Add into IF_STMT node analysis check for if(var).

1 files changed, 32 insertions, 3 deletions

diff --git a/src/analysis/statement.cpp b/src/analysis/statement.cpp
index 50c870a..a226483 100644
--- a/src/analysis/statement.cpp
+++ b/src/analysis/statement.cpp
@@ -28,6 +28,7 @@
 #include "nodes/expr/eq_expr.h"
 #include "nodes/expr/indirect_ref.h"
 #include "nodes/expr/modify_expr.h"
+#include "nodes/expr/ne_expr.h"
 #include "nodes/expr/pointerplus_expr.h"
 
 #include "nodes/stmt/if_stmt.h"
@@ -46,7 +47,7 @@ WalkItem analyseIfStmt(IfStmtNode *node, WalkItem wi)
         return wi;
 
     if (node->condition->nodeType == EQ_EXPR)
-    {
+    {   // if (... == ..)
         EqExprNode *eq = static_cast<EqExprNode*>(node->condition);
         // need atleast two operands for EQ_EXPR node
         if (eq->args.size() < 2)
@@ -70,8 +71,36 @@ WalkItem analyseIfStmt(IfStmtNode *node, WalkItem wi)
             walkTree(node->elseNode, wi);
             wi.stopWalking = true;
 
-            // need aslo on parent remove variable too
-            // probably wi should have pointer to parent
+            // need check what return present
+            return wi;
+        }
+    }
+    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)
+            return wi;
+
+        // PARM_DECL?
+        Node *node1 = eq->args[0];
+        // INTEGER_CST?
+        Node *node2 = eq->args[1];
+        // if (var != const)
+        if (node1->nodeType == PARM_DECL &&
+            node2->nodeType == INTEGER_CST &&
+            wi.checkNullVars.find(node1->label) != wi.checkNullVars.end() &&
+            node2->label == "0")
+        {
+            // found check for parameter and 0.
+            // walking to then branch
+            WalkItem wi2 = wi;
+            wi2.checkNullVars.erase(node1->label);
+            // From then branch remove variable what we just found.
+            walkTree(node->thenNode, wi2);
+            // walking else node with all variables
+            walkTree(node->elseNode, wi);
+            wi.stopWalking = true;
             return wi;
         }
     }