diff --git a/lib/token.cpp b/lib/token.cpp
index c21d8ee8c..3e856b7a9 100644
--- a/lib/token.cpp
+++ b/lib/token.cpp
@@ -381,7 +381,7 @@ const std::string &Token::strAt(int index) const
     return tok ? tok->mStr : emptyString;
 }
 
-static int multiComparePercent(const Token *tok, const char*& haystack, unsigned int varid)
+static int multiComparePercent(const Token *tok, const char*& haystack, int varid)
 {
     ++haystack;
     // Compare only the first character of the string for optimization reasons
@@ -521,7 +521,7 @@ static int multiComparePercent(const Token *tok, const char*& haystack, unsigned
     return 0xFFFF;
 }
 
-int Token::multiCompare(const Token *tok, const char *haystack, unsigned int varid)
+int Token::multiCompare(const Token *tok, const char *haystack, int varid)
 {
     const char *needle = tok->str().c_str();
     const char *needlePointer = needle;
@@ -626,7 +626,7 @@ const char *Token::chrInFirstWord(const char *str, char c)
     }
 }
 
-bool Token::Match(const Token *tok, const char pattern[], unsigned int varid)
+bool Token::Match(const Token *tok, const char pattern[], int varid)
 {
     const char *p = pattern;
     while (*p) {
@@ -655,7 +655,7 @@ bool Token::Match(const Token *tok, const char pattern[], unsigned int varid)
 
             const char *temp = p+1;
             bool chrFound = false;
-            unsigned int count = 0;
+            int count = 0;
             while (*temp && *temp != ' ') {
                 if (*temp == ']') {
                     ++count;
@@ -713,12 +713,12 @@ bool Token::Match(const Token *tok, const char pattern[], unsigned int varid)
     return true;
 }
 
-std::size_t Token::getStrLength(const Token *tok)
+int Token::getStrLength(const Token *tok)
 {
     assert(tok != nullptr);
     assert(tok->mTokType == eString);
 
-    std::size_t len = 0;
+    int len = 0;
     std::string::const_iterator it = tok->str().begin() + 1U;
     const std::string::const_iterator end = tok->str().end() - 1U;
 
@@ -741,13 +741,13 @@ std::size_t Token::getStrLength(const Token *tok)
     return len;
 }
 
-std::size_t Token::getStrSize(const Token *tok)
+int Token::getStrSize(const Token *tok)
 {
     assert(tok != nullptr);
     assert(tok->tokType() == eString);
     const std::string &str = tok->str();
-    unsigned int sizeofstring = 1U;
-    for (unsigned int i = 1U; i < str.size() - 1U; i++) {
+    int sizeofstring = 1;
+    for (int i = 1; i < (int)str.size() - 1; i++) {
         if (str[i] == '\\')
             ++i;
         ++sizeofstring;
@@ -755,7 +755,7 @@ std::size_t Token::getStrSize(const Token *tok)
     return sizeofstring;
 }
 
-std::string Token::getCharAt(const Token *tok, std::size_t index)
+std::string Token::getCharAt(const Token *tok, MathLib::bigint index)
 {
     assert(tok != nullptr);
 
@@ -937,7 +937,7 @@ const Token *Token::findsimplematch(const Token * const startTok, const char pat
     return nullptr;
 }
 
-const Token *Token::findmatch(const Token * const startTok, const char pattern[], const unsigned int varId)
+const Token *Token::findmatch(const Token * const startTok, const char pattern[], const int varId)
 {
     for (const Token* tok = startTok; tok; tok = tok->next()) {
         if (Token::Match(tok, pattern, varId))
@@ -946,7 +946,7 @@ const Token *Token::findmatch(const Token * const startTok, const char pattern[]
     return nullptr;
 }
 
-const Token *Token::findmatch(const Token * const startTok, const char pattern[], const Token * const end, const unsigned int varId)
+const Token *Token::findmatch(const Token * const startTok, const char pattern[], const Token * const end, const int varId)
 {
     for (const Token* tok = startTok; tok && tok != end; tok = tok->next()) {
         if (Token::Match(tok, pattern, varId))
@@ -1333,7 +1333,7 @@ std::string Token::expressionString() const
     return stringFromTokenRange(tokens.first, tokens.second);
 }
 
-static void astStringXml(const Token *tok, std::size_t indent, std::ostream &out)
+static void astStringXml(const Token *tok, int indent, std::ostream &out)
 {
     const std::string strindent(indent, ' ');
 
@@ -1387,15 +1387,15 @@ void Token::printAst(bool verbose, bool xml, std::ostream &out) const
     }
 }
 
-static void indent(std::string &str, const unsigned int indent1, const unsigned int indent2)
+static void indent(std::string &str, const int indent1, const int indent2)
 {
-    for (unsigned int i = 0; i < indent1; ++i)
+    for (int i = 0; i < indent1; ++i)
         str += ' ';
-    for (unsigned int i = indent1; i < indent2; i += 2)
+    for (int i = indent1; i < indent2; i += 2)
         str += "| ";
 }
 
-void Token::astStringVerboseRecursive(std::string& ret, const unsigned int indent1, const unsigned int indent2) const
+void Token::astStringVerboseRecursive(std::string& ret, const int indent1, const int indent2) const
 {
     if (isExpandedMacro())
         ret += '$';
@@ -1405,7 +1405,7 @@ void Token::astStringVerboseRecursive(std::string& ret, const unsigned int inden
     ret += '\n';
 
     if (mImpl->mAstOperand1) {
-        unsigned int i1 = indent1, i2 = indent2 + 2;
+        int i1 = indent1, i2 = indent2 + 2;
         if (indent1 == indent2 && !mImpl->mAstOperand2)
             i1 += 2;
         indent(ret, indent1, indent2);
@@ -1413,7 +1413,7 @@ void Token::astStringVerboseRecursive(std::string& ret, const unsigned int inden
         mImpl->mAstOperand1->astStringVerboseRecursive(ret, i1, i2);
     }
     if (mImpl->mAstOperand2) {
-        unsigned int i1 = indent1, i2 = indent2 + 2;
+        int i1 = indent1, i2 = indent2 + 2;
         if (indent1 == indent2)
             i1 += 2;
         indent(ret, indent1, indent2);
@@ -1432,7 +1432,7 @@ std::string Token::astStringVerbose() const
 
 void Token::printValueFlow(bool xml, std::ostream &out) const
 {
-    unsigned int line = 0;
+    int line = 0;
     if (xml)
         out << "  <valueflow>" << std::endl;
     else
@@ -1582,7 +1582,7 @@ const ValueFlow::Value * Token::getValueGE(const MathLib::bigint val, const Sett
     return ret;
 }
 
-const ValueFlow::Value * Token::getInvalidValue(const Token *ftok, unsigned int argnr, const Settings *settings) const
+const ValueFlow::Value * Token::getInvalidValue(const Token *ftok, int argnr, const Settings *settings) const
 {
     if (!mImpl->mValues || !settings)
         return nullptr;
@@ -1611,11 +1611,11 @@ const Token *Token::getValueTokenMinStrSize() const
     if (!mImpl->mValues)
         return nullptr;
     const Token *ret = nullptr;
-    std::size_t minsize = ~0U;
+    int minsize = INT_MAX;
     std::list<ValueFlow::Value>::const_iterator it;
     for (it = mImpl->mValues->begin(); it != mImpl->mValues->end(); ++it) {
         if (it->isTokValue() && it->tokvalue && it->tokvalue->tokType() == Token::eString) {
-            const std::size_t size = getStrSize(it->tokvalue);
+            const int size = getStrSize(it->tokvalue);
             if (!ret || size < minsize) {
                 minsize = size;
                 ret = it->tokvalue;
@@ -1630,11 +1630,11 @@ const Token *Token::getValueTokenMaxStrLength() const
     if (!mImpl->mValues)
         return nullptr;
     const Token *ret = nullptr;
-    std::size_t maxlength = 0U;
+    int maxlength = 0;
     std::list<ValueFlow::Value>::const_iterator it;
     for (it = mImpl->mValues->begin(); it != mImpl->mValues->end(); ++it) {
         if (it->isTokValue() && it->tokvalue && it->tokvalue->tokType() == Token::eString) {
-            const std::size_t length = getStrLength(it->tokvalue);
+            const int length = getStrLength(it->tokvalue);
             if (!ret || length > maxlength) {
                 maxlength = length;
                 ret = it->tokvalue;
@@ -1746,17 +1746,17 @@ bool Token::addValue(const ValueFlow::Value &value)
 
 void Token::assignProgressValues(Token *tok)
 {
-    unsigned int total_count = 0;
+    int total_count = 0;
     for (Token *tok2 = tok; tok2; tok2 = tok2->next())
         ++total_count;
-    unsigned int count = 0;
+    int count = 0;
     for (Token *tok2 = tok; tok2; tok2 = tok2->next())
         tok2->mImpl->mProgressValue = count++ * 100 / total_count;
 }
 
 void Token::assignIndexes()
 {
-    unsigned int index = (mPrevious ? mPrevious->mImpl->mIndex : 0) + 1;
+    int index = (mPrevious ? mPrevious->mImpl->mIndex : 0) + 1;
     for (Token *tok = this; tok; tok = tok->next())
         tok->mImpl->mIndex = index++;
 }
diff --git a/lib/token.h b/lib/token.h
index c934c001b..2a0acf374 100644
--- a/lib/token.h
+++ b/lib/token.h
@@ -51,10 +51,10 @@ struct TokensFrontBack {
 };
 
 struct TokenImpl {
-    unsigned int mVarId;
-    unsigned int mFileIndex;
-    unsigned int mLineNumber;
-    unsigned int mColumn;
+    int mVarId;
+    int mFileIndex;
+    int mLineNumber;
+    int mColumn;
 
     // AST..
     Token *mAstOperand1;
@@ -74,12 +74,12 @@ struct TokenImpl {
      * A value from 0-100 that provides a rough idea about where in the token
      * list this token is located.
      */
-    unsigned int mProgressValue;
+    int mProgressValue;
 
     /**
      * Token index. Position in token list
      */
-    unsigned int mIndex;
+    int mIndex;
 
     // original name like size_t
     std::string* mOriginalName;
@@ -288,7 +288,7 @@ public:
      * @return true if given token matches with given pattern
      *         false if given token does not match with given pattern
      */
-    static bool Match(const Token *tok, const char pattern[], unsigned int varid = 0);
+    static bool Match(const Token *tok, const char pattern[], int varid = 0);
 
     /**
      * @return length of C-string.
@@ -297,7 +297,7 @@ public:
      *
      * @param tok token with C-string
      **/
-    static std::size_t getStrLength(const Token *tok);
+    static int getStrLength(const Token *tok);
 
     /**
      * @return sizeof of C-string.
@@ -306,7 +306,7 @@ public:
      *
      * @param tok token with C-string
      **/
-    static std::size_t getStrSize(const Token *tok);
+    static int getStrSize(const Token *tok);
 
     /**
      * @return char of C-string at index (possible escaped "\\n")
@@ -316,7 +316,7 @@ public:
      * @param tok token with C-string
      * @param index position of character
      **/
-    static std::string getCharAt(const Token *tok, std::size_t index);
+    static std::string getCharAt(const Token *tok, MathLib::bigint index);
 
     const ValueType *valueType() const {
         return mImpl->mValueType;
@@ -586,18 +586,18 @@ public:
 
     static const Token *findsimplematch(const Token * const startTok, const char pattern[]);
     static const Token *findsimplematch(const Token * const startTok, const char pattern[], const Token * const end);
-    static const Token *findmatch(const Token * const startTok, const char pattern[], const unsigned int varId = 0U);
-    static const Token *findmatch(const Token * const startTok, const char pattern[], const Token * const end, const unsigned int varId = 0U);
+    static const Token *findmatch(const Token * const startTok, const char pattern[], const int varId = 0);
+    static const Token *findmatch(const Token * const startTok, const char pattern[], const Token * const end, const int varId = 0);
     static Token *findsimplematch(Token * const startTok, const char pattern[]) {
         return const_cast<Token *>(findsimplematch(const_cast<const Token *>(startTok), pattern));
     }
     static Token *findsimplematch(Token * const startTok, const char pattern[], const Token * const end) {
         return const_cast<Token *>(findsimplematch(const_cast<const Token *>(startTok), pattern, end));
     }
-    static Token *findmatch(Token * const startTok, const char pattern[], const unsigned int varId = 0U) {
+    static Token *findmatch(Token * const startTok, const char pattern[], const int varId = 0) {
         return const_cast<Token *>(findmatch(const_cast<const Token *>(startTok), pattern, varId));
     }
-    static Token *findmatch(Token * const startTok, const char pattern[], const Token * const end, const unsigned int varId = 0U) {
+    static Token *findmatch(Token * const startTok, const char pattern[], const Token * const end, const int varId = 0) {
         return const_cast<Token *>(findmatch(const_cast<const Token *>(startTok), pattern, end, varId));
     }
 
@@ -615,26 +615,26 @@ public:
      *         0 if needle was empty string
      *        -1 if needle was not found
      */
-    static int multiCompare(const Token *tok, const char *haystack, unsigned int varid);
+    static int multiCompare(const Token *tok, const char *haystack, int varid);
 
-    unsigned int fileIndex() const {
+    int fileIndex() const {
         return mImpl->mFileIndex;
     }
-    void fileIndex(unsigned int indexOfFile) {
+    void fileIndex(int indexOfFile) {
         mImpl->mFileIndex = indexOfFile;
     }
 
-    unsigned int linenr() const {
+    int linenr() const {
         return mImpl->mLineNumber;
     }
-    void linenr(unsigned int lineNumber) {
+    void linenr(int lineNumber) {
         mImpl->mLineNumber = lineNumber;
     }
 
-    unsigned int col() const {
+    int col() const {
         return mImpl->mColumn;
     }
-    void col(unsigned int c) {
+    void col(int c) {
         mImpl->mColumn = c;
     }
 
@@ -667,10 +667,10 @@ public:
     }
 
 
-    unsigned int varId() const {
+    int varId() const {
         return mImpl->mVarId;
     }
-    void varId(unsigned int id) {
+    void varId(int id) {
         mImpl->mVarId = id;
         if (id != 0) {
             tokType(eVariable);
@@ -873,7 +873,7 @@ public:
     static void move(Token *srcStart, Token *srcEnd, Token *newLocation);
 
     /** Get progressValue (0 - 100) */
-    unsigned int progressValue() const {
+    int progressValue() const {
         return mImpl->mProgressValue;
     }
 
@@ -981,7 +981,7 @@ public:
     const ValueFlow::Value * getValueLE(const MathLib::bigint val, const Settings *settings) const;
     const ValueFlow::Value * getValueGE(const MathLib::bigint val, const Settings *settings) const;
 
-    const ValueFlow::Value * getInvalidValue(const Token *ftok, unsigned int argnr, const Settings *settings) const;
+    const ValueFlow::Value * getInvalidValue(const Token *ftok, int argnr, const Settings *settings) const;
 
     const ValueFlow::Value * getContainerSizeValue(const MathLib::bigint val) const {
         if (!mImpl->mValues)
@@ -1006,7 +1006,7 @@ public:
             mImpl->mValues->remove_if(pred);
     }
 
-    unsigned int index() const {
+    int index() const {
         return mImpl->mIndex;
     }
 
@@ -1107,7 +1107,7 @@ private:
     void update_property_char_string_literal();
 
     /** Internal helper function to avoid excessive string allocations */
-    void astStringVerboseRecursive(std::string& ret, const unsigned int indent1 = 0U, const unsigned int indent2 = 0U) const;
+    void astStringVerboseRecursive(std::string& ret, const int indent1 = 0, const int indent2 = 0) const;
 
 public:
     void astOperand1(Token *tok);