cppcheck/lib/valueflow.cpp

120 lines
4.7 KiB
C++

/*
* Cppcheck - A tool for static C/C++ code analysis
* Copyright (C) 2007-2013 Daniel Marjamäki and Cppcheck team.
*
* 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
* (at your option) 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 "valueflow.h"
#include "errorlogger.h"
#include "mathlib.h"
#include "settings.h"
#include "symboldatabase.h"
#include "token.h"
#include "tokenlist.h"
static void bailout(TokenList *tokenlist, ErrorLogger *errorLogger, const Token *tok, const std::string &what)
{
std::list<ErrorLogger::ErrorMessage::FileLocation> callstack;
callstack.push_back(ErrorLogger::ErrorMessage::FileLocation(tok,tokenlist));
ErrorLogger::ErrorMessage errmsg(callstack, Severity::debug, "ValueFlow bailout: " + what, "valueFlowBailout", false);
errorLogger->reportErr(errmsg);
}
static void valueFlowBeforeCondition(TokenList *tokenlist, ErrorLogger *errorLogger, const Settings *settings)
{
for (Token *tok = tokenlist->front(); tok; tok = tok->next()) {
unsigned int varid;
MathLib::bigint num;
const Variable *var;
if (Token::Match(tok, "==|!=|>=|<=") && tok->astOperand1() && tok->astOperand2()) {
if (tok->astOperand1()->isName() && tok->astOperand2()->isNumber()) {
varid = tok->astOperand1()->varId();
var = tok->astOperand1()->variable();
num = MathLib::toLongNumber(tok->astOperand2()->str());
} else if (tok->astOperand1()->isNumber() && tok->astOperand2()->isName()) {
varid = tok->astOperand2()->varId();
var = tok->astOperand2()->variable();
num = MathLib::toLongNumber(tok->astOperand1()->str());
} else {
continue;
}
} else if (Token::Match(tok->previous(), "if|while ( %var% %oror%|&&|)") ||
Token::Match(tok, "%oror%|&& %var% %oror%|&&|)")) {
varid = tok->next()->varId();
var = tok->next()->variable();
num = 0;
} else if (tok->str() == "!" && tok->astOperand1() && tok->astOperand1()->isName()) {
varid = tok->astOperand1()->varId();
var = tok->astOperand1()->variable();
num = 0;
} else {
continue;
}
if (varid == 0U)
continue;
// bailout: global variables
if (var && var->isGlobal()) {
if (settings->debugwarnings)
bailout(tokenlist, errorLogger, tok, "global variable " + var->nameToken()->str());
continue;
}
struct ValueFlow::Value val;
val.condition = tok;
val.intvalue = num;
for (Token *tok2 = tok->previous(); ; tok2 = tok2->previous()) {
if (!tok2) {
if (settings->debugwarnings) {
std::list<ErrorLogger::ErrorMessage::FileLocation> callstack;
callstack.push_back(ErrorLogger::ErrorMessage::FileLocation(tok,tokenlist));
ErrorLogger::ErrorMessage errmsg(callstack, Severity::debug, "iterated too far", "debugValueFlowBeforeCondition", false);
errorLogger->reportErr(errmsg);
}
break;
}
if (tok2->varId() == varid) {
// bailout: assignment
if (Token::Match(tok2, "%var% =")) {
if (settings->debugwarnings)
bailout(tokenlist, errorLogger, tok2, "assignment of " + tok2->str());
break;
}
tok2->values.push_back(val);
if (var && tok2 == var->nameToken())
break;
}
if (tok2->str() == "}") {
if (settings->debugwarnings)
bailout(tokenlist, errorLogger, tok2, "variable " + var->nameToken()->str() + " stopping on }");
break;
}
}
}
}
void ValueFlow::setValues(TokenList *tokenlist, ErrorLogger *errorLogger, const Settings *settings)
{
for (Token *tok = tokenlist->front(); tok; tok = tok->next())
tok->values.clear();
valueFlowBeforeCondition(tokenlist, errorLogger, settings);
}