Add basic analysis for IF_STMT.

1 files changed, 82 insertions, 0 deletions

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;
+}
+
+}