diff --git a/lib/checkunusedvar.cpp b/lib/checkunusedvar.cpp
index 558f85660..6f46e7792 100644
--- a/lib/checkunusedvar.cpp
+++ b/lib/checkunusedvar.cpp
@@ -1127,7 +1127,7 @@ void CheckUnusedVar::checkFunctionVariableUsage()
                     if (!tok->valueType())
                         continue;
                     bool check = false;
-                    switch(tok->valueType()->type) {
+                    switch (tok->valueType()->type) {
                     case ValueType::Type::UNKNOWN_TYPE:
                     case ValueType::Type::NONSTD:
                     case ValueType::Type::RECORD:
diff --git a/lib/tokenize.cpp b/lib/tokenize.cpp
index 416e7650b..6216d6302 100644
--- a/lib/tokenize.cpp
+++ b/lib/tokenize.cpp
@@ -52,14 +52,14 @@ namespace {
         VarIdScopeInfo()
             :isExecutable(false), isStructInit(false), isEnum(false), startVarid(0) {
         }
-        VarIdScopeInfo(bool _isExecutable, bool _isStructInit, bool _isEnum, unsigned int _startVarid)
-            :isExecutable(_isExecutable), isStructInit(_isStructInit), isEnum(_isEnum), startVarid(_startVarid) {
+        VarIdScopeInfo(bool isExecutable, bool isStructInit, bool isEnum, nonneg int startVarid)
+            :isExecutable(isExecutable), isStructInit(isStructInit), isEnum(isEnum), startVarid(startVarid) {
         }
 
         const bool isExecutable;
         const bool isStructInit;
         const bool isEnum;
-        const unsigned int startVarid;
+        const nonneg int startVarid;
     };
 }
 
@@ -189,7 +189,7 @@ Tokenizer::~Tokenizer()
 // SizeOfType - gives the size of a type
 //---------------------------------------------------------------------------
 
-unsigned int Tokenizer::sizeOfType(const Token *type) const
+nonneg int Tokenizer::sizeOfType(const Token *type) const
 {
     if (!type || type->str().empty())
         return 0;
@@ -197,7 +197,7 @@ unsigned int Tokenizer::sizeOfType(const Token *type) const
     if (type->tokType() == Token::eString)
         return Token::getStrLength(type) + 1U;
 
-    const std::map<std::string, unsigned int>::const_iterator it = mTypeSize.find(type->str());
+    const std::map<std::string, int>::const_iterator it = mTypeSize.find(type->str());
     if (it == mTypeSize.end()) {
         const Library::PodType* podtype = mSettings->library.podtype(type->str());
         if (!podtype)
@@ -410,7 +410,7 @@ namespace {
     };
 }
 
-static Token *splitDefinitionFromTypedef(Token *tok, unsigned int *unnamedCount)
+static Token *splitDefinitionFromTypedef(Token *tok, nonneg int *unnamedCount)
 {
     Token *tok1;
     std::string name;
@@ -2415,7 +2415,7 @@ void Tokenizer::combineOperators()
         } else if (cpp && (c1 == 'p' || c1 == '_') &&
                    Token::Match(tok, "private|protected|public|__published : !!:")) {
             bool simplify = false;
-            unsigned int par = 0U;
+            int par = 0;
             for (const Token *prev = tok->previous(); prev; prev = prev->previous()) {
                 if (prev->str() == ")") {
                     ++par;
@@ -2687,7 +2687,7 @@ void Tokenizer::arraySize()
 
 static Token *skipTernaryOp(Token *tok)
 {
-    unsigned int colonLevel = 1;
+    int colonLevel = 1;
     while (nullptr != (tok = tok->next())) {
         if (tok->str() == "?") {
             ++colonLevel;
@@ -2730,7 +2730,7 @@ void Tokenizer::simplifyLabelsCaseDefault()
 {
     const bool cpp = isCPP();
     bool executablescope = false;
-    unsigned int indentLevel = 0;
+    int indentLevel = 0;
     for (Token *tok = list.front(); tok; tok = tok->next()) {
         // Simplify labels in the executable scope..
         Token *start = const_cast<Token *>(startOfExecutableScope(tok));
@@ -2847,14 +2847,14 @@ void Tokenizer::simplifyTemplates()
 //---------------------------------------------------------------------------
 
 
-static bool setVarIdParseDeclaration(const Token **tok, const std::map<std::string,unsigned int> &variableId, bool executableScope, bool cpp, bool c)
+static bool setVarIdParseDeclaration(const Token **tok, const std::map<std::string,int> &variableId, bool executableScope, bool cpp, bool c)
 {
     const Token *tok2 = *tok;
     if (!tok2->isName())
         return false;
 
-    unsigned int typeCount = 0;
-    unsigned int singleNameCount = 0;
+    int typeCount = 0;
+    int singleNameCount = 0;
     bool hasstruct = false;   // Is there a "struct" or "class"?
     bool bracket = false;
     bool ref = false;
@@ -2967,17 +2967,17 @@ static bool setVarIdParseDeclaration(const Token **tok, const std::map<std::stri
 
 
 void Tokenizer::setVarIdStructMembers(Token **tok1,
-                                      std::map<unsigned int, std::map<std::string, unsigned int> >& structMembers,
-                                      unsigned int *varId)
+                                      std::map<int, std::map<std::string, int> >& structMembers,
+                                      nonneg int *varId)
 {
     Token *tok = *tok1;
 
     if (Token::Match(tok, "%name% = { . %name% =")) {
-        const unsigned int struct_varid = tok->varId();
+        const int struct_varid = tok->varId();
         if (struct_varid == 0)
             return;
 
-        std::map<std::string, unsigned int>& members = structMembers[struct_varid];
+        std::map<std::string, int>& members = structMembers[struct_varid];
 
         tok = tok->tokAt(3);
         while (tok->str() != "}") {
@@ -2985,7 +2985,7 @@ void Tokenizer::setVarIdStructMembers(Token **tok1,
                 tok = tok->link();
             if (Token::Match(tok->previous(), "[,{] . %name% =")) {
                 tok = tok->next();
-                const std::map<std::string, unsigned int>::iterator it = members.find(tok->str());
+                const std::map<std::string, int>::iterator it = members.find(tok->str());
                 if (it == members.end()) {
                     members[tok->str()] = ++(*varId);
                     tok->varId(*varId);
@@ -3006,7 +3006,7 @@ void Tokenizer::setVarIdStructMembers(Token **tok1,
             tok = tok->tokAt(3);
             continue;
         }
-        const unsigned int struct_varid = tok->varId();
+        const int struct_varid = tok->varId();
         tok = tok->tokAt(2);
         if (struct_varid == 0)
             continue;
@@ -3018,8 +3018,8 @@ void Tokenizer::setVarIdStructMembers(Token **tok1,
         if (TemplateSimplifier::templateParameters(tok->next()) > 0)
             break;
 
-        std::map<std::string, unsigned int>& members = structMembers[struct_varid];
-        const std::map<std::string, unsigned int>::iterator it = members.find(tok->str());
+        std::map<std::string, int>& members = structMembers[struct_varid];
+        const std::map<std::string, int>::iterator it = members.find(tok->str());
         if (it == members.end()) {
             members[tok->str()] = ++(*varId);
             tok->varId(*varId);
@@ -3034,8 +3034,8 @@ void Tokenizer::setVarIdStructMembers(Token **tok1,
 
 void Tokenizer::setVarIdClassDeclaration(const Token * const startToken,
         const VariableMap &variableMap,
-        const unsigned int scopeStartVarId,
-        std::map<unsigned int, std::map<std::string,unsigned int> >& structMembers)
+        const nonneg int scopeStartVarId,
+        std::map<int, std::map<std::string,int> >& structMembers)
 {
     // end of scope
     const Token * const endToken = startToken->link();
@@ -3052,7 +3052,7 @@ void Tokenizer::setVarIdClassDeclaration(const Token * const startToken,
     }
 
     // replace varids..
-    unsigned int indentlevel = 0;
+    int indentlevel = 0;
     bool initList = false;
     bool inEnum = false;
     const Token *initListArgLastToken = nullptr;
@@ -3076,7 +3076,7 @@ void Tokenizer::setVarIdClassDeclaration(const Token * const startToken,
             --indentlevel;
             inEnum = false;
         } else if (initList && indentlevel == 0 && Token::Match(tok->previous(), "[,:] %name% [({]")) {
-            const std::map<std::string, unsigned int>::const_iterator it = variableMap.find(tok->str());
+            const std::map<std::string, int>::const_iterator it = variableMap.find(tok->str());
             if (it != variableMap.end()) {
                 tok->varId(it->second);
             }
@@ -3094,7 +3094,7 @@ void Tokenizer::setVarIdClassDeclaration(const Token * const startToken,
                 }
 
                 if (!inEnum) {
-                    const std::map<std::string, unsigned int>::const_iterator it = variableMap.find(tok->str());
+                    const std::map<std::string, int>::const_iterator it = variableMap.find(tok->str());
                     if (it != variableMap.end()) {
                         tok->varId(it->second);
                         setVarIdStructMembers(&tok, structMembers, variableMap.getVarId());
@@ -3113,9 +3113,9 @@ void Tokenizer::setVarIdClassDeclaration(const Token * const startToken,
 void Tokenizer::setVarIdClassFunction(const std::string &classname,
                                       Token * const startToken,
                                       const Token * const endToken,
-                                      const std::map<std::string, unsigned int> &varlist,
-                                      std::map<unsigned int, std::map<std::string, unsigned int> >& structMembers,
-                                      unsigned int *varId_)
+                                      const std::map<std::string, int> &varlist,
+                                      std::map<int, std::map<std::string, int> >& structMembers,
+                                      nonneg int *varId_)
 {
     for (Token *tok2 = startToken; tok2 && tok2 != endToken; tok2 = tok2->next()) {
         if (tok2->varId() != 0 || !tok2->isName())
@@ -3127,7 +3127,7 @@ void Tokenizer::setVarIdClassFunction(const std::string &classname,
         if (Token::Match(tok2->tokAt(-2), "!!this .") && !Token::simpleMatch(tok2->tokAt(-5), "( * this ) ."))
             continue;
 
-        const std::map<std::string,unsigned int>::const_iterator it = varlist.find(tok2->str());
+        const std::map<std::string,int>::const_iterator it = varlist.find(tok2->str());
         if (it != varlist.end()) {
             tok2->varId(it->second);
             setVarIdStructMembers(&tok2, structMembers, varId_);
@@ -3166,7 +3166,7 @@ void Tokenizer::setVarIdPass1()
     const std::set<std::string>& notstart = (isC()) ? notstart_c : notstart_cpp;
 
     VariableMap variableMap;
-    std::map<unsigned int, std::map<std::string, unsigned int> > structMembers;
+    std::map<int, std::map<std::string, int> > structMembers;
 
     std::stack<VarIdScopeInfo> scopeStack;
 
@@ -3359,7 +3359,7 @@ void Tokenizer::setVarIdPass1()
                         const Token *end = tok->findClosingBracket();
                         while (tok != end) {
                             if (tok->isName()) {
-                                const std::map<std::string, unsigned int>::const_iterator it = variableMap.find(tok->str());
+                                const std::map<std::string, int>::const_iterator it = variableMap.find(tok->str());
                                 if (it != variableMap.end())
                                     tok->varId(it->second);
                             }
@@ -3400,7 +3400,7 @@ void Tokenizer::setVarIdPass1()
                         if (!Token::Match(start, "[(,] %type% %name%|*|&"))
                             break;
                     }
-                    if (start->varId() > 0U)
+                    if (start->varId() > 0)
                         break;
                 }
 
@@ -3417,7 +3417,7 @@ void Tokenizer::setVarIdPass1()
             }
 
             if (!scopeStack.top().isEnum) {
-                const std::map<std::string, unsigned int>::const_iterator it = variableMap.find(tok->str());
+                const std::map<std::string, int>::const_iterator it = variableMap.find(tok->str());
                 if (it != variableMap.end()) {
                     tok->varId(it->second);
                     setVarIdStructMembers(&tok, structMembers, variableMap.getVarId());
@@ -3542,7 +3542,7 @@ static Token * matchMemberFunctionName(const Member &func, const std::list<Scope
 
 void Tokenizer::setVarIdPass2()
 {
-    std::map<unsigned int, std::map<std::string, unsigned int> > structMembers;
+    std::map<int, std::map<std::string, int> > structMembers;
 
     // Member functions and variables in this source
     std::list<Member> allMemberFunctions;
@@ -3604,7 +3604,7 @@ void Tokenizer::setVarIdPass2()
     std::list<ScopeInfo2> scopeInfo;
 
     // class members..
-    std::map<std::string, std::map<std::string, unsigned int> > varsByClass;
+    std::map<std::string, std::map<std::string, int> > varsByClass;
     for (Token *tok = list.front(); tok; tok = tok->next()) {
         while (tok->str() == "}" && !scopeInfo.empty() && tok == scopeInfo.back().bodyEnd)
             scopeInfo.pop_back();
@@ -3627,7 +3627,7 @@ void Tokenizer::setVarIdPass2()
         for (const Token *it : classnameTokens)
             classname += (classname.empty() ? "" : " :: ") + it->str();
 
-        std::map<std::string, unsigned int> &thisClassVars = varsByClass[scopeName2 + classname];
+        std::map<std::string, int> &thisClassVars = varsByClass[scopeName2 + classname];
         while (Token::Match(tokStart, ":|::|,|%name%")) {
             if (Token::Match(tokStart, "%name% <")) {
                 tokStart = tokStart->next()->findClosingBracket();
@@ -3636,7 +3636,7 @@ void Tokenizer::setVarIdPass2()
                 continue;
             }
             if (Token::Match(tokStart, "%name% ,|{")) {
-                const std::map<std::string, unsigned int>& baseClassVars = varsByClass[tokStart->str()];
+                const std::map<std::string, int>& baseClassVars = varsByClass[tokStart->str()];
                 thisClassVars.insert(baseClassVars.begin(), baseClassVars.end());
             }
             tokStart = tokStart->next();
@@ -3719,7 +3719,7 @@ void Tokenizer::setVarIdPass2()
                     break;
 
                 // set varid
-                const std::map<std::string, unsigned int>::const_iterator varpos = thisClassVars.find(tok3->str());
+                const std::map<std::string, int>::const_iterator varpos = thisClassVars.find(tok3->str());
                 if (varpos != thisClassVars.end())
                     tok3->varId(varpos->second);
 
@@ -3941,16 +3941,16 @@ void Tokenizer::sizeofAddParentheses()
 bool Tokenizer::simplifySizeof()
 {
     // Locate variable declarations and calculate the size
-    std::map<unsigned int, unsigned int> sizeOfVar;
-    std::map<unsigned int, const Token *> declTokOfVar;
+    std::map<int, int> sizeOfVar;
+    std::map<int, const Token *> declTokOfVar;
     for (const Token *tok = list.front(); tok; tok = tok->next()) {
         if (tok->varId() != 0 && sizeOfVar.find(tok->varId()) == sizeOfVar.end()) {
-            const unsigned int varId = tok->varId();
+            const int varId = tok->varId();
             if (Token::Match(tok->tokAt(-3), "[;{}(,] %type% * %name% [;,)]") ||
                 Token::Match(tok->tokAt(-4), "[;{}(,] const %type% * %name% [;),]") ||
                 Token::Match(tok->tokAt(-2), "[;{}(,] %type% %name% [;),]") ||
                 Token::Match(tok->tokAt(-3), "[;{}(,] const %type% %name% [;),]")) {
-                const unsigned int size = sizeOfType(tok->previous());
+                const int size = sizeOfType(tok->previous());
                 if (size == 0) {
                     continue;
                 }
@@ -3961,7 +3961,7 @@ bool Tokenizer::simplifySizeof()
 
             else if (Token::Match(tok->previous(), "%type% %name% [ %num% ] [[;=]") ||
                      Token::Match(tok->tokAt(-2), "%type% * %name% [ %num% ] [[;=]")) {
-                unsigned int size = sizeOfType(tok->previous());
+                int size = sizeOfType(tok->previous());
                 if (size == 0)
                     continue;
 
@@ -4039,7 +4039,7 @@ bool Tokenizer::simplifySizeof()
 
         // sizeof( a )
         else if (Token::Match(tok->next(), "( %var% )")) {
-            const std::map<unsigned int, unsigned int>::const_iterator sizeOfVarPos = sizeOfVar.find(tok->tokAt(2)->varId());
+            const std::map<int, int>::const_iterator sizeOfVarPos = sizeOfVar.find(tok->tokAt(2)->varId());
             if (sizeOfVarPos != sizeOfVar.end()) {
                 tok->deleteNext();
                 tok->deleteThis();
@@ -4053,7 +4053,7 @@ bool Tokenizer::simplifySizeof()
         }
 
         else if (Token::Match(tok->next(), "( %type% )")) {
-            const unsigned int size = sizeOfType(tok->tokAt(2));
+            const int size = sizeOfType(tok->tokAt(2));
             if (size > 0) {
                 tok->str(MathLib::toString(size));
                 tok->deleteNext(3);
@@ -4062,7 +4062,7 @@ bool Tokenizer::simplifySizeof()
         }
 
         else if (Token::simpleMatch(tok->next(), "( *") || Token::Match(tok->next(), "( %name% [")) {
-            unsigned int derefs = 0;
+            int derefs = 0;
 
             const Token* nametok = tok->tokAt(2);
             if (nametok->str() == "*") {
@@ -4087,7 +4087,7 @@ bool Tokenizer::simplifySizeof()
             // Some default value
             MathLib::biguint size = 0;
 
-            const unsigned int varid = nametok->varId();
+            const int varid = nametok->varId();
             if (derefs != 0 && varid != 0 && declTokOfVar.find(varid) != declTokOfVar.end()) {
                 // Try to locate variable declaration..
                 const Token *decltok = declTokOfVar[varid];
@@ -4099,7 +4099,7 @@ bool Tokenizer::simplifySizeof()
                 // Multi-dimensional array..
                 if (Token::Match(decltok, "%name% [") && Token::simpleMatch(decltok->linkAt(1), "] [")) {
                     const Token *tok2 = decltok;
-                    for (unsigned int i = 0; i < derefs; i++)
+                    for (int i = 0; i < derefs; i++)
                         tok2 = tok2->linkAt(1); // Skip all dimensions that are dereferenced before the sizeof call
                     while (Token::Match(tok2, "] [ %num% ]")) {
                         size *= MathLib::toULongNumber(tok2->strAt(2));
@@ -4681,7 +4681,7 @@ bool Tokenizer::simplifyTokenList2()
 }
 //---------------------------------------------------------------------------
 
-void Tokenizer::printDebugOutput(unsigned int simplification) const
+void Tokenizer::printDebugOutput(int simplification) const
 {
     const bool debug = (simplification != 1U && mSettings->debugSimplified) ||
                        (simplification != 2U && mSettings->debugnormal);
@@ -4774,7 +4774,7 @@ void Tokenizer::dump(std::ostream &out) const
         }
         if (tok->link())
             out << " link=\"" << tok->link() << '\"';
-        if (tok->varId() > 0U)
+        if (tok->varId() > 0)
             out << " varId=\"" << MathLib::toString(tok->varId()) << '\"';
         if (tok->variable())
             out << " variable=\"" << tok->variable() << '\"';
@@ -5051,7 +5051,7 @@ void Tokenizer::removeRedundantAssignment()
         if (start) {
             tok = start->previous();
             // parse in this function..
-            std::set<unsigned int> localvars;
+            std::set<int> localvars;
             const Token * const end = tok->next()->link();
             for (Token * tok2 = tok->next(); tok2 && tok2 != end; tok2 = tok2->next()) {
                 // skip local class or struct
@@ -5185,7 +5185,7 @@ void Tokenizer::simplifyFlowControl()
             continue;
 
         Token* end = begin->linkAt(1+(begin->next()->str() == "{" ? 0 : 1));
-        unsigned int indentLevel = 0;
+        int indentLevel = 0;
         bool stilldead = false;
 
         for (Token *tok = begin; tok && tok != end; tok = tok->next()) {
@@ -5325,7 +5325,7 @@ void Tokenizer::removeRedundantFor()
             if (type)
                 varTok = varTok->next();
             const std::string varname(varTok->str());
-            const unsigned int varid(varTok->varId());
+            const int varid(varTok->varId());
             if (varname != varTok->strAt(4))
                 continue;
             const Token *vartok2 = tok->linkAt(2)->previous();
@@ -5878,7 +5878,7 @@ bool Tokenizer::simplifyConstTernaryOp()
             // delete the condition token and the "?"
             tok->deleteNext(2);
 
-            unsigned int ternaryOplevel = 0;
+            int ternaryOplevel = 0;
             for (const Token *endTok = colon; endTok; endTok = endTok->next()) {
                 if (Token::Match(endTok, "(|[|{")) {
                     endTok = endTok->link();
@@ -5916,7 +5916,7 @@ void Tokenizer::simplifyUndefinedSizeArray()
 
             tok = tok2->previous();
             Token *end = tok2->next();
-            unsigned int count = 0;
+            int count = 0;
             do {
                 end = end->tokAt(2);
                 ++count;
@@ -5955,7 +5955,7 @@ void Tokenizer::simplifyCasts()
         // #4164 : ((unsigned char)1) => (1)
         if (Token::Match(tok->next(), "( %type% ) %num%") && tok->next()->link()->previous()->isStandardType()) {
             const MathLib::bigint value = MathLib::toLongNumber(tok->next()->link()->next()->str());
-            unsigned int bits = mSettings->char_bit * mTypeSize[tok->next()->link()->previous()->str()];
+            int bits = mSettings->char_bit * mTypeSize[tok->next()->link()->previous()->str()];
             if (!tok->tokAt(2)->isUnsigned() && bits > 0)
                 bits--;
             if (bits < 31 && value >= 0 && value < (1LL << bits)) {
@@ -6406,7 +6406,7 @@ void Tokenizer::simplifyVarDecl(Token * tokBegin, const Token * const tokEnd, co
         bool isconst = false;
         bool isstatic = false;
         Token *tok2 = type0;
-        unsigned int typelen = 1;
+        int typelen = 1;
 
         if (Token::Match(tok2, "::|extern")) {
             tok2 = tok2->next();
@@ -6469,8 +6469,8 @@ void Tokenizer::simplifyVarDecl(Token * tokBegin, const Token * const tokEnd, co
             tok2 = tok2->tokAt(2);
             if (tok2 && tok2->previous()->str() == "::")
                 continue;
-            unsigned int indentlevel = 0;
-            unsigned int parens = 0;
+            int indentlevel = 0;
+            int parens = 0;
 
             for (Token *tok3 = tok2; tok3; tok3 = tok3->next()) {
                 ++typelen;
@@ -6484,7 +6484,7 @@ void Tokenizer::simplifyVarDecl(Token * tokBegin, const Token * const tokEnd, co
                     }
                     --indentlevel;
                 } else if (!parens && tok3->str() == ">>") {
-                    if (indentlevel <= 1U) {
+                    if (indentlevel <= 1) {
                         tok2 = tok3->next();
                         break;
                     }
@@ -6781,7 +6781,7 @@ void Tokenizer::simplifyIfAndWhileAssign()
 
         // If it's a while loop, insert the assignment in the loop
         if (iswhile && !isDoWhile) {
-            unsigned int indentlevel = 0;
+            int indentlevel = 0;
             Token *tok3 = tok2;
 
             for (; tok3; tok3 = tok3->next()) {
@@ -6879,7 +6879,7 @@ static const std::map<std::string, std::string> cAlternativeTokens = {
 bool Tokenizer::simplifyCAlternativeTokens()
 {
     /* executable scope level */
-    unsigned int executableScopeLevel = 0;
+    int executableScopeLevel = 0;
 
     bool ret = false;
     for (Token *tok = list.front(); tok; tok = tok->next()) {
@@ -6947,7 +6947,7 @@ void Tokenizer::simplifyInitVar()
                 tok1 = tok1->next();
             tok1->str(";");
 
-            const unsigned int numTokens = (Token::Match(tok, "class|struct|union")) ? 2U : 1U;
+            const int numTokens = (Token::Match(tok, "class|struct|union")) ? 2U : 1U;
             list.insertTokens(tok1, tok, numTokens);
             tok = initVar(tok);
         }
@@ -7007,9 +7007,9 @@ bool Tokenizer::simplifyKnownVariables()
 
     // constants..
     {
-        std::unordered_map<unsigned int, std::string> constantValues;
-        std::map<unsigned int, Token*> constantVars;
-        std::unordered_map<unsigned int, std::list<Token*>> constantValueUsages;
+        std::unordered_map<int, std::string> constantValues;
+        std::map<int, Token*> constantVars;
+        std::unordered_map<int, std::list<Token*>> constantValueUsages;
         bool goback = false;
         for (Token *tok = list.front(); tok; tok = tok->next()) {
             if (goback) {
@@ -7121,9 +7121,9 @@ bool Tokenizer::simplifyKnownVariables()
     }
 
     // variable id for local, float/double, array variables
-    std::set<unsigned int> localvars;
-    std::set<unsigned int> floatvars;
-    std::set<unsigned int> arrays;
+    std::set<int> localvars;
+    std::set<int> floatvars;
+    std::set<int> arrays;
 
     // auto variables..
     for (Token *tok = list.front(); tok; tok = tok->next()) {
@@ -7178,7 +7178,7 @@ bool Tokenizer::simplifyKnownVariables()
                       Token::Match(tok2, "%name% [ %num%| ] = %str% ;") ||
                       Token::Match(tok2, "%name% = & %name% ;") ||
                       (Token::Match(tok2, "%name% = & %name% [ 0 ] ;") && arrays.find(tok2->tokAt(3)->varId()) != arrays.end()))) {
-                const unsigned int varid = tok2->varId();
+                const int varid = tok2->varId();
                 if (varid == 0)
                     continue;
 
@@ -7221,7 +7221,7 @@ bool Tokenizer::simplifyKnownVariables()
                 const Token * const valueToken = tok2->tokAt(2);
 
                 std::string value;
-                unsigned int valueVarId = 0;
+                int valueVarId = 0;
 
                 Token *tok3 = nullptr;
                 bool valueIsPointer = false;
@@ -7240,7 +7240,7 @@ bool Tokenizer::simplifyKnownVariables()
             }
 
             else if (Token::Match(tok2, "strcpy|sprintf ( %name% , %str% ) ;")) {
-                const unsigned int varid(tok2->tokAt(2)->varId());
+                const int varid(tok2->tokAt(2)->varId());
                 if (varid == 0)
                     continue;
 
@@ -7254,7 +7254,7 @@ bool Tokenizer::simplifyKnownVariables()
                         ++n;
                     }
                 }
-                const unsigned int valueVarId(0);
+                const int valueVarId(0);
                 const bool valueIsPointer(false);
                 Token *tok3 = tok2->tokAt(6);
                 ret |= simplifyKnownVariablesSimplify(&tok2, tok3, varid, emptyString, value, valueVarId, valueIsPointer, valueToken, indentlevel);
@@ -7272,7 +7272,7 @@ bool Tokenizer::simplifyKnownVariables()
     return ret;
 }
 
-bool Tokenizer::simplifyKnownVariablesGetData(unsigned int varid, Token **_tok2, Token **_tok3, std::string &value, unsigned int &valueVarId, bool &valueIsPointer, bool floatvar)
+bool Tokenizer::simplifyKnownVariablesGetData(nonneg int varid, Token **_tok2, Token **_tok3, std::string &value, nonneg int &valueVarId, bool &valueIsPointer, bool floatvar)
 {
     Token *tok2 = *_tok2;
     Token *tok3 = nullptr;
@@ -7341,7 +7341,7 @@ bool Tokenizer::simplifyKnownVariablesGetData(unsigned int varid, Token **_tok2,
     return true;
 }
 
-bool Tokenizer::simplifyKnownVariablesSimplify(Token **tok2, Token *tok3, unsigned int varid, const std::string &structname, std::string &value, unsigned int valueVarId, bool valueIsPointer, const Token * const valueToken, int indentlevel) const
+bool Tokenizer::simplifyKnownVariablesSimplify(Token **tok2, Token *tok3, nonneg int varid, const std::string &structname, std::string &value, nonneg int valueVarId, bool valueIsPointer, const Token * const valueToken, int indentlevel) const
 {
     const bool pointeralias(valueToken->isName() || Token::Match(valueToken, "& %name% ["));
     const bool varIsGlobal = (indentlevel == 0);
@@ -7587,7 +7587,7 @@ bool Tokenizer::simplifyKnownVariablesSimplify(Token **tok2, Token *tok3, unsign
                 // don't simplify buffer value
                 "memcmp","memcpy","memmove","memset","strcpy","strncmp","strncpy"
             };
-            for (unsigned int i = 0; i < (sizeof(functionName) / sizeof(*functionName)); ++i) {
+            for (int i = 0; i < (sizeof(functionName) / sizeof(*functionName)); ++i) {
                 if (valueVarId == 0U && i >= 2)
                     break;
                 if (tok3->str() == functionName[i]) {
@@ -7611,7 +7611,7 @@ bool Tokenizer::simplifyKnownVariablesSimplify(Token **tok2, Token *tok3, unsign
                 // don't simplify buffer value
                 "memcmp","memcpy","memmove"
             };
-            for (unsigned int i = 0; i < (sizeof(functionName) / sizeof(*functionName)); ++i) {
+            for (int i = 0; i < (sizeof(functionName) / sizeof(*functionName)); ++i) {
                 if (valueVarId == 0U && i >= 4)
                     break;
                 if (tok3->str() == functionName[i]) {
@@ -8033,7 +8033,7 @@ void Tokenizer::simplifyReference()
             for (Token *tok2 = tok; tok2 && tok2 != end; tok2 = tok2->next()) {
                 // found a reference..
                 if (Token::Match(tok2, "[;{}] %type% & %name% (|= %name% )| ;")) {
-                    const unsigned int refId = tok2->tokAt(3)->varId();
+                    const int refId = tok2->tokAt(3)->varId();
                     if (!refId)
                         continue;
 
@@ -8094,7 +8094,7 @@ void Tokenizer::simplifyOffsetPointerDereference()
 
 void Tokenizer::simplifyOffsetPointerReference()
 {
-    std::set<unsigned int> pod;
+    std::set<int> pod;
     for (const Token *tok = list.front(); tok; tok = tok->next()) {
         if (tok->isStandardType()) {
             tok = tok->next();
@@ -8326,7 +8326,7 @@ bool Tokenizer::isFunctionParameterPassedByValue(const Token *fpar) const
     const Token *ftok;
 
     // Look at function call, what parameter number is it?
-    unsigned int parameter = 1;
+    int parameter = 1;
     for (ftok = fpar->previous(); ftok; ftok = ftok->previous()) {
         if (ftok->str() == "(")
             break;
@@ -8352,7 +8352,7 @@ bool Tokenizer::isFunctionParameterPassedByValue(const Token *fpar) const
             else if (Token::Match(tok, "%type% (") && tok->str() == functionName) {
                 // Goto parameter
                 tok = tok->tokAt(2);
-                unsigned int par = 1;
+                int par = 1;
                 while (tok && par < parameter) {
                     if (tok->str() == ")")
                         break;
@@ -8390,13 +8390,13 @@ void Tokenizer::eraseDeadCode(Token *begin, const Token *end)
     if (!begin)
         return;
     const bool isgoto = Token::Match(begin->tokAt(-2), "goto %name% ;");
-    unsigned int indentlevel = 1,
-                 indentcase = 0,
-                 indentswitch = 0,
-                 indentlabel = 0,
-                 roundbraces = 0,
-                 indentcheck = 0;
-    std::vector<unsigned int> switchindents;
+    int indentlevel = 1;
+    int indentcase = 0;
+    int indentswitch = 0;
+    int indentlabel = 0;
+    int roundbraces = 0;
+    int indentcheck = 0;
+    std::vector<int> switchindents;
     bool checklabel = false;
     Token *tok = begin;
     Token *tokcheck = nullptr;
@@ -8517,7 +8517,7 @@ void Tokenizer::eraseDeadCode(Token *begin, const Token *end)
                     //instruction is removed, there's no sense to keep the
                     //case instructions. Remove them, if there are any.
                     Token *tok2 = tok->tokAt(3);
-                    unsigned int indentlevel2 = indentlevel;
+                    int indentlevel2 = indentlevel;
                     while (tok2->next() && tok2->next() != end) {
                         if (Token::Match(tok2->next(), "{|[|(")) {
                             tok2 = tok2->next()->link();
@@ -9077,7 +9077,7 @@ void Tokenizer::validate() const
         cppcheckError(lastTok);
 }
 
-static const Token *findUnmatchedTernaryOp(const Token * const begin, const Token * const end, unsigned depth = 0)
+static const Token *findUnmatchedTernaryOp(const Token * const begin, const Token * const end, int depth = 0)
 {
     std::stack<const Token *> ternaryOp;
     for (const Token *tok = begin; tok != end && tok->str() != ";"; tok = tok->next()) {
@@ -9207,7 +9207,7 @@ void Tokenizer::findGarbageCode() const
         if (!Token::simpleMatch(tok, "for (")) // find for loops
             continue;
         // count number of semicolons
-        unsigned int semicolons = 0;
+        int semicolons = 0;
         const Token* const startTok = tok;
         tok = tok->next()->link()->previous(); // find ")" of the for-loop
         // walk backwards until we find the beginning (startTok) of the for() again
@@ -9337,7 +9337,7 @@ std::string Tokenizer::simplifyString(const std::string &source)
             continue;
 
         int c = 'a';   // char
-        unsigned int sz = 0;    // size of stringdata
+        int sz = 0;    // size of stringdata
         if (str[i+1] == 'x') {
             sz = 2;
             while (sz < 4 && std::isxdigit((unsigned char)str[i+sz]))
@@ -9452,7 +9452,7 @@ void Tokenizer::simplifyErrNoInWhile()
 
 void Tokenizer::simplifyFuncInWhile()
 {
-    unsigned int count = 0;
+    int count = 0;
     for (Token *tok = list.front(); tok; tok = tok->next()) {
         if (!Token::Match(tok, "while ( %name% ( %name% ) ) {"))
             continue;
@@ -9461,7 +9461,7 @@ void Tokenizer::simplifyFuncInWhile()
         const Token * const var = tok->tokAt(4);
         Token * const end = tok->next()->link()->next()->link();
 
-        const unsigned int varid = ++mVarId; // Create new variable
+        const int varid = ++mVarId; // Create new variable
         const std::string varname("cppcheck:r" + MathLib::toString(++count));
         tok->str("int");
         tok->next()->insertToken(varname);
@@ -9492,7 +9492,7 @@ void Tokenizer::simplifyStructDecl()
     const bool cpp = isCPP();
 
     // A counter that is used when giving unique names for anonymous structs.
-    unsigned int count = 0;
+    int count = 0;
 
     // Skip simplification of unions in class definition
     std::stack<bool> skip; // true = in function, false = not in function
@@ -10002,7 +10002,7 @@ void Tokenizer::simplifyAssignmentBlock()
             const std::string &varname = tok->next()->str();
 
             // goto the "} )"
-            unsigned int indentlevel = 0;
+            int indentlevel = 0;
             Token *tok2 = tok;
             while (nullptr != (tok2 = tok2->next())) {
                 if (Token::Match(tok2, "(|{"))
@@ -10052,7 +10052,7 @@ void Tokenizer::simplifyAsm()
         else if (Token::Match(tok, "_asm|__asm")) {
             Token *endasm = tok->next();
             const Token *firstSemiColon = nullptr;
-            unsigned int comment = 0;
+            int comment = 0;
             while (Token::Match(endasm, "%num%|%name%|,|:|;") || (endasm && endasm->linenr() == comment)) {
                 if (Token::Match(endasm, "_asm|__asm|__endasm"))
                     break;
@@ -10097,7 +10097,7 @@ void Tokenizer::simplifyAsm()
         tok = tok->tokAt(2);
         if (tok->next() && tok->next()->str() == ";" &&
             tok->next()->linenr() != tok->linenr()) {
-            const unsigned int endposition = tok->next()->linenr();
+            const int endposition = tok->next()->linenr();
             tok = tok->tokAt(-3);
             for (int i = 0; i < 4; ++i) {
                 tok = tok->next();
@@ -10567,7 +10567,7 @@ void Tokenizer::simplifyQtSignalsSlots()
         }
 
         // count { and } for tok2
-        unsigned int indentlevel = 0;
+        int indentlevel = 0;
         for (Token *tok2 = tok; tok2; tok2 = tok2->next()) {
             if (tok2->str() == "{") {
                 ++indentlevel;
@@ -10850,7 +10850,7 @@ void Tokenizer::printUnknownTypes() const
 
     std::multimap<std::string, const Token *> unknowns;
 
-    for (unsigned int i = 1; i <= mVarId; ++i) {
+    for (int i = 1; i <= mVarId; ++i) {
         const Variable *var = mSymbolDatabase->getVariableFromVarId(i);
         if (!var)
             continue;
@@ -11033,7 +11033,7 @@ void Tokenizer::prepareTernaryOpForAST()
     for (Token* tok = list.front(); tok; tok = tok->next()) {
         if (tok->str() == "?") {
             bool parenthesesNeeded = false;
-            unsigned int depth = 0;
+            int depth = 0;
             Token* tok2 = tok->next();
             for (; tok2; tok2 = tok2->next()) {
                 if (tok2->link() && Token::Match(tok2, "[|(|<"))
@@ -11281,7 +11281,7 @@ Tokenizer::VariableMap::VariableMap() : mVarId(0) {}
 
 void Tokenizer::VariableMap::enterScope()
 {
-    mScopeInfo.push(std::list<std::pair<std::string, unsigned int>>());
+    mScopeInfo.push(std::list<std::pair<std::string, int>>());
 }
 
 bool Tokenizer::VariableMap::leaveScope()
@@ -11289,7 +11289,7 @@ bool Tokenizer::VariableMap::leaveScope()
     if (mScopeInfo.empty())
         return false;
 
-    for (const std::pair<std::string, unsigned int> &outerVariable : mScopeInfo.top()) {
+    for (const std::pair<std::string, int> &outerVariable : mScopeInfo.top()) {
         if (outerVariable.second != 0)
             mVariableId[outerVariable.first] = outerVariable.second;
         else
@@ -11305,13 +11305,13 @@ void Tokenizer::VariableMap::addVariable(const std::string &varname)
         mVariableId[varname] = ++mVarId;
         return;
     }
-    std::map<std::string, unsigned int>::iterator it = mVariableId.find(varname);
+    std::map<std::string, int>::iterator it = mVariableId.find(varname);
     if (it == mVariableId.end()) {
-        mScopeInfo.top().push_back(std::pair<std::string, unsigned int>(varname, 0));
+        mScopeInfo.top().push_back(std::pair<std::string, int>(varname, 0));
         mVariableId[varname] = ++mVarId;
         return;
     }
-    mScopeInfo.top().push_back(std::pair<std::string, unsigned int>(varname, it->second));
+    mScopeInfo.top().push_back(std::pair<std::string, int>(varname, it->second));
     it->second = ++mVarId;
 }
 
diff --git a/lib/tokenize.h b/lib/tokenize.h
index 9a263d14a..8f40960b5 100644
--- a/lib/tokenize.h
+++ b/lib/tokenize.h
@@ -58,25 +58,25 @@ class CPPCHECKLIB Tokenizer {
     /** Class used in Tokenizer::setVarIdPass1 */
     class VariableMap {
     private:
-        std::map<std::string, unsigned int> mVariableId;
-        std::stack<std::list<std::pair<std::string, unsigned int> > > mScopeInfo;
-        mutable unsigned int mVarId;
+        std::map<std::string, int> mVariableId;
+        std::stack<std::list<std::pair<std::string,int> > > mScopeInfo;
+        mutable nonneg int mVarId;
     public:
         VariableMap();
         void enterScope();
         bool leaveScope();
         void addVariable(const std::string &varname);
         bool hasVariable(const std::string &varname) const;
-        std::map<std::string, unsigned int>::const_iterator find(const std::string &varname) const {
+        std::map<std::string,int>::const_iterator find(const std::string &varname) const {
             return mVariableId.find(varname);
         }
-        std::map<std::string, unsigned int>::const_iterator end() const {
+        std::map<std::string,int>::const_iterator end() const {
             return mVariableId.end();
         }
-        const std::map<std::string, unsigned int> &map() const {
+        const std::map<std::string,int> &map() const {
             return mVariableId;
         }
-        unsigned int *getVarId() const {
+        nonneg int *getVarId() const {
             return &mVarId;
         }
     };
@@ -199,7 +199,7 @@ public:
      * @param type Token which will contain e.g. "int", "*", or string.
      * @return sizeof for given type, or 0 if it can't be calculated.
      */
-    unsigned int sizeOfType(const Token *type) const;
+    nonneg int sizeOfType(const Token *type) const;
 
     /**
      * Try to determine if function parameter is passed by value by looking
@@ -403,13 +403,13 @@ public:
      * Utility function for simplifyKnownVariables. Get data about an
      * assigned variable.
      */
-    static bool simplifyKnownVariablesGetData(unsigned int varid, Token **_tok2, Token **_tok3, std::string &value, unsigned int &valueVarId, bool &valueIsPointer, bool floatvar);
+    static bool simplifyKnownVariablesGetData(nonneg int varid, Token **_tok2, Token **_tok3, std::string &value, nonneg int &valueVarId, bool &valueIsPointer, bool floatvar);
 
     /**
      * utility function for simplifyKnownVariables. Perform simplification
      * of a given variable
      */
-    bool simplifyKnownVariablesSimplify(Token **tok2, Token *tok3, unsigned int varid, const std::string &structname, std::string &value, unsigned int valueVarId, bool valueIsPointer, const Token * const valueToken, int indentlevel) const;
+    bool simplifyKnownVariablesSimplify(Token **tok2, Token *tok3, nonneg int varid, const std::string &structname, std::string &value, nonneg int valueVarId, bool valueIsPointer, const Token * const valueToken, int indentlevel) const;
 
     /** Simplify useless C++ empty namespaces, like: 'namespace %name% { }'*/
     void simplifyEmptyNamespaces();
@@ -765,19 +765,19 @@ private:
 
     void setVarIdClassDeclaration(const Token * const startToken,
                                   const VariableMap &variableMap,
-                                  const unsigned int scopeStartVarId,
-                                  std::map<unsigned int, std::map<std::string,unsigned int> >& structMembers);
+                                  const nonneg int scopeStartVarId,
+                                  std::map<int, std::map<std::string,int> >& structMembers);
 
     void setVarIdStructMembers(Token **tok1,
-                               std::map<unsigned int, std::map<std::string, unsigned int> >& structMembers,
-                               unsigned int *varId);
+                               std::map<int, std::map<std::string, int> >& structMembers,
+                               nonneg int *varId);
 
     void setVarIdClassFunction(const std::string &classname,
                                Token * const startToken,
                                const Token * const endToken,
-                               const std::map<std::string, unsigned int> &varlist,
-                               std::map<unsigned int, std::map<std::string, unsigned int> >& structMembers,
-                               unsigned int *varId_);
+                               const std::map<std::string,int> &varlist,
+                               std::map<int, std::map<std::string,int> >& structMembers,
+                               nonneg int *varId_);
 
     /**
      * Simplify e.g. 'return(strncat(temp,"a",1));' into
@@ -817,7 +817,7 @@ public:
      * 1=1st simplifications
      * 2=2nd simplifications
      */
-    void printDebugOutput(unsigned int simplification) const;
+    void printDebugOutput(int simplification) const;
 
     void dump(std::ostream &out) const;
 
@@ -827,7 +827,7 @@ public:
      * Get variable count.
      * @return number of variables
      */
-    unsigned int varIdCount() const {
+    nonneg int varIdCount() const {
         return mVarId;
     }
 
@@ -895,7 +895,7 @@ private:
     * Get new variable id.
     * @return new variable id
     */
-    unsigned int newVarId() {
+    nonneg int newVarId() {
         return ++mVarId;
     }
 
@@ -918,13 +918,13 @@ private:
     std::string mConfiguration;
 
     /** sizeof information for known types */
-    std::map<std::string, unsigned int> mTypeSize;
+    std::map<std::string, int> mTypeSize;
 
     /** variable count */
-    unsigned int mVarId;
+    nonneg int mVarId;
 
     /** unnamed count "Unnamed0", "Unnamed1", "Unnamed2", ... */
-    unsigned int mUnnamedCount;
+    nonneg int mUnnamedCount;
 
     /**
      * was there any templates? templates that are "unused" are