Fix some issues in test6.

Now if variable check happend before other code variable will not trigger warning.
Example:
    if (!a)
        return;
    *a = 10;

3 files changed, 47 insertions, 21 deletions

diff --git a/src/analysis/analysis.cpp b/src/analysis/analysis.cpp
index 011fbf1..86fd683 100644
--- a/src/analysis/analysis.cpp
+++ b/src/analysis/analysis.cpp
@@ -42,6 +42,19 @@
 namespace Analysis
 {
 
+// remove check null vars.
+void removeCheckNullVars(WalkItem &wi)
+{
+    FOR_EACH (std::set<std::string>::const_iterator, it, wi.removeNullVars)
+    {
+        // found var for deletion
+        if (wi.checkNullVars.find(*it) != wi.checkNullVars.end())
+        {
+            wi.checkNullVars.erase(*it);
+        }
+    }
+}
+
 void startWalkTree(Node *node)
 {
     WalkItem wi;
@@ -55,15 +68,8 @@ void walkTree(Node *node, const WalkItem &wi, WalkItem &wo)
         return;
 
     WalkItem wi2 = wi;
-    FOR_EACH (std::set<std::string>::const_iterator, it, wi2.removeNullVars)
-    {
-        // found var for deletion
-        if (wi2.checkNullVars.find(*it) != wi2.checkNullVars.end())
-        {
-            wi2.checkNullVars.erase(*it);
-        }
-    }
     analyseNode(node, wi2, wo);
+    removeCheckNullVars(wi2);
 
     if (wo.stopWalking)
     {
@@ -111,28 +117,34 @@ void analyseNode(Node *node, const WalkItem &wi, WalkItem &wo)
         Log::log("\n");
     }
 
+    WalkItem wi2 = wi;
     wo = wi;
 
+    // remove check for vars what was requested from some childs.
+    // Except IF_STMT. Removing handled inside analyse function.
+    if (node->nodeType != IF_STMT)
+        removeCheckNullVars(wi2);
+
     // searching function declaration
     switch (node->nodeType)
     {
         case FUNCTION_DECL:
-            analyseFunction(static_cast<FunctionDeclNode*>(node), wi, wo);
+            analyseFunction(static_cast<FunctionDeclNode*>(node), wi2, wo);
             break;
         case ADDR_EXPR:
-            analyseAddrExpr(static_cast<AddrExprNode*>(node), wi, wo);
+            analyseAddrExpr(static_cast<AddrExprNode*>(node), wi2, wo);
             break;
         case MODIFY_EXPR:
-            analyseModifyExpr(static_cast<ModifyExprNode*>(node), wi, wo);
+            analyseModifyExpr(static_cast<ModifyExprNode*>(node), wi2, wo);
             break;
         case POINTER_PLUS_EXPR:
-            analysePointerPlusExpr(static_cast<PointerPlusExprNode*>(node), wi, wo);
+            analysePointerPlusExpr(static_cast<PointerPlusExprNode*>(node), wi2, wo);
             break;
         case VAR_DECL:
-            analyseVarDecl(static_cast<VarDeclNode*>(node), wi, wo);
+            analyseVarDecl(static_cast<VarDeclNode*>(node), wi2, wo);
             break;
         case IF_STMT:
-            analyseIfStmt(static_cast<IfStmtNode*>(node), wi, wo);
+            analyseIfStmt(static_cast<IfStmtNode*>(node), wi2, wo);
             break;
         default:
             break;
diff --git a/src/analysis/analysis.h b/src/analysis/analysis.h
index bfc3327..596988c 100644
--- a/src/analysis/analysis.h
+++ b/src/analysis/analysis.h
@@ -34,6 +34,8 @@ namespace Analysis
     void analyseNode(Node *node, const WalkItem &wi, WalkItem &wo);
 
     int findBackLocation(Node *node);
+
+    void removeCheckNullVars(WalkItem &wi);
 }
 
 #endif // ANALYSIS_ANALYSIS_H
diff --git a/src/analysis/statement.cpp b/src/analysis/statement.cpp
index a585adb..4d948d3 100644
--- a/src/analysis/statement.cpp
+++ b/src/analysis/statement.cpp
@@ -57,7 +57,7 @@ void analyseIfStmt(IfStmtNode *node, const WalkItem &wi, WalkItem &wo)
         Node *node1 = eq->args[0];
         // INTEGER_CST?
         Node *node2 = eq->args[1];
-        // if (var == const)
+        // if (var == 0)
         if (node1->nodeType == PARM_DECL &&
             node2->nodeType == INTEGER_CST &&
             wi.checkNullVars.find(node1->label) != wi.checkNullVars.end() &&
@@ -67,10 +67,13 @@ void analyseIfStmt(IfStmtNode *node, const WalkItem &wi, WalkItem &wo)
             // found check for parameter and 0.
             // walking to then branch
             walkTree(node->thenNode, wi2, wo);
+            wo.removeNullVars.clear();
+
             // From else branch remove variable what we just found.
             wi2 = wi;
             wi2.checkNullVars.erase(node1->label);
             walkTree(node->elseNode, wi2, wo);
+            wo.removeNullVars.clear();
             wo.stopWalking = true;
 
             //Log::log("add removeNullVars: %s\n", node1->label.c_str());
@@ -79,20 +82,21 @@ void analyseIfStmt(IfStmtNode *node, const WalkItem &wi, WalkItem &wo)
             wo.checkNullVars.erase(node1->label);
 
             // need check what return present
+            return;
         }
     }
     else if (node->condition->nodeType == NE_EXPR)
     {   // if (... != ..)
-        NeExprNode *eq = static_cast<NeExprNode*>(node->condition);
-        // need atleast two operands for EQ_EXPR node
-        if (eq->args.size() < 2)
+        NeExprNode *ne = static_cast<NeExprNode*>(node->condition);
+        // need atleast two operands for NE_EXPR node
+        if (ne->args.size() < 2)
             return;
 
         // PARM_DECL?
-        Node *node1 = eq->args[0];
+        Node *node1 = ne->args[0];
         // INTEGER_CST?
-        Node *node2 = eq->args[1];
-        // if (var != const)
+        Node *node2 = ne->args[1];
+        // if (var != 0)
         if (node1->nodeType == PARM_DECL &&
             node2->nodeType == INTEGER_CST &&
             wi.checkNullVars.find(node1->label) != wi.checkNullVars.end() &&
@@ -104,13 +108,21 @@ void analyseIfStmt(IfStmtNode *node, const WalkItem &wi, WalkItem &wo)
             wi2.checkNullVars.erase(node1->label);
             // From then branch remove variable what we just found.
             walkTree(node->thenNode, wi2, wo);
+            wo.removeNullVars.clear();
             wi2 = wi;
             // walking else node with all variables
             walkTree(node->elseNode, wi2, wo);
+            wo.removeNullVars.clear();
             wo.stopWalking = true;
             return;
         }
     }
+
+    // default case
+    walkTree(node->thenNode, wi, wo);
+    walkTree(node->elseNode, wi, wo);
+    wo.removeNullVars.clear();
+    wo.stopWalking = true;
 }
 
 }