/*
* Copyright (C) 2015 Andrei Karas
*
* This file is part of Paranoid null checker.
*
* 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 .
*/
#include "analysis/expression.h"
#include "command.h"
#include "logger.h"
#include "analysis/analysis.h"
#include "analysis/statement.h"
#include "analysis/walkitem.h"
#include "nodes/expr/addr_expr.h"
#include "nodes/expr/bind_expr.h"
#include "nodes/expr/call_expr.h"
#include "nodes/expr/cleanuppoint_expr.h"
#include "nodes/expr/compound_expr.h"
#include "nodes/expr/cond_expr.h"
#include "nodes/expr/decl_expr.h"
#include "nodes/expr/eq_expr.h"
#include "nodes/expr/init_expr.h"
#include "nodes/expr/modify_expr.h"
#include "nodes/expr/ne_expr.h"
#include "nodes/expr/nonlvalue_expr.h"
#include "nodes/expr/nop_expr.h"
#include "nodes/expr/pointerplus_expr.h"
#include "nodes/expr/return_expr.h"
#include "nodes/expr/truthand_expr.h"
#include "nodes/expr/truthandif_expr.h"
#include "nodes/expr/truthor_expr.h"
#include "nodes/expr/truthorif_expr.h"
#include "nodes/decl/function_decl.h"
#include "nodes/decl/var_decl.h"
#include "nodes/ref/component_ref.h"
#include "nodes/ref/indirect_ref.h"
#include
#include "localconsts.h"
namespace Analysis
{
// return variable name if possible or empty string
std::string getVariableName(Node *node)
{
if (!node)
return "";
node = skipNop(node);
if (!node)
return "";
if (node == PARM_DECL || node == VAR_DECL)
return node->label;
else if (node == COMPONENT_REF)
return getComponentRefVariable(node);
return "";
}
// return variable name in format object->field for component node
std::string getComponentRefVariable(Node *node)
{
std::string str;
ComponentRefNode *const comp = static_cast(skipNop(node));
if (comp->object &&
comp->field)
{
Node *object = skipNop(comp->object);
Node *field = skipNop(comp->field);
if (object == INDIRECT_REF &&
field == FIELD_DECL)
{
IndirectRefNode *indirect = static_cast(object);
Node *ref = skipNop(indirect->ref);
if (ref == PARM_DECL)
{
str.append(ref->label).append("->").append(field->label);
}
}
}
return str;
}
void analyseModifyExpr(ModifyExprNode *node, const WalkItem &wi, WalkItem &wo)
{
// need atleast one arg for check
if (node->args.empty() || command == FindArgs)
return;
Node *arg = skipNop(node->args[0]);
if (arg)
{
if (arg == INDIRECT_REF)
{
reportParmDeclNullPointer(node,
static_cast(arg)->ref,
wi);
}
else if (arg == COMPONENT_REF && node->args.size() > 1)
{
std::string var1 = getComponentRefVariable(arg);
std::string var2 = getVariableName(node->args[1]);
if (!var1.empty() && !var2.empty())
{
wo.addNullVars.insert(var1);
addLinkedVar(wo, var2, var1);
}
}
}
}
void analysePointerPlusExpr(PointerPlusExprNode *node,
const WalkItem &wi,
WalkItem &wo A_UNUSED)
{
// need atleast one arg for check
if (node->args.empty() || command == FindArgs)
return;
reportParmDeclNullPointer(node, node->args[0], wi);
}
void analyseAddrExpr(AddrExprNode *node,
const WalkItem &wi,
WalkItem &wo A_UNUSED)
{
// need atleast one arg for check
if (node->args.empty() || command == FindArgs)
return;
// do not report code like func1(ptr) or push_back(ptr)
Node *node2 = skipBackNop(node->parent);
if (node2)
{
while (node2 == ADDR_EXPR)
{
node2 = skipBackNop(node2->parent);
}
// found what some parent is function or method call
if (node2 == CALL_EXPR)
{
return;
}
}
reportParmDeclNullPointer(node, node->args[0], wi);
}
void analyseReturnExpr(ReturnExprNode *node A_UNUSED,
const WalkItem &wi A_UNUSED,
WalkItem &wo)
{
wo.isReturned = true;
}
void analyseNeExpr(NeExprNode *node, const WalkItem &wi, WalkItem &wo)
{
// need two args for check
if (node->args.size() < 2 || command == FindArgs)
return;
// PARM_DECL or VAR_DECL?
Node *node1 = skipNop(node->args[0]);
// INTEGER_CST?
Node *node2 = skipNop(node->args[1]);
std::string var = getVariableName(node1);
// if (var != 0)
if (!var.empty() &&
node2 == INTEGER_CST &&
wi.checkNullVars.find(var) != wi.checkNullVars.end() &&
node2->label == "0")
{
wo.checkedNonNullVars.insert(var);
wo.cleanExpr = true;
wo.uselessExpr = false;
}
else
{
wo.cleanExpr = false;
wo.uselessExpr = true;
}
}
void analyseEqExpr(EqExprNode *node, const WalkItem &wi, WalkItem &wo)
{
// need two args for check
if (node->args.size() < 2 || command == FindArgs)
return;
// PARM_DECL or VAR_DECL ?
Node *node1 = skipNop(node->args[0]);
// INTEGER_CST?
Node *node2 = skipNop(node->args[1]);
std::string var = getVariableName(node1);
// if (var == 0)
if (!var.empty() &&
node2 == INTEGER_CST &&
wi.checkNullVars.find(var) != wi.checkNullVars.end() &&
node2->label == "0")
{
wo.checkedNullVars.insert(var);
wo.cleanExpr = true;
wo.uselessExpr = false;
}
else
{
wo.cleanExpr = false;
wo.uselessExpr = true;
}
}
void analyseOrCondition(Node *node, Node *node1, Node *node2, const WalkItem &wi, WalkItem &wo)
{
WalkItem wo1 = wo;
WalkItem wo2 = wo;
walkTree(node1, wi, wo1);
Log::dumpWI(node, "wo1 ", wo1);
WalkItem wi2 = wi;
removeCheckNullVarsSet(wi2, wo1.checkedNullVars);
wi2.checkNullVars.insert(wo1.checkedNonNullVars.begin(),
wo1.checkedNonNullVars.end());
Log::dumpWI(node, "wi2 ", wi2);
walkTree(node2, wi2, wo2);
Log::dumpWI(node, "wo2 ", wo2);
// probably condition wrong
if (wo1.cleanExpr)
mergeNullChecked(wo, wo1);
// probably condition wrong
if (wo2.cleanExpr)
mergeNullChecked(wo, wo2);
// need check for cleanExpr?
intersectNonNullChecked(wo, wo1, wo2);
wo.cleanExpr = true;
wo.stopWalking = true;
wo.uselessExpr = false;
}
void analyseAndCondition(Node *node, Node *node1, Node *node2, const WalkItem &wi, WalkItem &wo)
{
WalkItem wo1 = wo;
WalkItem wo2 = wo;
walkTree(node1, wi, wo1);
Log::dumpWI(node, "wo1 ", wo1);
WalkItem wi2 = wi;
removeCheckNullVarsSet(wi2, wo1.checkedNonNullVars);
wi2.checkNullVars.insert(wo1.checkedNullVars.begin(),
wo1.checkedNullVars.end());
Log::dumpWI(node, "wi2 ", wi2);
walkTree(node2, wi2, wo2);
Log::dumpWI(node, "wo2 ", wo2);
wo.stopWalking = true;
// probably condition wrong
if (!wo1.uselessExpr && !wo2.uselessExpr)
{ // need combine wo1 and wo2
intersectNullChecked(wo, wo1, wo2);
}
if (!wo1.uselessExpr)
{
mergeNonNullChecked(wo, wo1);
}
if (!wo2.uselessExpr)
{
mergeNonNullChecked(wo, wo2);
}
wo.cleanExpr = wo1.cleanExpr && wo2.cleanExpr;
wo.uselessExpr = wo1.uselessExpr && wo2.uselessExpr;
}
void analyseTruthOrIfExpr(TruthOrIfExprNode *node, const WalkItem &wi, WalkItem &wo)
{
// need two args for check
if (node->args.size() < 2 || command == FindArgs)
return;
analyseOrCondition(node, node->args[0], node->args[1], wi, wo);
}
void analyseTruthOrExpr(TruthOrExprNode *node, const WalkItem &wi, WalkItem &wo)
{
// need two args for check
if (node->args.size() < 2 || command == FindArgs)
return;
analyseOrCondition(node, node->args[0], node->args[1], wi, wo);
}
void analyseTruthAndIfExpr(TruthAndIfExprNode *node, const WalkItem &wi, WalkItem &wo)
{
// need two args for check
if (node->args.size() < 2 || command == FindArgs)
return;
analyseAndCondition(node, node->args[0], node->args[1], wi, wo);
}
void analyseTruthAndExpr(TruthAndExprNode *node, const WalkItem &wi, WalkItem &wo)
{
// need two args for check
if (node->args.size() < 2 || command == FindArgs)
return;
analyseAndCondition(node, node->args[0], node->args[1], wi, wo);
}
// args[0] condition
// args[1] true expr
// args[2] false expr
void analyseCondExpr(CondExprNode *node, const WalkItem &wi, WalkItem &wo)
{
// need tree args for check
if (node->args.size() < 3 || command == FindArgs)
return;
analyseCondition(node,
node->args[0],
node->args[1],
node->args[2],
wi,
wo);
}
// expression like this (expr1, expr2, ..., exprn). Only have sense exprn.
void analyseCompoundExpr(CompoundExprNode *node, const WalkItem &wi, WalkItem &wo)
{
// need one arg for check
if (node->args.size() < 1 || command == FindArgs)
return;
const size_t sz = node->args.size();
// walking and ignoring results for all args except last
for (size_t f = 0; f < sz - 1; f ++)
{
WalkItem wo1 = wo;
walkTree(node->args[f], wi, wo1);
Log::dumpWI(node, "wo1 ", wo1);
}
WalkItem wo2 = wo;
walkTree(node->args[sz - 1], wi, wo2);
Log::dumpWI(node, "wo2 ", wo2);
// probably condition wrong
if (wo2.cleanExpr)
{
mergeNullChecked(wo, wo2);
mergeNonNullChecked(wo, wo2);
}
//wo.removeNullVars.clear();
wo.cleanExpr = true;
wo.stopWalking = true;
wo.uselessExpr = false;
}
// type var1 = var2;
void analyseBindExpr(BindExprNode *node, const WalkItem &wi, WalkItem &wo)
{
const size_t sz = node->args.size();
if (sz < 1 || command == FindArgs)
return;
WalkItem wi2 = wi;
walkTree(node->args[1], wi2, wo);
wi2 = wo;
Log::dumpWI(node, "wi2 ", wi2);
walkTree(node->args[0], wi2, wo);
if (sz > 2)
{
wi2 = wo;
Log::dumpWI(node, "wi2 ", wi2);
walkTree(node->args[2], wi2, wo);
}
Node *node1 = skipNop(node->args[0]);
if (node1 == VAR_DECL)
{
VarDeclNode *varDecl = static_cast(node1);
Node *initial = skipNop(varDecl->initial);
if (checkForReport(initial, wi))
{
wo.addNullVars.insert(varDecl->label);
addLinkedVar(wo, initial->label, varDecl->label);
}
}
wo.stopWalking = true;
}
// type var1 = var2;
void analyseDeclExpr(DeclExprNode *node, const WalkItem &wi, WalkItem &wo)
{
// need one arg for check
if (node->args.empty() || command == FindArgs)
return;
Node *node1 = skipNop(node->args[0]);
if (node1 == VAR_DECL)
{
VarDeclNode *varDecl = static_cast(node1);
Node *initial = skipNop(varDecl->initial);
if (checkForReport(initial, wi))
{
wo.addNullVars.insert(varDecl->label);
addLinkedVar(wo, initial->label, varDecl->label);
}
}
}
void analyseNopExpr(NopExprNode *node, const WalkItem &wi, WalkItem &wo)
{
// need one arg for check
if (node->args.empty())
return;
walkTree(node->args[0], wi, wo);
wo.stopWalking = true;
}
void analyseNonLvalueExpr(NonLvalueExprNode *node, const WalkItem &wi, WalkItem &wo)
{
// need one arg for check
if (node->args.empty())
return;
walkTree(node->args[0], wi, wo);
wo.stopWalking = true;
}
void analyseCallExpr(CallExprNode *node, const WalkItem &wi, WalkItem &wo)
{
WalkItem wo2 = wo;
walkTree(node->chain, wi, wo2);
Log::dumpWI(node, "wo chain ", wo2);
wo2 = wo;
bool enableCheck(true);
if (node->function)
{
walkTree(node->function, wi, wo2);
Log::dumpWI(node, "wo function ", wo2);
if (node->function == ADDR_EXPR)
{
AddrExprNode *addrNode = static_cast(node->function);
if (!addrNode->args.empty())
{
if (addrNode->args[0] == FUNCTION_DECL)
{
FunctionDeclNode *declNode = static_cast(
addrNode->args[0]);
if (declNode->functionType == FUNCTION_TYPE)
{
enableCheck = false;
}
}
}
}
}
FOR_EACH (std::vector::const_iterator, it, node->args)
{
wo2 = wo;
Node *node2 = skipNop(*it);
if (enableCheck)
{
reportParmDeclNullPointer(node, node2, wi);
enableCheck = false;
}
walkTree(node2, wi, wo2);
Log::dumpWI(node, "wo arg ", wo2);
}
wo.stopWalking = true;
}
void analyseCleanupPointExpr(CleanupPointExprNode* node, const WalkItem &wi, WalkItem &wo)
{
WalkItem wo2 = wo;
FOR_EACH (std::vector::const_iterator, it, node->args)
{
wo2 = wo;
Node *node2 = skipNop(*it);
reportParmDeclNullPointer(node, node2, wi);
walkTree(node2, wi, wo2);
Log::dumpWI(node, "wo arg ", wo2);
}
wo = wo2;
wo.stopWalking = true;
}
void analyseInitExpr(InitExprNode* node,
const WalkItem &wi A_UNUSED,
WalkItem &wo)
{
// need one arg for check
if (node->args.size() < 2 || command == FindArgs)
return;
// var1 = var2
std::string var1 = getVariableName(node->args[0]);
std::string var2 = getVariableName(node->args[1]);
if (var1.empty() || var2.empty())
return;
wo.addNullVars.insert(var1);
addLinkedVar(wo, var2, var1);
}
}