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/*
* 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/modify_expr.h"
#include "nodes/expr/ne_expr.h"
#include "nodes/expr/pointerplus_expr.h"
#include "nodes/ref/indirect_ref.h"
#include "nodes/stmt/if_stmt.h"
#include <set>
#include "localconsts.h"
namespace Analysis
{
void analyseIfStmt(IfStmtNode *node, const WalkItem &wi, WalkItem &wo)
{
// need condition node
if (!node->condition || command == FindArgs)
return;
Node *condNode = skipNop(node->condition);
if (condNode->nodeType == EQ_EXPR)
{ // if (... == ..)
EqExprNode *eq = static_cast<EqExprNode*>(condNode);
// need atleast two operands for EQ_EXPR node
if (eq->args.size() < 2)
return;
// PARM_DECL?
Node *node1 = skipNop(eq->args[0]);
// INTEGER_CST?
Node *node2 = skipNop(eq->args[1]);
// if (var == 0)
if (node1 &&
node2 &&
node1->nodeType == PARM_DECL &&
node2->nodeType == INTEGER_CST &&
wi.checkNullVars.find(node1->label) != wi.checkNullVars.end() &&
node2->label == "0")
{
WalkItem wi2 = wi;
// found check for parameter and 0.
// walking to then branch
walkTree(node->thenNode, wi2, wo);
wo.removeNullVars.clear();
const bool returned = wo.isReturned;
// if (wo.isReturned)
// Log::log("wo.isReturned 1\n");
// 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;
// if (wo.isReturned)
// Log::log("wo.isReturned 2\n");
wo.isReturned = false;
if (returned)
{
//Log::log("add removeNullVars: %s\n", node1->label.c_str());
// add variable for ignore for all parent nodes except special like IF_STMT
wo.removeNullVars.insert(node1->label);
wo.checkNullVars.erase(node1->label);
}
return;
}
}
else if (condNode->nodeType == NE_EXPR)
{ // if (... != ..)
NeExprNode *ne = static_cast<NeExprNode*>(condNode);
// need atleast two operands for NE_EXPR node
if (ne->args.size() < 2)
return;
// PARM_DECL?
Node *node1 = skipNop(ne->args[0]);
// INTEGER_CST?
Node *node2 = skipNop(ne->args[1]);
// if (var != 0)
if (node1 &&
node2 &&
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, wo);
// if (wo.isReturned)
// Log::log("wo.isReturned 3\n");
wo.removeNullVars.clear();
wi2 = wi;
// walking else node with all variables
walkTree(node->elseNode, wi2, wo);
// if (wo.isReturned)
// Log::log("wo.isReturned 4\n");
wo.removeNullVars.clear();
wo.stopWalking = true;
if (wo.isReturned && node->elseNode)
{
//Log::log("add removeNullVars: %s\n", node1->label.c_str());
// add variable for ignore for all parent nodes except special like IF_STMT
wo.removeNullVars.insert(node1->label);
wo.checkNullVars.erase(node1->label);
}
wo.isReturned = false;
return;
}
}
// default case
walkTree(node->thenNode, wi, wo);
walkTree(node->elseNode, wi, wo);
wo.removeNullVars.clear();
// if (wo.isReturned)
// Log::log("wo.isReturned 5\n");
wo.isReturned = false;
wo.stopWalking = true;
}
}
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