#6269 false positives in case of overloaded standard library functions. Detect memset() with proper argument cound, using new function numberOfArguments()

lib/astutils.cpp

@@ -302,3 +302,17 @@ bool isVariableChanged(const Token *start, const Token *end, const unsigned int
     }
     return false;
 }
+
+int numberOfArguments(const Token *start)
+{
+    int arguments=0;
+    const Token* const openBracket = start->next();
+    if (openBracket && openBracket->str()=="(" && openBracket->next() && openBracket->next()->str()!=")") {
+        const Token* argument=openBracket->next();
+        while (argument) {
+            ++arguments;
+            argument = argument->nextArgument();
+        }
+    }
+    return arguments;
+}

lib/astutils.h

@@ -67,4 +67,10 @@ bool isWithoutSideEffects(bool cpp, const Token* tok);
 /** Is variable changed in block of code? */
 bool isVariableChanged(const Token *start, const Token *end, const unsigned int varid);
 
+/** Determines the number of arguments - if token is a function call or macro
+ * @param start token which is supposed to be the function/macro name.
+ * \return Number of arguments
+ */
+int numberOfArguments(const Token *start);
+
 #endif // astutilsH

lib/checkother.cpp

@@ -1076,7 +1076,7 @@ void CheckOther::checkMemsetZeroBytes()
     for (std::size_t i = 0; i < functions; ++i) {
         const Scope * scope = symbolDatabase->functionScopes[i];
         for (const Token* tok = scope->classStart->next(); tok != scope->classEnd; tok = tok->next()) {
-            if (Token::simpleMatch(tok, "memset (")) {
+            if (Token::simpleMatch(tok, "memset (") && (numberOfArguments(tok)==3)) {
                 const Token* lastParamTok = tok->next()->link()->previous();
                 if (lastParamTok->str() == "0")
                     memsetZeroBytesError(tok, tok->strAt(2));

lib/library.cpp

@@ -869,15 +869,7 @@ bool Library::isNotLibraryFunction(const Token *ftok) const
     if (ftok->varId())
         return true;
 
-    int callargs = 0;
-    for (const Token *tok = ftok->tokAt(2); tok && tok->str() != ")"; tok = tok->next()) {
-        if (callargs == 0)
-            callargs = 1;
-        if (tok->str() == ",")
-            callargs++;
-        else if (tok->link() && Token::Match(tok, "<|(|["))
-            tok = tok->link();
-    }
+    int callargs = numberOfArguments(ftok);
     const std::map<std::string, std::map<int, ArgumentChecks> >::const_iterator it = argumentChecks.find(functionName(ftok));
     if (it == argumentChecks.end())
         return (callargs != 0);

lib/symboldatabase.cpp

@@ -1432,8 +1432,7 @@ void SymbolDatabase::validate() const
         const Scope* scope = functionScopes[i];
         const Function* function = scope->function;
         if (scope->isExecutable() && !function) {
-        if (_settings->debugwarnings)
-            {
+            if (_settings->debugwarnings) {
                 const std::list<const Token*> callstack(1, scope->classDef);
                 const std::string msg = std::string("executable scope '") + scope->classDef->str() + "' with unknown function";
                 const ErrorLogger::ErrorMessage errmsg(callstack, &_tokenizer->list, Severity::debug,

lib/token.cpp

@@ -758,9 +758,9 @@ Token* Token::nextArgument() const
         else if (tok->link() && Token::Match(tok, "(|{|[|<"))
             tok = tok->link();
         else if (Token::Match(tok, ")|;"))
-            return 0;
+            return nullptr;
     }
-    return 0;
+    return nullptr;
 }
 
 Token* Token::nextArgumentBeforeCreateLinks2() const
@@ -775,9 +775,9 @@ Token* Token::nextArgumentBeforeCreateLinks2() const
             if (temp)
                 tok = temp;
         } else if (Token::Match(tok, ")|;"))
-            return 0;
+            return nullptr;
     }
-    return 0;
+    return nullptr;
 }
 
 Token* Token::nextTemplateArgument() const
@@ -788,9 +788,9 @@ Token* Token::nextTemplateArgument() const
         else if (tok->link() && Token::Match(tok, "(|{|[|<"))
             tok = tok->link();
         else if (Token::Match(tok, ">|;"))
-            return 0;
+            return nullptr;
     }
-    return 0;
+    return nullptr;
 }
 
 const Token * Token::findClosingBracket() const
@@ -846,7 +846,7 @@ const Token *Token::findsimplematch(const Token *startTok, const char pattern[],
         if (Token::simpleMatch(tok, pattern))
             return tok;
     }
-    return 0;
+    return nullptr;
 }
 
 const Token *Token::findmatch(const Token *startTok, const char pattern[], unsigned int varId)
@@ -855,7 +855,7 @@ const Token *Token::findmatch(const Token *startTok, const char pattern[], unsig
         if (Token::Match(tok, pattern, varId))
             return tok;
     }
-    return 0;
+    return nullptr;
 }
 
 const Token *Token::findmatch(const Token *startTok, const char pattern[], const Token *end, unsigned int varId)
@@ -864,7 +864,7 @@ const Token *Token::findmatch(const Token *startTok, const char pattern[], const
         if (Token::Match(tok, pattern, varId))
             return tok;
     }
-    return 0;
+    return nullptr;
 }
 
 void Token::insertToken(const std::string &tokenStr, bool prepend)

test/testother.cpp

@@ -3275,6 +3275,16 @@ private:
               "    memset(p, sizeof(p), i);\n"
               "}\n");
         ASSERT_EQUALS("", errout.str());
+
+        // #6269 false positives in case of overloaded standard library functions
+        check("class c {\n"
+              "  void memset( int i );\n"
+              "  void f( void )   {\n"
+              "     memset( 0 );\n"
+              "  }\n"
+              "};");
+        ASSERT_EQUALS("", errout.str());
+
     }
 
     void memsetInvalid2ndParam() {