diff --git a/cli/cppcheckexecutorsig.cpp b/cli/cppcheckexecutorsig.cpp
index 102aae1d4..40a5b988e 100644
--- a/cli/cppcheckexecutorsig.cpp
+++ b/cli/cppcheckexecutorsig.cpp
@@ -120,7 +120,6 @@ static void CppcheckSignalHandler(int signo, siginfo_t * info, void * context)
 
     const Signalmap_t::const_iterator it=listofsignals.find(signo);
     const char * const signame = (it==listofsignals.end()) ? "unknown" : it->second.c_str();
-    bool printCallstack=true; // try to print a callstack?
     bool lowMem=false; // was low-memory condition detected? Be careful then! Avoid allocating much more memory then.
     bool unexpectedSignal=true; // unexpected indicates program failure
     bool terminate=true; // exit process/thread
@@ -241,7 +240,6 @@ static void CppcheckSignalHandler(int signo, siginfo_t * info, void * context)
         unexpectedSignal=false;     // legal usage: interrupt application via CTRL-C
         fputs("cppcheck received signal ", output);
         fputs(signame, output);
-        printCallstack=true;
         fputs(".\n", output);
         break;
     case SIGSEGV:
@@ -277,11 +275,9 @@ static void CppcheckSignalHandler(int signo, siginfo_t * info, void * context)
         fputs(".\n", output);
         break;
     }
-    if (printCallstack) {
 #ifdef USE_UNIX_BACKTRACE_SUPPORT
-        print_stacktrace(output, true, -1, lowMem);
+    print_stacktrace(output, true, -1, lowMem);
 #endif
-    }
     if (unexpectedSignal) {
         fputs("\nPlease report this to the cppcheck developers!\n", output);
     }
diff --git a/cli/processexecutor.cpp b/cli/processexecutor.cpp
index 1e3e87229..01b2a6614 100644
--- a/cli/processexecutor.cpp
+++ b/cli/processexecutor.cpp
@@ -71,7 +71,7 @@ ProcessExecutor::~ProcessExecutor()
 
 class PipeWriter : public ErrorLogger {
 public:
-    enum PipeSignal {REPORT_OUT='1',REPORT_ERROR='2', REPORT_VERIFICATION='4', CHILD_END='5'};
+    enum PipeSignal {REPORT_OUT='1',REPORT_ERROR='2', CHILD_END='5'};
 
     explicit PipeWriter(int pipe) : mWpipe(pipe) {}
 
diff --git a/gui/common.h b/gui/common.h
index 1d10117cf..e98d260e9 100644
--- a/gui/common.h
+++ b/gui/common.h
@@ -36,8 +36,6 @@
 #define SETTINGS_WINDOW_MAXIMIZED       "Window maximized"
 #define SETTINGS_WINDOW_WIDTH           "Window width"
 #define SETTINGS_WINDOW_HEIGHT          "Window height"
-#define SETTINGS_LOG_VIEW_WIDTH         "Log/View width"
-#define SETTINGS_LOG_VIEW_HEIGHT        "Log/View height"
 #define SETTINGS_MAINWND_SPLITTER_STATE "Mainwindow/Vertical splitter state"
 #define SETTINGS_CHECK_DIALOG_WIDTH     "Check dialog width"
 #define SETTINGS_CHECK_DIALOG_HEIGHT    "Check dialog height"
@@ -101,7 +99,6 @@
 #define SETTINGS_LAST_PROJECT_PATH      "Last project path"
 #define SETTINGS_LAST_RESULT_PATH       "Last result path"
 #define SETTINGS_LAST_SOURCE_PATH       "Last source path"
-#define SETTINGS_LAST_INCLUDE_PATH      "Last include path"
 #define SETTINGS_LAST_APP_PATH          "Last application path"
 
 #define SETTINGS_LAST_ANALYZE_FILES_FILTER  "Last analyze files filter"
diff --git a/gui/mainwindow.cpp b/gui/mainwindow.cpp
index 938abee31..7d73e0b3b 100644
--- a/gui/mainwindow.cpp
+++ b/gui/mainwindow.cpp
@@ -92,7 +92,6 @@
 #include <QVariant>
 #include <Qt>
 
-static const QString OnlineHelpURL("https://cppcheck.sourceforge.io/manual.html");
 static const QString compile_commands_json("compile_commands.json");
 
 static QString fromNativePath(const QString& p) {
diff --git a/gui/projectfile.h b/gui/projectfile.h
index 1f53cd593..7926faf2b 100644
--- a/gui/projectfile.h
+++ b/gui/projectfile.h
@@ -402,9 +402,11 @@ public:
     QStringList getCheckUnknownFunctionReturn() const {
         return mCheckUnknownFunctionReturn;
     }
-    void setCheckUnknownFunctionReturn(const QStringList &s) {
+    /*
+       void setCheckUnknownFunctionReturn(const QStringList &s) {
         mCheckUnknownFunctionReturn = s;
-    }
+       }
+     */
 
     /** Use Clang parser */
     bool clangParser;
diff --git a/gui/projectfiledialog.cpp b/gui/projectfiledialog.cpp
index 0fd18e512..47e6c3965 100644
--- a/gui/projectfiledialog.cpp
+++ b/gui/projectfiledialog.cpp
@@ -347,6 +347,7 @@ void ProjectFileDialog::loadFromProjectFile(const ProjectFile *projectFile)
     mUI->mComboBoxPlatform->setCurrentText(projectFile->getPlatform());
     setSuppressions(projectFile->getSuppressions());
 
+    // TODO
     // Human knowledge..
     /*
        mUI->mListUnknownFunctionReturn->clear();
diff --git a/gui/resultstree.h b/gui/resultstree.h
index 5af272ede..1e67dca97 100644
--- a/gui/resultstree.h
+++ b/gui/resultstree.h
@@ -346,14 +346,6 @@ protected:
      */
     void startApplication(QStandardItem *target, int application = -1);
 
-    /**
-     * @brief Helper function to copy filename/full path to the clipboard
-     *
-     * @param target Error tree item to open
-     * @param fullPath Are we copying full path or only filename?
-     */
-    void copyPathToClipboard(QStandardItem *target, bool fullPath);
-
     /**
      * @brief Helper function returning the filename/full path of the error tree item \a target.
      *
diff --git a/gui/translationhandler.cpp b/gui/translationhandler.cpp
index 375cf5e9f..eaa04cb3a 100644
--- a/gui/translationhandler.cpp
+++ b/gui/translationhandler.cpp
@@ -90,7 +90,7 @@ bool TranslationHandler::setLanguage(const QString &code)
         failure = true;
     } else {
         // Make sure there is a translator
-        if (!mTranslator && !failure)
+        if (!mTranslator)
             mTranslator = new QTranslator(this);
 
         //Load the new language
@@ -108,18 +108,19 @@ bool TranslationHandler::setLanguage(const QString &code)
         else
             translationFile = appPath + "/" + mTranslations[index].mFilename + ".qm";
 
-        if (!mTranslator->load(translationFile) && !failure) {
+        if (!mTranslator->load(translationFile)) {
+            failure = true;
             //If it failed, lets check if the default file exists
             if (!QFile::exists(translationFile)) {
                 error = QObject::tr("Language file %1 not found!");
                 error = error.arg(translationFile);
-                failure = true;
             }
-
-            //If file exists, there's something wrong with it
-            error = QObject::tr("Failed to load translation for language %1 from file %2");
-            error = error.arg(mTranslations[index].mName);
-            error = error.arg(translationFile);
+            else {
+                //If file exists, there's something wrong with it
+                error = QObject::tr("Failed to load translation for language %1 from file %2");
+                error = error.arg(mTranslations[index].mName);
+                error = error.arg(translationFile);
+            }
         }
     }
 
diff --git a/lib/checkother.cpp b/lib/checkother.cpp
index 188cab433..80bac3689 100644
--- a/lib/checkother.cpp
+++ b/lib/checkother.cpp
@@ -64,7 +64,6 @@ static const struct CWE CWE571(571U);   // Expression is Always True
 static const struct CWE CWE672(672U);   // Operation on a Resource after Expiration or Release
 static const struct CWE CWE628(628U);   // Function Call with Incorrectly Specified Arguments
 static const struct CWE CWE683(683U);   // Function Call With Incorrect Order of Arguments
-static const struct CWE CWE686(686U);   // Function Call With Incorrect Argument Type
 static const struct CWE CWE704(704U);   // Incorrect Type Conversion or Cast
 static const struct CWE CWE758(758U);   // Reliance on Undefined, Unspecified, or Implementation-Defined Behavior
 static const struct CWE CWE768(768U);   // Incorrect Short Circuit Evaluation
diff --git a/lib/checkstl.cpp b/lib/checkstl.cpp
index 481364053..30cf435e2 100644
--- a/lib/checkstl.cpp
+++ b/lib/checkstl.cpp
@@ -451,11 +451,6 @@ static std::string getContainerName(const Token *containerToken)
     return ret;
 }
 
-enum OperandPosition {
-    Left,
-    Right
-};
-
 static bool isVector(const Token* tok)
 {
     if (!tok)
diff --git a/lib/checkuninitvar.h b/lib/checkuninitvar.h
index c592d3fca..7eb5e554f 100644
--- a/lib/checkuninitvar.h
+++ b/lib/checkuninitvar.h
@@ -133,7 +133,6 @@ public:
 private:
     std::set<const Token*> mUninitDiags;
     Check::FileInfo* getFileInfo() const;
-    bool isUnsafeFunction(const Scope* scope, int argnr, const Token** tok) const;
 
     void getErrorMessages(ErrorLogger* errorLogger, const Settings* settings) const override
     {
diff --git a/lib/color.h b/lib/color.h
index 871272a62..97115ca62 100644
--- a/lib/color.h
+++ b/lib/color.h
@@ -32,11 +32,7 @@ enum class Color {
     FgGreen    = 32,
     FgBlue     = 34,
     FgMagenta  = 35,
-    FgDefault  = 39,
-    BgRed      = 41,
-    BgGreen    = 42,
-    BgBlue     = 44,
-    BgDefault  = 49
+    FgDefault  = 39
 };
 CPPCHECKLIB std::ostream& operator<<(std::ostream& os, const Color& c);
 
diff --git a/lib/cppcheck.h b/lib/cppcheck.h
index 46ab23ae0..b737118e1 100644
--- a/lib/cppcheck.h
+++ b/lib/cppcheck.h
@@ -121,10 +121,6 @@ public:
     void tooManyConfigsError(const std::string &file, const int numberOfConfigurations);
     void purgedConfigurationMessage(const std::string &file, const std::string& configuration);
 
-    void dontSimplify() {
-        mSimplify = false;
-    }
-
     /** Analyse whole program, run this after all TUs has been scanned.
      * This is deprecated and the plan is to remove this when
      * .analyzeinfo is good enough.
diff --git a/lib/forwardanalyzer.cpp b/lib/forwardanalyzer.cpp
index 325a36d21..73e98f015 100644
--- a/lib/forwardanalyzer.cpp
+++ b/lib/forwardanalyzer.cpp
@@ -49,7 +49,7 @@ struct OnExit {
 
 struct ForwardTraversal {
     enum class Progress { Continue, Break, Skip };
-    enum class Terminate { None, Bail, Escape, Modified, Inconclusive, Conditional };
+    enum class Terminate { None, Bail, Inconclusive };
     ForwardTraversal(const ValuePtr<Analyzer>& analyzer, const Settings& settings)
         : analyzer(analyzer), settings(settings), actions(Analyzer::Action::None), analyzeOnly(false), analyzeTerminate(false)
     {}
@@ -333,8 +333,6 @@ struct ForwardTraversal {
 
     enum class Status {
         None,
-        Escaped,
-        Modified,
         Inconclusive,
     };
 
diff --git a/lib/library.h b/lib/library.h
index 325077876..5fac8a733 100644
--- a/lib/library.h
+++ b/lib/library.h
@@ -254,7 +254,7 @@ public:
         };
         struct RangeItemRecordTypeItem {
             std::string name;
-            int templateParameter;
+            int templateParameter; // TODO: use this
         };
         std::string startPattern, startPattern2, endPattern, itEndPattern;
         std::map<std::string, Function> functions;
@@ -407,15 +407,6 @@ public:
         return arg ? arg->valid : emptyString;
     }
 
-    struct InvalidArgValue {
-        enum class Type {le, lt, eq, ge, gt, range} type;
-        std::string op1;
-        std::string op2;
-        bool isInt() const {
-            return MathLib::isInt(op1);
-        }
-    };
-
     const ArgumentChecks::IteratorInfo *getArgIteratorInfo(const Token *ftok, int argnr) const {
         const ArgumentChecks *arg = getarg(ftok, argnr);
         return arg && arg->iteratorInfo.it ? &arg->iteratorInfo : nullptr;
diff --git a/lib/preprocessor.h b/lib/preprocessor.h
index bea2b0d27..a64ebdfb5 100644
--- a/lib/preprocessor.h
+++ b/lib/preprocessor.h
@@ -80,8 +80,7 @@ public:
      * Include file types.
      */
     enum HeaderTypes {
-        NoHeader = 0,
-        UserHeader,
+        UserHeader = 1,
         SystemHeader
     };
 
@@ -169,10 +168,6 @@ public:
 
     static void getErrorMessages(ErrorLogger *errorLogger, const Settings *settings);
 
-    void setFile0(const std::string &f) {
-        mFile0 = f;
-    }
-
     /**
      * dump all directives present in source file
      */
diff --git a/lib/programmemory.h b/lib/programmemory.h
index a05c9bb2d..1820b1770 100644
--- a/lib/programmemory.h
+++ b/lib/programmemory.h
@@ -171,8 +171,6 @@ bool conditionIsTrue(const Token* condition, ProgramMemory pm, const Settings* s
  */
 ProgramMemory getProgramMemory(const Token* tok, const Token* expr, const ValueFlow::Value& value, const Settings* settings);
 
-ProgramMemory getProgramMemory(const Token *tok, const ProgramMemory::Map& vars);
-
 ValueFlow::Value evaluateLibraryFunction(const std::unordered_map<nonneg int, ValueFlow::Value>& args,
                                          const std::string& returnValue,
                                          const Settings* settings);
diff --git a/lib/reverseanalyzer.cpp b/lib/reverseanalyzer.cpp
index d17595668..af5942008 100644
--- a/lib/reverseanalyzer.cpp
+++ b/lib/reverseanalyzer.cpp
@@ -388,12 +388,6 @@ struct ReverseTraversal {
     }
 };
 
-void valueFlowGenericReverse(Token* start, const ValuePtr<Analyzer>& a, const Settings& settings)
-{
-    ReverseTraversal rt{a, settings};
-    rt.traverse(start);
-}
-
 void valueFlowGenericReverse(Token* start, const Token* end, const ValuePtr<Analyzer>& a, const Settings& settings)
 {
     ReverseTraversal rt{a, settings};
diff --git a/lib/reverseanalyzer.h b/lib/reverseanalyzer.h
index f42e0852a..db80d3ada 100644
--- a/lib/reverseanalyzer.h
+++ b/lib/reverseanalyzer.h
@@ -25,7 +25,6 @@ class Token;
 template<class T>
 class ValuePtr;
 
-void valueFlowGenericReverse(Token* start, const ValuePtr<Analyzer>& a, const Settings& settings);
 void valueFlowGenericReverse(Token* start, const Token* end, const ValuePtr<Analyzer>& a, const Settings& settings);
 
 #endif
diff --git a/lib/settings.h b/lib/settings.h
index b1ab699ef..8d3600163 100644
--- a/lib/settings.h
+++ b/lib/settings.h
@@ -61,12 +61,6 @@ public:
     void fill() {
         mFlags = 0xFFFFFFFF;
     }
-    void setEnabledAll(bool enabled) {
-        if (enabled)
-            fill();
-        else
-            clear();
-    }
     bool isEnabled(T flag) const {
         return (mFlags & (1U << (uint32_t)flag)) != 0;
     }
diff --git a/lib/symboldatabase.cpp b/lib/symboldatabase.cpp
index 24f9a464f..ca2f2fee0 100644
--- a/lib/symboldatabase.cpp
+++ b/lib/symboldatabase.cpp
@@ -4462,13 +4462,6 @@ Scope::Scope(const SymbolDatabase *check_, const Token *classDef_, const Scope *
         className = nameTok->str();
 }
 
-bool Scope::hasDefaultConstructor() const
-{
-    return numConstructors > 0 && std::any_of(functionList.begin(), functionList.end(), [](const Function& func) {
-        return func.type == Function::eConstructor && func.argCount() == 0;
-    });
-}
-
 AccessControl Scope::defaultAccess() const
 {
     switch (type) {
diff --git a/lib/symboldatabase.h b/lib/symboldatabase.h
index f9f67ce8b..e4ba6a6d5 100644
--- a/lib/symboldatabase.h
+++ b/lib/symboldatabase.h
@@ -1175,8 +1175,6 @@ public:
         functionMap.insert(make_pair(back->tokenDef->str(), back));
     }
 
-    bool hasDefaultConstructor() const;
-
     AccessControl defaultAccess() const;
 
     /**
diff --git a/lib/token.cpp b/lib/token.cpp
index 04376b6ac..bbd401dd7 100644
--- a/lib/token.cpp
+++ b/lib/token.cpp
@@ -2516,10 +2516,6 @@ Token* findTypeEnd(Token* tok)
     return tok;
 }
 
-const Token* findTypeEnd(const Token* tok) {
-    return findTypeEnd(const_cast<Token*>(tok));
-}
-
 Token* findLambdaEndScope(Token* tok)
 {
     if (!Token::simpleMatch(tok, "["))
diff --git a/lib/token.h b/lib/token.h
index 6b5536105..a0ee70413 100644
--- a/lib/token.h
+++ b/lib/token.h
@@ -1455,7 +1455,6 @@ public:
 };
 
 Token* findTypeEnd(Token* tok);
-const Token* findTypeEnd(const Token* tok);
 Token* findLambdaEndScope(Token* tok);
 const Token* findLambdaEndScope(const Token* tok);
 
diff --git a/lib/tokenize.h b/lib/tokenize.h
index 212302a9d..18e2c45b6 100644
--- a/lib/tokenize.h
+++ b/lib/tokenize.h
@@ -158,13 +158,6 @@ public:
     nonneg int sizeOfType(const std::string& type) const;
 
     void simplifyDebug();
-    /**
-     * Try to determine if function parameter is passed by value by looking
-     * at the function declaration.
-     * @param fpar token for function parameter in the function call
-     * @return true if the parameter is passed by value. if unsure, false is returned
-     */
-    bool isFunctionParameterPassedByValue(const Token *fpar) const;
 
     /** Simplify assignment where rhs is a block : "x=({123;});" => "{x=123;}" */
     void simplifyAssignmentBlock();
@@ -554,12 +547,6 @@ private:
      */
     void simplifyCPPAttribute();
 
-    /**
-     * Replace strlen(str)
-     * @return true if any replacement took place, false else
-     * */
-    bool simplifyStrlen();
-
     /**
      * Convert namespace aliases
      */
diff --git a/test/cfg/boost.cpp b/test/cfg/boost.cpp
index 25ef4ceeb..ee6f77dd8 100644
--- a/test/cfg/boost.cpp
+++ b/test/cfg/boost.cpp
@@ -39,7 +39,7 @@ void valid_code(boost::function<void(void)> &pf_print_hello)
     pf_print_hello = boost::bind(print_hello);
 }
 
-void ignoredReturnValue(char * buf)
+void ignoredReturnValue()
 {
     // cppcheck-suppress ignoredReturnValue
     boost::math::round(1.5);
diff --git a/test/helpers.h b/test/helpers.h
index a0ca4bba5..d3117fe55 100644
--- a/test/helpers.h
+++ b/test/helpers.h
@@ -55,22 +55,6 @@ public:
 };
 
 
-class SimpleSuppressor : public ErrorLogger {
-public:
-    SimpleSuppressor(Settings &settings, ErrorLogger *next)
-        : settings(settings), next(next) {}
-    void reportOut(const std::string &outmsg, Color /*c*/ = Color::Reset) override {
-        next->reportOut(outmsg);
-    }
-    void reportErr(const ErrorMessage &msg) override {
-        if (!msg.callStack.empty() && !settings.nomsg.isSuppressed(msg))
-            next->reportErr(msg);
-    }
-private:
-    Settings &settings;
-    ErrorLogger *next;
-};
-
 class ScopedFile {
 public:
     ScopedFile(std::string name, const std::string &content, std::string path = "");