360 lines
13 KiB
C++
360 lines
13 KiB
C++
/*
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* Cppcheck - A tool for static C/C++ code analysis
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* Copyright (C) 2007-2015 Daniel Marjamäki and Cppcheck team.
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*
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* This program is free software: you can redistribute it and/or modify
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* it under the terms of the GNU General Public License as published by
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* the Free Software Foundation, either version 3 of the License, or
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* (at your option) any later version.
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*
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* This program is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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* GNU General Public License for more details.
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*
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* You should have received a copy of the GNU General Public License
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* along with this program. If not, see <http://www.gnu.org/licenses/>.
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*/
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//---------------------------------------------------------------------------
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#include "astutils.h"
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#include "symboldatabase.h"
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#include "token.h"
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#include "tokenize.h"
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#include <set>
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static bool isChar(const Variable* var)
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{
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return (var && !var->isPointer() && !var->isArray() && var->typeStartToken()->str() == "char");
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}
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static bool isSignedChar(const Variable* var)
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{
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return (isChar(var) && !var->typeStartToken()->isUnsigned());
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}
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bool astIsSignedChar(const Token *tok)
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{
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if (!tok)
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return false;
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if (tok->str() == "*" && tok->astOperand1() && !tok->astOperand2()) {
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const Variable *var = tok->astOperand1()->variable();
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if (!var || !var->isPointer())
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return false;
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const Token *type = var->typeStartToken();
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while (type && type->str() == "const")
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type = type->next();
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return (type && type->str() == "char" && !type->isUnsigned());
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}
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return isSignedChar(tok->variable());
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}
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bool astIsIntegral(const Token *tok, bool unknown)
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{
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// TODO: handle arrays
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if (tok->isNumber())
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return MathLib::isInt(tok->str());
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if (tok->isName()) {
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if (tok->variable())
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return tok->variable()->isIntegralType();
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return unknown;
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}
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if (tok->str() == "(") {
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// cast
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if (Token::Match(tok, "( const| float|double )"))
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return false;
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// Function call
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if (tok->previous()->function()) {
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if (Token::Match(tok->previous()->function()->retDef, "float|double"))
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return false;
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else if (Token::Match(tok->previous()->function()->retDef, "bool|char|short|int|long"))
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return true;
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}
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if (tok->strAt(-1) == "sizeof")
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return true;
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return unknown;
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}
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if (tok->astOperand2() && (tok->str() == "." || tok->str() == "::"))
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return astIsIntegral(tok->astOperand2(), unknown);
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if (tok->astOperand1() && tok->str() != "?")
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return astIsIntegral(tok->astOperand1(), unknown);
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return unknown;
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}
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bool astIsFloat(const Token *tok, bool unknown)
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{
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// TODO: handle arrays
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if (tok->isNumber())
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return MathLib::isFloat(tok->str());
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if (tok->isName()) {
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if (tok->variable())
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return tok->variable()->isFloatingType();
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return unknown;
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}
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if (tok->str() == "(") {
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// cast
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if (Token::Match(tok, "( const| float|double )"))
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return true;
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// Function call
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if (tok->previous()->function())
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return Token::Match(tok->previous()->function()->retDef, "float|double");
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if (tok->strAt(-1) == "sizeof")
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return false;
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return unknown;
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}
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if (tok->astOperand2() && (tok->str() == "." || tok->str() == "::"))
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return astIsFloat(tok->astOperand2(), unknown);
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if (tok->astOperand1() && tok->str() != "?" && astIsFloat(tok->astOperand1(), unknown))
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return true;
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if (tok->astOperand2() && astIsFloat(tok->astOperand2(), unknown))
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return true;
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if (tok->isOp())
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return false;
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return unknown;
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}
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std::string astCanonicalType(const Token *expr)
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{
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if (!expr)
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return "";
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if (expr->variable()) {
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const Variable *var = expr->variable();
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std::string ret;
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for (const Token *type = var->typeStartToken(); Token::Match(type,"%name%|::") && type != var->nameToken(); type = type->next()) {
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if (!Token::Match(type, "const|static"))
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ret += type->str();
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}
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return ret;
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}
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// TODO: handle expressions
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return "";
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}
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const Token * astIsVariableComparison(const Token *tok, const std::string &comp, const std::string &rhs, const Token **vartok)
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{
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if (!tok)
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return nullptr;
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const Token *ret = nullptr;
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if (tok->isComparisonOp()) {
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if (tok->astOperand1() && tok->astOperand1()->str() == rhs) {
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// Invert comparator
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std::string s = tok->str();
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if (s[0] == '>')
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s[0] = '<';
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else if (s[0] == '<')
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s[0] = '>';
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if (s == comp) {
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ret = tok->astOperand2();
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}
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} else if (tok->str() == comp && tok->astOperand2() && tok->astOperand2()->str() == rhs) {
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ret = tok->astOperand1();
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}
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} else if (comp == "!=" && rhs == std::string("0")) {
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ret = tok;
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} else if (comp == "==" && rhs == std::string("0")) {
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if (tok->str() == "!")
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ret = tok->astOperand1();
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}
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while (ret && ret->str() == ".")
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ret = ret->astOperand2();
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if (ret && ret->varId() == 0U)
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ret = nullptr;
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if (vartok)
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*vartok = ret;
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return ret;
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}
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bool isSameExpression(bool cpp, const Token *tok1, const Token *tok2, const std::set<std::string> &constFunctions)
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{
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if (tok1 == nullptr && tok2 == nullptr)
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return true;
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if (tok1 == nullptr || tok2 == nullptr)
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return false;
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if (cpp) {
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if (tok1->str() == "." && tok1->astOperand1() && tok1->astOperand1()->str() == "this")
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tok1 = tok1->astOperand2();
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if (tok2->str() == "." && tok2->astOperand1() && tok2->astOperand1()->str() == "this")
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tok2 = tok2->astOperand2();
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}
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if (tok1->varId() != tok2->varId() || tok1->str() != tok2->str()) {
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if ((Token::Match(tok1,"<|>") && Token::Match(tok2,"<|>")) ||
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(Token::Match(tok1,"<=|>=") && Token::Match(tok2,"<=|>="))) {
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return isSameExpression(cpp, tok1->astOperand1(), tok2->astOperand2(), constFunctions) &&
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isSameExpression(cpp, tok1->astOperand2(), tok2->astOperand1(), constFunctions);
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}
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return false;
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}
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if (tok1->str() == "." && tok1->originalName() != tok2->originalName())
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return false;
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if (tok1->isExpandedMacro() || tok2->isExpandedMacro())
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return false;
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if (tok1->isName() && tok1->next()->str() == "(" && tok1->str() != "sizeof") {
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if (!tok1->function() && !Token::Match(tok1->previous(), ".|::") && constFunctions.find(tok1->str()) == constFunctions.end() && !tok1->isAttributeConst() && !tok1->isAttributePure())
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return false;
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else if (tok1->function() && !tok1->function()->isConst() && !tok1->function()->isAttributeConst() && !tok1->function()->isAttributePure())
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return false;
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}
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// templates/casts
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if ((Token::Match(tok1, "%name% <") && tok1->next()->link()) ||
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(Token::Match(tok2, "%name% <") && tok2->next()->link())) {
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// non-const template function that is not a dynamic_cast => return false
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if (Token::simpleMatch(tok1->next()->link(), "> (") &&
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!(tok1->function() && tok1->function()->isConst()) &&
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tok1->str() != "dynamic_cast")
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return false;
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// some template/cast stuff.. check that the template arguments are same
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const Token *t1 = tok1->next();
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const Token *t2 = tok2->next();
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const Token *end1 = t1->link();
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const Token *end2 = t2->link();
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while (t1 && t2 && t1 != end1 && t2 != end2) {
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if (t1->str() != t2->str())
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return false;
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t1 = t1->next();
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t2 = t2->next();
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}
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if (t1 != end1 || t2 != end2)
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return false;
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}
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if (tok1->tokType() == Token::eIncDecOp || tok1->isAssignmentOp())
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return false;
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// bailout when we see ({..})
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if (tok1->str() == "{")
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return false;
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if (tok1->str() == "(" && tok1->previous() && !tok1->previous()->isName()) { // cast => assert that the casts are equal
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const Token *t1 = tok1->next();
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const Token *t2 = tok2->next();
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while (t1 && t2 && t1->str() == t2->str() && (t1->isName() || t1->str() == "*")) {
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t1 = t1->next();
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t2 = t2->next();
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}
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if (!t1 || !t2 || t1->str() != ")" || t2->str() != ")")
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return false;
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}
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bool noncommuative_equals =
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isSameExpression(cpp, tok1->astOperand1(), tok2->astOperand1(), constFunctions);
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noncommuative_equals = noncommuative_equals &&
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isSameExpression(cpp, tok1->astOperand2(), tok2->astOperand2(), constFunctions);
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if (noncommuative_equals)
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return true;
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const bool commutative = tok1->astOperand1() && tok1->astOperand2() && Token::Match(tok1, "%or%|%oror%|+|*|&|&&|^|==|!=");
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bool commuative_equals = commutative &&
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isSameExpression(cpp, tok1->astOperand2(), tok2->astOperand1(), constFunctions);
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commuative_equals = commuative_equals &&
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isSameExpression(cpp, tok1->astOperand1(), tok2->astOperand2(), constFunctions);
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// in c++, "a"+b might be different to b+"a"
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if (cpp && commuative_equals && tok1->str() == "+" &&
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(tok1->astOperand1()->tokType() == Token::eString || tok1->astOperand2()->tokType() == Token::eString)) {
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const Token * const other = tok1->astOperand1()->tokType() != Token::eString ? tok1->astOperand1() : tok1->astOperand2();
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return other && astIsIntegral(other,false);
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}
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return commuative_equals;
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}
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bool isOppositeCond(bool isNot, bool cpp, const Token * const cond1, const Token * const cond2, const std::set<std::string> &constFunctions)
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{
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if (!cond1 || !cond2)
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return false;
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if (cond1->str() == "!") {
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if (cond2->str() == "!=") {
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if (cond2->astOperand1() && cond2->astOperand1()->str() == "0")
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return isSameExpression(cpp, cond1->astOperand1(), cond2->astOperand2(), constFunctions);
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if (cond2->astOperand2() && cond2->astOperand2()->str() == "0")
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return isSameExpression(cpp, cond1->astOperand1(), cond2->astOperand1(), constFunctions);
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}
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return isSameExpression(cpp, cond1->astOperand1(), cond2, constFunctions);
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}
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if (cond2->str() == "!")
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return isOppositeCond(isNot, cpp, cond2, cond1, constFunctions);
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if (!cond1->isComparisonOp() || !cond2->isComparisonOp())
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return false;
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const std::string &comp1 = cond1->str();
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// condition found .. get comparator
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std::string comp2;
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if (isSameExpression(cpp, cond1->astOperand1(), cond2->astOperand1(), constFunctions) &&
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isSameExpression(cpp, cond1->astOperand2(), cond2->astOperand2(), constFunctions)) {
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comp2 = cond2->str();
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} else if (isSameExpression(cpp, cond1->astOperand1(), cond2->astOperand2(), constFunctions) &&
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isSameExpression(cpp, cond1->astOperand2(), cond2->astOperand1(), constFunctions)) {
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comp2 = cond2->str();
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if (comp2[0] == '>')
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comp2[0] = '<';
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else if (comp2[0] == '<')
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comp2[0] = '>';
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}
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// is condition opposite?
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return ((comp1 == "==" && comp2 == "!=") ||
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(comp1 == "!=" && comp2 == "==") ||
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(comp1 == "<" && comp2 == ">=") ||
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(comp1 == "<=" && comp2 == ">") ||
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(comp1 == ">" && comp2 == "<=") ||
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(comp1 == ">=" && comp2 == "<") ||
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(!isNot && ((comp1 == "<" && comp2 == ">") ||
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(comp1 == ">" && comp2 == "<"))));
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}
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bool isConstExpression(const Token *tok, const std::set<std::string> &constFunctions)
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{
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if (!tok)
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return true;
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if (tok->isName() && tok->next()->str() == "(") {
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if (!tok->function() && !Token::Match(tok->previous(), ".|::") && constFunctions.find(tok->str()) == constFunctions.end())
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return false;
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else if (tok->function() && !tok->function()->isConst())
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return false;
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}
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if (tok->tokType() == Token::eIncDecOp)
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return false;
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// bailout when we see ({..})
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if (tok->str() == "{")
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return false;
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return isConstExpression(tok->astOperand1(),constFunctions) && isConstExpression(tok->astOperand2(),constFunctions);
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}
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bool isWithoutSideEffects(bool cpp, const Token* tok)
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{
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if (!cpp)
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return true;
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while (tok && tok->astOperand2() && tok->astOperand2()->str() != "(")
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tok = tok->astOperand2();
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if (tok && tok->varId()) {
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const Variable* var = tok->variable();
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return var && (!var->isClass() || var->isPointer() || var->isStlType());
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}
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return true;
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}
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