switch some functions from const to static, as cppcheck suggests.

lib/checkio.cpp

@@ -349,7 +349,6 @@ void CheckIO::ioWithoutPositioningError(const Token *tok)
 
 void CheckIO::readWriteOnlyFileError(const Token *tok)
 {
-
     reportError(tok, Severity::error,
                 "readWriteOnlyFile", "Read operation on a file that was opened only for writing.", CWE664, false);
 }
@@ -2001,7 +2000,7 @@ void CheckIO::invalidPrintfArgTypeError_float(const Token* tok, unsigned int num
     reportError(tok, severity, "invalidPrintfArgType_float", errmsg.str(), CWE686, false);
 }
 
-Severity::SeverityType CheckIO::getSeverity(const CheckIO::ArgumentInfo *argInfo) const
+Severity::SeverityType CheckIO::getSeverity(const CheckIO::ArgumentInfo *argInfo)
 {
     return (argInfo && argInfo->typeToken && !argInfo->typeToken->originalName().empty()) ? Severity::portability : Severity::warning;
 }

lib/checkio.h

@@ -128,7 +128,7 @@ private:
     void invalidLengthModifierError(const Token* tok, unsigned int numFormat, const std::string& modifier);
     void invalidScanfFormatWidthError(const Token* tok, unsigned int numFormat, int width, const Variable *var, char c);
     static void argumentType(std::ostream & s, const ArgumentInfo * argInfo);
-    Severity::SeverityType getSeverity(const ArgumentInfo *argInfo) const;
+    static Severity::SeverityType getSeverity(const ArgumentInfo *argInfo);
 
     void getErrorMessages(ErrorLogger *errorLogger, const Settings *settings) const {
         CheckIO c(nullptr, settings, errorLogger);

lib/platform.h

@@ -34,13 +34,13 @@ namespace cppcheck {
     */
     class CPPCHECKLIB Platform {
     private:
-        long long min_value(int bit) const {
+        static long long min_value(int bit) {
             if (bit >= 64)
                 return 1LL << 63;
             return -(1LL << (bit-1));
         }
 
-        long long max_value(int bit) const {
+        static long long max_value(int bit) {
             if (bit >= 64)
                 return (~0ULL) >> 1;
             return (1LL << (bit-1)) - 1LL;

lib/settings.h

@@ -100,12 +100,12 @@ public:
     bool verbose;
 
     /** @brief Request termination of checking */
-    void terminate(bool t = true) {
+    static void terminate(bool t = true) {
         Settings::_terminated = t;
     }
 
     /** @brief termination requested? */
-    bool terminated() const {
+    static bool terminated() {
         return Settings::_terminated;
     }
 

lib/tokenize.cpp

@@ -7194,7 +7194,7 @@ void Tokenizer::simplifyNestedStrcat()
 // Check if this statement is a duplicate definition.  A duplicate
 // definition will hide the enumerator within it's scope so just
 // skip the entire scope of the duplicate.
-bool Tokenizer::duplicateDefinition(Token ** tokPtr) const
+bool Tokenizer::duplicateDefinition(Token ** tokPtr)
 {
     // check for an end of definition
     const Token * tok = *tokPtr;
@@ -8068,7 +8068,7 @@ const Token * Tokenizer::findGarbageCode() const
     return nullptr;
 }
 
-bool Tokenizer::isGarbageExpr(const Token *start, const Token *end) const
+bool Tokenizer::isGarbageExpr(const Token *start, const Token *end)
 {
     std::set<std::string> controlFlowKeywords;
     controlFlowKeywords.insert("goto");

lib/tokenize.h

@@ -582,7 +582,7 @@ private:
     const Token * findGarbageCode() const;
 
     /** Detect garbage expression */
-    bool isGarbageExpr(const Token *start, const Token *end) const;
+    static bool isGarbageExpr(const Token *start, const Token *end);
 
     /**
      * Remove __declspec()
@@ -679,7 +679,7 @@ private:
     /**
      * check for duplicate enum definition
      */
-    bool duplicateDefinition(Token **tokPtr) const;
+    static bool duplicateDefinition(Token **tokPtr);
 
     /**
      * report error message
@@ -794,7 +794,7 @@ public:
     */
     static const Token * startOfExecutableScope(const Token * tok);
 
-    bool isMaxTime() const {
+    static bool isMaxTime() {
 #ifdef MAXTIME
         return (std::time(0) > maxtime);
 #else