1)internal check found a 'findmatch' with simple string argument;

2)Style: uniform 'while (...)' when inside it there's an assignment;
3)Replace '0' with 'NULL' where there's comparison with a pointer.

lib/checkautovariables.cpp

@@ -251,7 +251,7 @@ bool CheckAutoVariables::returnTemporary(const Token *tok) const
 {
     if (!Token::Match(tok, "return %var% ("))
         return false;
-    return bool(0 != Token::findmatch(_tokenizer->tokens(), ("std :: string " + tok->next()->str() + " (").c_str()));
+    return bool(NULL != Token::findmatch(_tokenizer->tokens(), ("std :: string " + tok->next()->str() + " (").c_str()));
 }
 
 //---------------------------------------------------------------------------

lib/checkclass.cpp

@@ -1345,7 +1345,7 @@ static unsigned int countParameters(const Token *tok)
         return 0;
 
     unsigned int numpar = 1;
-    while ((tok = tok->nextArgument()))
+    while (NULL != (tok = tok->nextArgument()))
         numpar++;
 
     return numpar;

lib/checkmemoryleak.cpp

@@ -445,7 +445,7 @@ CheckMemoryLeak::AllocType CheckMemoryLeak::functionReturnType(const Token *tok,
 
     // Check if return pointer is allocated..
     AllocType allocType = No;
-    while (0 != (tok = tok->next())) {
+    while (NULL != (tok = tok->next())) {
         if (Token::Match(tok, "%varid% =", varid)) {
             allocType = getAllocationType(tok->tokAt(2), varid, callstack);
         }
@@ -516,7 +516,7 @@ const char *CheckMemoryLeak::functionArgAlloc(const Token *tok, unsigned int tar
     // Check if pointer is allocated.
     unsigned int indentlevel = 0;
     int realloc = 0;
-    while (0 != (tok = tok->next())) {
+    while (NULL != (tok = tok->next())) {
         if (tok->str() == "{")
             ++indentlevel;
         else if (tok->str() == "}") {
@@ -608,7 +608,7 @@ static unsigned int countParameters(const Token *tok)
         return 0;
 
     unsigned int numpar = 1;
-    while ((tok = tok->nextArgument()))
+    while (NULL != (tok = tok->nextArgument()))
         numpar++;
 
     return numpar;
@@ -1670,7 +1670,7 @@ void CheckMemoryLeakInFunction::simplifycode(Token *tok)
 
                 // Delete "if { dealloc|assign|use ; return ; }"
                 else if (Token::Match(tok2, "[;{}] if { dealloc|assign|use ; return ; }") &&
-                         !Token::findmatch(tok, "if alloc ;")) {
+                         !Token::findsimplematch(tok, "if alloc ;")) {
                     Token::eraseTokens(tok2, tok2->tokAt(8));
                     if (Token::simpleMatch(tok2->next(), "else"))
                         tok2->deleteNext();
@@ -2356,7 +2356,7 @@ void CheckMemoryLeakInFunction::parseFunctionScope(const Token *tok, const Token
             const Token *vartok = tok->tokAt(2);
             checkScope(tok->next(), vartok->str(), vartok->varId(), classmember, sz);
         }
-    } while (0 != (tok = tok->next()));
+    } while (NULL != (tok = tok->next()));
 }
 
 void CheckMemoryLeakInFunction::check()

lib/checknullpointer.cpp

@@ -308,8 +308,10 @@ void CheckNullPointer::nullPointerAfterLoop()
         // Is this checking inconclusive?
         bool inconclusive = false;
 
+        if (!tok2)
+            continue;
         // Check if the variable is dereferenced after the while loop
-        while (0 != (tok2 = tok2 ? tok2->next() : 0)) {
+        while (NULL != (tok2 = tok2->next())) {
             // inner and outer scopes
             if (tok2->str() == "{" || tok2->str() == "}") {
                 // Not inconclusive: bail out

lib/checkother.cpp

@@ -1143,7 +1143,7 @@ void CheckOther::invalidFunctionUsage()
                 sprintfOverlappingDataError(tok2->next(), tok2->next()->str());
                 break;
             }
-        } while ((tok2 = tok2->nextArgument()) != NULL);
+        } while (NULL != (tok2 = tok2->nextArgument()));
     }
 }
 

lib/checkuninitvar.cpp

@@ -668,7 +668,7 @@ private:
                     if (Token::Match(tok2->tokAt(-2), "[(,] *") || Token::Match(tok2->next(), ". %var%")) {
                         // find function call..
                         const Token *functionCall = tok2;
-                        while (0 != (functionCall = functionCall ? functionCall->previous() : 0)) {
+                        while (NULL != (functionCall = functionCall ? functionCall->previous() : 0)) {
                             if (functionCall->str() == "(")
                                 break;
                             if (functionCall->str() == ")")

lib/preprocessor.cpp

@@ -2334,7 +2334,7 @@ public:
                 tok = tok->next();
             if (tok) {
                 bool optcomma = false;
-                while ((tok = tok->next()) != NULL) {
+                while (NULL != (tok = tok->next())) {
                     std::string str = tok->str();
                     if (str == "##")
                         continue;

lib/tokenize.cpp

@@ -2554,7 +2554,7 @@ void Tokenizer::labels()
             // Simplify labels in the executable scope..
             unsigned int indentlevel = 0;
             unsigned int indentroundbraces = 0;
-            while (0 != (tok = tok->next())) {
+            while (NULL != (tok = tok->next())) {
                 if (tok->str() == "{")
                     ++indentlevel;
                 else if (tok->str() == "}") {
@@ -2571,7 +2571,7 @@ void Tokenizer::labels()
                     --indentroundbraces;
                 }
                 if (!indentroundbraces && tok->str() == "case") {
-                    while (0 != (tok = tok->next())) {
+                    while (NULL != (tok = tok->next())) {
                         if (Token::Match(tok->previous(), "%any% :"))
                             break;
                     }
@@ -2737,7 +2737,7 @@ std::set<std::string> Tokenizer::simplifyTemplatesExpandSpecialized()
         tok->deleteThis();
 
         // Use this special template in the code..
-        while (0 != (tok2 = const_cast<Token *>(Token::findmatch(tok2, pattern.c_str())))) {
+        while (NULL != (tok2 = const_cast<Token *>(Token::findmatch(tok2, pattern.c_str())))) {
             Token::eraseTokens(tok2, Token::findsimplematch(tok2, "("));
             tok2->str(name);
         }
@@ -4797,7 +4797,7 @@ bool Tokenizer::simplifyIfAddBraces()
         // * if (cond) for (;;) break;
         // * if (cond1) if (cond2) { }
         // * if (cond1) if (cond2) ; else ;
-        while ((tempToken = tempToken->next()) != NULL) {
+        while (NULL != (tempToken = tempToken->next())) {
             if (tempToken->str() == "{") {
                 if (Token::simpleMatch(tempToken->previous(),"else {")) {
                     if (innerIf)
@@ -5779,7 +5779,7 @@ void Tokenizer::simplifyVarDecl(bool only_k_r_fpar)
                 insertTokens(tok2, type0, typelen);
                 std::stack<Token *> link1;
                 std::stack<Token *> link2;
-                while (((typelen--) > 0) && (0 != (tok2 = tok2->next()))) {
+                while (((typelen--) > 0) && (NULL != (tok2 = tok2->next()))) {
                     if (tok2->str() == "(")
                         link1.push(tok2);
                     else if (tok2->str() == ")" && !link1.empty()) {
@@ -6357,7 +6357,7 @@ bool Tokenizer::simplifyLogicalOperators()
                 continue;
 
             const Token *tok2 = tok;
-            while (0 != (tok2 = tok2->previous())) {
+            while (NULL != (tok2 = tok2->previous())) {
                 if (tok2->str() == ")")
                     tok2 = tok2->link();
                 else if (Token::Match(tok2, "(|;|{|}"))