fixed and enabled several clang-tidy warnings (#2816)

Author: firewave

.clang-tidy

@@ -1,5 +1,5 @@
 ---
-Checks:          '*,-abseil-*,-android-*,-cert-*,-cppcoreguidelines-*,-fuchsia-*,-google-*,-hicpp-*,-llvm-*,-linuxkernel-*,-mpi-*,-objc-*,-openmp-*,-zircon-*,-readability-braces-around-statements,-readability-magic-numbers,-bugprone-macro-parentheses,-readability-isolate-declaration,-readability-function-size,-modernize-use-trailing-return-type,-readability-implicit-bool-conversion,-readability-uppercase-literal-suffix,-modernize-use-auto,-readability-else-after-return,-modernize-use-default-member-init,-readability-named-parameter,-readability-redundant-member-init,-performance-faster-string-find,-modernize-avoid-c-arrays,-modernize-use-equals-default,-modernize-use-using,-readability-container-size-empty,-readability-simplify-boolean-expr,-modernize-use-override,-modernize-pass-by-value,-bugprone-branch-clone,-bugprone-narrowing-conversions,-modernize-raw-string-literal,-readability-convert-member-functions-to-static,-modernize-loop-convert,-misc-unused-using-decls,-modernize-use-emplace,-readability-const-return-type,-performance-unnecessary-value-param,-readability-static-accessed-through-instance,-modernize-return-braced-init-list,-performance-inefficient-string-concatenation,-performance-for-range-copy,-misc-throw-by-value-catch-by-reference,-modernize-use-bool-literals,-readability-avoid-const-params-in-decls,-readability-redundant-control-flow,-bugprone-argument-comment,-readability-redundant-string-cstr,-readability-non-const-parameter,-misc-non-private-member-variables-in-classes,-performance-unnecessary-copy-initialization,-readability-redundant-string-init,-bugprone-suspicious-string-compare,-bugprone-use-after-move,-readability-misleading-indentation,-misc-unused-parameters-,-clang-analyzer-*,-bugprone-signed-char-misuse,-readability-make-member-function-const,-llvmlibc-*'
+Checks:          '*,-abseil-*,-android-*,-cert-*,-cppcoreguidelines-*,-fuchsia-*,-google-*,-hicpp-*,-llvm-*,-llvmlibc-*,-linuxkernel-*,-mpi-*,-objc-*,-openmp-*,-zircon-*,-readability-braces-around-statements,-readability-magic-numbers,-bugprone-macro-parentheses,-readability-isolate-declaration,-readability-function-size,-modernize-use-trailing-return-type,-readability-implicit-bool-conversion,-readability-uppercase-literal-suffix,-modernize-use-auto,-readability-else-after-return,-modernize-use-default-member-init,-readability-named-parameter,-readability-redundant-member-init,-performance-faster-string-find,-modernize-avoid-c-arrays,-modernize-use-equals-default,-modernize-use-using,-readability-container-size-empty,-readability-simplify-boolean-expr,-modernize-use-override,-modernize-pass-by-value,-bugprone-branch-clone,-bugprone-narrowing-conversions,-modernize-raw-string-literal,-readability-convert-member-functions-to-static,-modernize-loop-convert,-misc-unused-using-decls,-modernize-use-emplace,-readability-const-return-type,-performance-unnecessary-value-param,-modernize-return-braced-init-list,-performance-inefficient-string-concatenation,-performance-for-range-copy,-misc-throw-by-value-catch-by-reference,-readability-avoid-const-params-in-decls,-readability-redundant-control-flow,-bugprone-argument-comment,-readability-non-const-parameter,-misc-non-private-member-variables-in-classes,-bugprone-suspicious-string-compare,-bugprone-use-after-move,-readability-misleading-indentation,-misc-unused-parameters-,-clang-analyzer-*,-bugprone-signed-char-misuse,-readability-make-member-function-const,-readability-inconsistent-declaration-parameter-name'
 CheckOptions:
   - key:             misc-non-private-member-variables-in-classes.IgnoreClassesWithAllMemberVariablesBeingPublic
     value:           '1'

cli/threadexecutor.cpp

@@ -355,7 +355,7 @@ void ThreadExecutor::reportInfo(const ErrorMessage &msg)
 
 void ThreadExecutor::bughuntingReport(const std::string &str)
 {
-    writeToPipe(REPORT_VERIFICATION, str.c_str());
+    writeToPipe(REPORT_VERIFICATION, str);
 }
 
 void ThreadExecutor::reportInternalChildErr(const std::string &childname, const std::string &msg)

gui/main.cpp

@@ -73,17 +73,17 @@ int main(int argc, char *argv[])
     TranslationHandler* th = new TranslationHandler(&app);
     th->setLanguage(settings->value(SETTINGS_LANGUAGE, th->suggestLanguage()).toString());
 
-    if (!CheckArgs(app.arguments()))
+    if (!CheckArgs(QApplication::arguments()))
         return 0;
 
-    app.setWindowIcon(QIcon(":cppcheck-gui.png"));
+    QApplication::setWindowIcon(QIcon(":cppcheck-gui.png"));
 
     // Register this metatype that is used to transfer error info
     qRegisterMetaType<ErrorItem>("ErrorItem");
 
     MainWindow window(th, settings);
     window.show();
-    return app.exec();
+    return QApplication::exec();
 }
 
 // Check only arguments needing action before GUI is shown.

gui/mainwindow.cpp

@@ -1000,7 +1000,7 @@ Settings MainWindow::getCppcheckSettings()
         result.jobs = 1;
     }
 
-    result.terminate(false);
+    Settings::terminate(false);
 
     return result;
 }

lib/checkcondition.cpp

@@ -1104,7 +1104,7 @@ void CheckCondition::checkIncorrectLogicOperator()
                     const std::string cond2 = expr1;
 
                     const std::string cond1VerboseMsg = expr1VerboseMsg + " " + tok->str() + " " + expr2VerboseMsg + " " + tok->astOperand2()->str() + " " + expr3VerboseMsg;
-                    const std::string cond2VerboseMsg = expr1VerboseMsg;
+                    const std::string& cond2VerboseMsg = expr1VerboseMsg;
                     // for the --verbose message, transform the actual condition and print it
                     const std::string msg = tok2->expressionString() + ". '" + cond1 + "' is equivalent to '" + cond2 + "'\n"
                                             "The condition '" + cond1VerboseMsg + "' is equivalent to '" + cond2VerboseMsg + "'.";

lib/cppcheck.cpp

@@ -88,7 +88,7 @@ namespace {
         }
 
         std::string parseAddonInfo(const picojson::value &json, const std::string &fileName, const std::string &exename) {
-            std::string json_error = picojson::get_last_error();
+            const std::string& json_error = picojson::get_last_error();
             if (!json_error.empty()) {
                 return "Loading " + fileName + " failed. " + json_error;
             }
@@ -1434,7 +1434,7 @@ void CppCheck::getErrorMessages()
 
 void CppCheck::analyseClangTidy(const ImportProject::FileSettings &fileSettings)
 {
-    std::string allIncludes = "";
+    std::string allIncludes;
     for (const std::string &inc : fileSettings.includePaths) {
         allIncludes = allIncludes + "-I\"" + inc + "\" ";
     }

lib/exprengine.cpp

@@ -2388,13 +2388,13 @@ static ExprEngine::ValuePtr executeNumber(const Token *tok, Data &data)
 
 static ExprEngine::ValuePtr executeStringLiteral(const Token *tok, Data &data)
 {
-    std::string s = tok->str();
+    const std::string& s = tok->str();
     return std::make_shared<ExprEngine::StringLiteralValue>(data.getNewSymbolName(), s.substr(1, s.size()-2));
 }
 
 static ExprEngine::ValuePtr executeExpression1(const Token *tok, Data &data)
 {
-    if (data.settings->terminated())
+    if (Settings::terminated())
         throw TerminateExpression();
 
     if (tok->str() == "return")

lib/symboldatabase.cpp

@@ -5583,7 +5583,7 @@ void SymbolDatabase::setValueType(Token *tok, const ValueType &valuetype)
         const Token *op1 = parent->astOperand2()->astOperand1();
         while (op1 && op1->str() == "[")
             op1 = op1->astOperand1();
-        ValueType vt(valuetype);
+        const ValueType& vt(valuetype);
         if (op1 && op1->variable() && op1->variable()->nameToken() == op1) {
             setValueType(parent, vt);
             return;

lib/templatesimplifier.cpp

@@ -1509,7 +1509,7 @@ void TemplateSimplifier::addNamespace(const TokenAndName &templateDeclaration, c
 
 bool TemplateSimplifier::alreadyHasNamespace(const TokenAndName &templateDeclaration, const Token *tok)
 {
-    std::string scope = templateDeclaration.scope();
+    const std::string& scope = templateDeclaration.scope();
 
     // get the length in tokens of the namespace
     std::string::size_type pos = 0;

lib/tokenize.cpp

@@ -5170,7 +5170,7 @@ void Tokenizer::simplifyHeadersAndUnusedTemplates()
         if (!tok->previous() || Token::Match(tok->previous(), "[;{}]")) {
             // Remove unused function declarations
             if (isIncluded && removeUnusedIncludedFunctions) {
-                while (1) {
+                while (true) {
                     Token *start = tok;
                     while (start && functionStart.find(start->str()) != functionStart.end())
                         start = start->next();
@@ -9856,7 +9856,7 @@ void Tokenizer::findGarbageCode() const
                 syntaxError(tok);
         }
         if (Token::Match(tok, "%or%|%oror%|~|^|!|%comp%|+|-|/|%")) {
-            std::string code = "";
+            std::string code;
             if (Token::Match(tok->next(), ")|]|}"))
                 code = tok->str() + tok->next()->str();
             if (Token::simpleMatch(tok->next(), "( )"))