+                            R"({"suppressions": 1}\n)");
+            ASSERT_EQUALS("'suppressions' is not an array", s.loadCppcheckCfg());
+        }
+        {
+            Settings s;
+            ScopedFile file("cppcheck.cfg",
+                            R"({"suppressions": ["id"]}\n)");
+            ASSERT_EQUALS("", s.loadCppcheckCfg());
+            ASSERT_EQUALS(1, s.nomsg.getSuppressions().size());
+            ASSERT_EQUALS("id", s.nomsg.getSuppressions().cbegin()->errorId);
+        }
+        {
+            Settings s;
+            ScopedFile file("cppcheck.cfg",
+                            R"({"suppressions": [""]}\n)");
+            ASSERT_EQUALS("could not parse suppression '' - Failed to add suppression. No id.", s.loadCppcheckCfg());
+        }
+        {
+            Settings s;
+            ScopedFile file("cppcheck.cfg",
+                            R"({"suppressions": [1]}\n)");
+            ASSERT_EQUALS("'suppressions' array entry is not a string", s.loadCppcheckCfg());
+        }
+
+        // TODO: test with FILESDIR
+    }
 };
 
 REGISTER_TEST(TestSettings)