Value flow: refactorings, write debug warning if iterating too far

lib/checkother.cpp

@@ -2158,8 +2158,10 @@ void CheckOther::checkZeroDivision()
             std::list<ValueFlow::Value>::const_iterator it;
             for (it = values.begin(); it != values.end(); ++it) {
                 if (it->intvalue == 0) {
-                    if (!it->link || _settings->isEnabled("warning"))
+                    if (it->condition == NULL)
                         zerodivError(tok);
+                    else if (_settings->isEnabled("warning"))
+                        zerodivcondError(it->condition,tok);
                 }
             }
         }
@@ -2176,6 +2178,11 @@ void CheckOther::checkZeroDivisionOrUselessCondition()
 {
     if (!_settings->isEnabled("warning"))
         return;
+        
+    // Use experimental checking instead based on value flow analysis
+    if (_settings->valueFlow)
+		return;
+        
     const SymbolDatabase *symbolDatabase = _tokenizer->getSymbolDatabase();
     const std::size_t numberOfFunctions = symbolDatabase->functionScopes.size();
     for (std::size_t functionIndex = 0; functionIndex < numberOfFunctions; ++functionIndex) {

lib/tokenize.cpp

@@ -1605,7 +1605,7 @@ bool Tokenizer::tokenize(std::istream &code,
         list.createAst();
 
         if (_settings->valueFlow)
-            ValueFlow::setValues(list.front());
+            ValueFlow::setValues(&list, _errorLogger, _settings);
 
         return true;
     }

lib/valueflow.cpp

@@ -17,20 +17,27 @@
  */
 
 #include "valueflow.h"
-#include "token.h"
+#include "errorlogger.h"
 #include "mathlib.h"
+#include "settings.h"
+#include "symboldatabase.h"
+#include "token.h"
+#include "tokenlist.h"
 
-static void valueFlowBeforeCondition(Token *tokens)
+static void valueFlowBeforeCondition(TokenList *tokenlist, ErrorLogger *errorLogger, const Settings *settings)
 {
-    for (Token *tok = tokens; tok; tok = tok->next()) {
+    for (Token *tok = tokenlist->front(); tok; tok = tok->next()) {
         unsigned int varid;
         MathLib::bigint num;
+        const Variable *var;
         if (Token::Match(tok, "==|!=|>=|<=") && tok->astOperand1() && tok->astOperand2()) {
             if (tok->astOperand1()->isName() && tok->astOperand2()->isNumber()) {
                 varid = tok->astOperand1()->varId();
+                var = tok->astOperand1()->variable();
                 num = MathLib::toLongNumber(tok->astOperand2()->str());
             } else if (tok->astOperand1()->isNumber() && tok->astOperand2()->isName()) {
                 varid = tok->astOperand2()->varId();
+                var = tok->astOperand2()->variable();
                 num = MathLib::toLongNumber(tok->astOperand1()->str());
             } else {
                 continue;
@@ -38,9 +45,11 @@ static void valueFlowBeforeCondition(Token *tokens)
         } else if (Token::Match(tok->previous(), "if|while ( %var% %oror%|&&|)") ||
                    Token::Match(tok, "%oror%|&& %var% %oror%|&&|)")) {
             varid = tok->next()->varId();
+            var = tok->next()->variable();
             num = 0;
         } else if (tok->str() == "!" && tok->astOperand1() && tok->astOperand1()->isName()) {
             varid = tok->astOperand1()->varId();
+            var = tok->astOperand1()->variable();
             num = 0;
         } else {
             continue;
@@ -50,26 +59,33 @@ static void valueFlowBeforeCondition(Token *tokens)
             continue;
 
         struct ValueFlow::Value val;
-        val.link = tok;
+        val.condition = tok;
         val.intvalue = num;
 
-        for (Token *tok2 = tok->previous(); tok2; tok2 = tok2->previous()) {
-            if (tok2->varId() == varid)
+        for (Token *tok2 = tok->previous(); ; tok2 = tok2->previous()) {
+            if (!tok2) {
+                if (settings->debugwarnings) {
+                    std::list<ErrorLogger::ErrorMessage::FileLocation> callstack;
+                    callstack.push_back(ErrorLogger::ErrorMessage::FileLocation(tok,tokenlist));
+                    ErrorLogger::ErrorMessage errmsg(callstack, Severity::debug, "iterated too far", "debugValueFlowBeforeCondition", false);
+                    errorLogger->reportErr(errmsg);
+                }
+                break;
+            }
+
+            if (tok2->varId() == varid) {
                 tok2->values.push_back(val);
-            if (tok2->str() == "{") {
-                if (!Token::simpleMatch(tok2->previous(), ") {"))
-                    break;
-                if (!Token::simpleMatch(tok2->previous()->link()->previous(), "if ("))
+                if (var && tok2 == var->nameToken())
                     break;
             }
         }
     }
 }
 
-void ValueFlow::setValues(Token *tokens)
+void ValueFlow::setValues(TokenList *tokenlist, ErrorLogger *errorLogger, const Settings *settings)
 {
-    for (Token *tok = tokens; tok; tok = tok->next())
+    for (Token *tok = tokenlist->front(); tok; tok = tok->next())
         tok->values.clear();
 
-    valueFlowBeforeCondition(tokens);
+    valueFlowBeforeCondition(tokenlist, errorLogger, settings);
 }

lib/valueflow.h

@@ -22,15 +22,17 @@
 //---------------------------------------------------------------------------
 
 class Token;
+class TokenList;
+class ErrorLogger;
+class Settings;
 
 namespace ValueFlow {
-
     struct Value {
-        const Token *link;
+        const Token *condition;
         long long    intvalue;
     };
 
-    void setValues(Token *tokens);
+    void setValues(TokenList *tokenlist, ErrorLogger *errorLogger, const Settings *settings);
 }
 
 #endif // valueflowH