From 77fd4910981d22cb1364c134454bf640e885c81b Mon Sep 17 00:00:00 2001
From: Andrei Karas <akaras@inbox.ru>
Date: Wed, 10 Jun 2015 16:49:44 +0300
Subject: Add basic analysis for IF_STMT.

---
 src/analysis/analysis.cpp  | 12 +++++++
 src/analysis/statement.cpp | 82 ++++++++++++++++++++++++++++++++++++++++++++++
 src/analysis/statement.h   | 33 +++++++++++++++++++
 3 files changed, 127 insertions(+)
 create mode 100644 src/analysis/statement.cpp
 create mode 100644 src/analysis/statement.h

(limited to 'src/analysis')

diff --git a/src/analysis/analysis.cpp b/src/analysis/analysis.cpp
index f64c5c1..18120b8 100644
--- a/src/analysis/analysis.cpp
+++ b/src/analysis/analysis.cpp
@@ -25,6 +25,7 @@
 #include "analysis/declaration.h"
 #include "analysis/expression.h"
 #include "analysis/function.h"
+#include "analysis/statement.h"
 #include "analysis/walkitem.h"
 
 #include "nodes/decl/function_decl.h"
@@ -34,6 +35,8 @@
 #include "nodes/expr/modify_expr.h"
 #include "nodes/expr/pointerplus_expr.h"
 
+#include "nodes/stmt/if_stmt.h"
+
 #include "localconsts.h"
 
 namespace Analysis
@@ -46,7 +49,11 @@ void startWalkTree(Node *node)
 
 void walkTree(Node *node, WalkItem wi)
 {
+    if (!node)
+        return;
+
     wi = analyseNode(node, wi);
+
     if (wi.stopWalking)
         return;
 
@@ -69,6 +76,9 @@ int findBackLocation(Node *node)
 
 WalkItem analyseNode(Node *node, WalkItem wi)
 {
+    if (!node)
+        return wi;
+
     // searching function declaration
     switch (node->nodeType)
     {
@@ -82,6 +92,8 @@ WalkItem analyseNode(Node *node, WalkItem wi)
             return analysePointerPlusExpr(static_cast<PointerPlusExprNode*>(node), wi);
         case VAR_DECL:
             return analyseVarDecl(static_cast<VarDeclNode*>(node), wi);
+        case IF_STMT:
+            return analyseIfStmt(static_cast<IfStmtNode*>(node), wi);
         default:
             break;
     }
diff --git a/src/analysis/statement.cpp b/src/analysis/statement.cpp
new file mode 100644
index 0000000..50c870a
--- /dev/null
+++ b/src/analysis/statement.cpp
@@ -0,0 +1,82 @@
+/*
+ *  Copyright (C) 2015  Andrei Karas
+ *
+ *  This file is part of AstDumper.
+ *
+ *  This program is free software; you can redistribute it and/or modify
+ *  it under the terms of the GNU General Public License as published by
+ *  the Free Software Foundation; either version 3 of the License, or
+ *  any later version.
+ *
+ *  This program is distributed in the hope that it will be useful,
+ *  but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ *  GNU General Public License for more details.
+ *
+ *  You should have received a copy of the GNU General Public License
+ *  along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#include "analysis/statement.h"
+
+#include "command.h"
+#include "logger.h"
+
+#include "analysis/analysis.h"
+#include "analysis/walkitem.h"
+
+#include "nodes/expr/eq_expr.h"
+#include "nodes/expr/indirect_ref.h"
+#include "nodes/expr/modify_expr.h"
+#include "nodes/expr/pointerplus_expr.h"
+
+#include "nodes/stmt/if_stmt.h"
+
+#include <set>
+
+#include "localconsts.h"
+
+namespace Analysis
+{
+
+WalkItem analyseIfStmt(IfStmtNode *node, WalkItem wi)
+{
+    // need condition node
+    if (!node->condition || command == FindArgs)
+        return wi;
+
+    if (node->condition->nodeType == EQ_EXPR)
+    {
+        EqExprNode *eq = static_cast<EqExprNode*>(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
+            walkTree(node->thenNode, wi);
+            // From else branch remove variable what we just found.
+            wi.checkNullVars.erase(node1->label);
+            walkTree(node->elseNode, wi);
+            wi.stopWalking = true;
+
+            // need aslo on parent remove variable too
+            // probably wi should have pointer to parent
+            return wi;
+        }
+    }
+
+    return wi;
+}
+
+}
diff --git a/src/analysis/statement.h b/src/analysis/statement.h
new file mode 100644
index 0000000..5672e7f
--- /dev/null
+++ b/src/analysis/statement.h
@@ -0,0 +1,33 @@
+/*
+ *  Copyright (C) 2015  Andrei Karas
+ *
+ *  This file is part of AstDumper.
+ *
+ *  This program is free software; you can redistribute it and/or modify
+ *  it under the terms of the GNU General Public License as published by
+ *  the Free Software Foundation; either version 3 of the License, or
+ *  any later version.
+ *
+ *  This program is distributed in the hope that it will be useful,
+ *  but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ *  GNU General Public License for more details.
+ *
+ *  You should have received a copy of the GNU General Public License
+ *  along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#ifndef ANALYSIS_STATEMENT_H
+#define ANALYSIS_STATEMENT_H
+
+#include "includes.h"
+
+struct IfStmtNode;
+struct WalkItem;
+
+namespace Analysis
+{
+    WalkItem analyseIfStmt(IfStmtNode *node, WalkItem wi);
+}
+
+#endif // ANALYSIS_STATEMENT_H
-- 
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