1548 lines
60 KiB
C++
1548 lines
60 KiB
C++
/*
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* Cppcheck - A tool for static C/C++ code analysis
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* Copyright (C) 2007-2019 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 "library.h"
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#include "mathlib.h"
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#include "settings.h"
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#include "symboldatabase.h"
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#include "token.h"
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#include "valueflow.h"
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#include <list>
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#include <stack>
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void visitAstNodes(const Token *ast, std::function<ChildrenToVisit(const Token *)> visitor)
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{
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std::stack<const Token *> tokens;
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tokens.push(ast);
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while (!tokens.empty()) {
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const Token *tok = tokens.top();
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tokens.pop();
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if (!tok)
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continue;
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ChildrenToVisit c = visitor(tok);
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if (c == ChildrenToVisit::done)
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break;
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if (c == ChildrenToVisit::op1 || c == ChildrenToVisit::op1_and_op2)
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tokens.push(tok->astOperand1());
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if (c == ChildrenToVisit::op2 || c == ChildrenToVisit::op1_and_op2)
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tokens.push(tok->astOperand2());
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}
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}
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static bool astIsCharWithSign(const Token *tok, ValueType::Sign sign)
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{
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if (!tok)
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return false;
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const ValueType *valueType = tok->valueType();
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if (!valueType)
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return false;
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return valueType->type == ValueType::Type::CHAR && valueType->pointer == 0U && valueType->sign == sign;
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}
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bool astIsSignedChar(const Token *tok)
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{
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return astIsCharWithSign(tok, ValueType::Sign::SIGNED);
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}
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bool astIsUnknownSignChar(const Token *tok)
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{
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return astIsCharWithSign(tok, ValueType::Sign::UNKNOWN_SIGN);
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}
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bool astIsIntegral(const Token *tok, bool unknown)
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{
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const ValueType *vt = tok ? tok->valueType() : nullptr;
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if (!vt)
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return unknown;
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return vt->isIntegral() && vt->pointer == 0U;
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}
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bool astIsFloat(const Token *tok, bool unknown)
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{
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const ValueType *vt = tok ? tok->valueType() : nullptr;
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if (!vt)
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return unknown;
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return vt->type >= ValueType::Type::FLOAT && vt->pointer == 0U;
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}
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bool astIsBool(const Token *tok)
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{
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return tok && (tok->isBoolean() || (tok->valueType() && tok->valueType()->type == ValueType::Type::BOOL && !tok->valueType()->pointer));
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}
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bool astIsPointer(const Token *tok)
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{
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return tok && tok->valueType() && tok->valueType()->pointer;
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}
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bool astIsIterator(const Token *tok)
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{
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return tok && tok->valueType() && tok->valueType()->type == ValueType::Type::ITERATOR;
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}
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bool astIsContainer(const Token *tok)
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{
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return tok && tok->valueType() && tok->valueType()->type == ValueType::Type::CONTAINER;
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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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static bool match(const Token *tok, const std::string &rhs)
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{
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if (tok->str() == rhs)
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return true;
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if (!tok->varId() && tok->hasKnownIntValue() && MathLib::toString(tok->values().front().intvalue) == rhs)
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return true;
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return false;
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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() && match(tok->astOperand1(), 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() && match(tok->astOperand2(), 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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// handle (!(x!=0)) as (x==0)
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astIsVariableComparison(ret, "!=", "0", &ret);
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}
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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->str() == "=" && ret->astOperand1() && ret->astOperand1()->varId())
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ret = ret->astOperand1();
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else 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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static bool hasToken(const Token * startTok, const Token * stopTok, const Token * tok)
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{
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for (const Token * tok2 = startTok; tok2 != stopTok; tok2 = tok2->next()) {
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if (tok2 == tok)
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return true;
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}
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return false;
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}
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const Token * nextAfterAstRightmostLeaf(const Token * tok)
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{
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const Token * rightmostLeaf = tok;
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if (!rightmostLeaf || !rightmostLeaf->astOperand1())
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return nullptr;
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do {
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if (rightmostLeaf->astOperand2())
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rightmostLeaf = rightmostLeaf->astOperand2();
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else
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rightmostLeaf = rightmostLeaf->astOperand1();
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} while (rightmostLeaf->astOperand1());
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while (Token::Match(rightmostLeaf->next(), "]|)") && !hasToken(rightmostLeaf->next()->link(), rightmostLeaf->next(), tok))
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rightmostLeaf = rightmostLeaf->next();
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if (rightmostLeaf->str() == "{" && rightmostLeaf->link())
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rightmostLeaf = rightmostLeaf->link();
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return rightmostLeaf->next();
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}
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static const Token * getVariableInitExpression(const Variable * var)
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{
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if (!var || !var->declEndToken())
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return nullptr;
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if (Token::Match(var->declEndToken(), "; %varid% =", var->declarationId()))
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return var->declEndToken()->tokAt(2)->astOperand2();
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return var->declEndToken()->astOperand2();
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}
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static bool isInLoopCondition(const Token * tok)
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{
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return Token::Match(tok->astTop()->previous(), "for|while (");
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}
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/// If tok2 comes after tok1
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bool precedes(const Token * tok1, const Token * tok2)
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{
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if (!tok1)
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return false;
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if (!tok2)
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return false;
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return tok1->progressValue() < tok2->progressValue();
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}
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static bool isAliased(const Token * startTok, const Token * endTok, unsigned int varid)
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{
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for (const Token *tok = startTok; tok != endTok; tok = tok->next()) {
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if (Token::Match(tok, "= & %varid% ;", varid))
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return true;
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if (tok->varId() == varid)
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continue;
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if (tok->varId() == 0)
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continue;
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if (!astIsPointer(tok))
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continue;
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for (const ValueFlow::Value &val : tok->values()) {
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if (!val.isLocalLifetimeValue())
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continue;
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if (val.tokvalue->varId() == varid)
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return true;
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}
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}
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return false;
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}
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static bool exprDependsOnThis(const Token *expr, unsigned int depth)
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{
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if (!expr)
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return false;
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if (depth >= 1000)
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// Abort recursion to avoid stack overflow
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return true;
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++depth;
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// calling nonstatic method?
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if (Token::Match(expr->previous(), "!!:: %name% (") && expr->function() && expr->function()->nestedIn && expr->function()->nestedIn->isClassOrStruct()) {
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// is it a method of this?
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const Scope *nestedIn = expr->scope()->functionOf;
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if (nestedIn && nestedIn->function)
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nestedIn = nestedIn->function->token->scope();
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while (nestedIn && nestedIn != expr->function()->nestedIn) {
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nestedIn = nestedIn->nestedIn;
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}
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return nestedIn == expr->function()->nestedIn;
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}
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return exprDependsOnThis(expr->astOperand1(), depth) || exprDependsOnThis(expr->astOperand2(), depth);
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}
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/// This takes a token that refers to a variable and it will return the token
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/// to the expression that the variable is assigned to. If its not valid to
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/// make such substitution then it will return the original token.
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static const Token * followVariableExpression(const Token * tok, bool cpp, const Token * end = nullptr)
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{
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if (!tok)
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return tok;
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// Skip following variables that is across multiple files
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if (end && end->fileIndex() != tok->fileIndex())
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return tok;
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// Skip array access
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if (Token::Match(tok, "%var% ["))
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return tok;
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// Skip pointer indirection
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if (tok->astParent() && tok->isUnaryOp("*"))
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return tok;
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// Skip following variables if it is used in an assignment
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if (Token::Match(tok->next(), "%assign%"))
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return tok;
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const Variable * var = tok->variable();
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const Token * varTok = getVariableInitExpression(var);
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if (!varTok)
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return tok;
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// Bailout. If variable value depends on value of "this".
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if (exprDependsOnThis(varTok, 0))
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return tok;
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// Skip array access
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if (Token::simpleMatch(varTok, "["))
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return tok;
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if (var->isVolatile())
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return tok;
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if (!var->isLocal() && !var->isConst())
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return tok;
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if (var->isStatic() && !var->isConst())
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return tok;
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if (var->isArgument())
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return tok;
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const Token * lastTok = precedes(tok, end) ? end : tok;
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// If this is in a loop then check if variables are modified in the entire scope
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const Token * endToken = (isInLoopCondition(tok) || isInLoopCondition(varTok) || var->scope() != tok->scope()) ? var->scope()->bodyEnd : lastTok;
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if (!var->isConst() && (!precedes(varTok, endToken) || isVariableChanged(varTok, endToken, tok->varId(), false, nullptr, cpp)))
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return tok;
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if (precedes(varTok, endToken) && isAliased(varTok, endToken, tok->varId()))
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return tok;
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// Start at beginning of initialization
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const Token * startToken = varTok;
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while (Token::Match(startToken, "%op%|.|(|{") && startToken->astOperand1())
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startToken = startToken->astOperand1();
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// Skip if the variable its referring to is modified
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for (const Token * tok2 = startToken; tok2 != endToken; tok2 = tok2->next()) {
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if (Token::simpleMatch(tok2, ";"))
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break;
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if (tok2->astParent() && tok2->isUnaryOp("*"))
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return tok;
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if (tok2->tokType() == Token::eIncDecOp ||
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tok2->isAssignmentOp() ||
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Token::Match(tok2, "%name% .|[|++|--|%assign%")) {
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return tok;
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}
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if (const Variable * var2 = tok2->variable()) {
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if (!var2->scope())
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return tok;
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const Token * endToken2 = var2->scope() != tok->scope() ? var2->scope()->bodyEnd : endToken;
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if (!var2->isLocal() && !var2->isConst() && !var2->isArgument())
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return tok;
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if (var2->isStatic() && !var2->isConst())
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return tok;
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if (!var2->isConst() && (!precedes(tok2, endToken2) || isVariableChanged(tok2, endToken2, tok2->varId(), false, nullptr, cpp)))
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return tok;
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if (precedes(tok2, endToken2) && isAliased(tok2, endToken2, tok2->varId()))
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return tok;
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// Recognized as a variable but the declaration is unknown
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} else if (tok2->varId() > 0) {
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return tok;
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} else if (tok2->tokType() == Token::eName && !Token::Match(tok2, "sizeof|decltype|typeof") && !tok2->function()) {
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return tok;
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}
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}
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return varTok;
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}
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static void followVariableExpressionError(const Token *tok1, const Token *tok2, ErrorPath* errors)
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{
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if (!errors)
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return;
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if (!tok1)
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return;
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if (!tok2)
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return;
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ErrorPathItem item = std::make_pair(tok2, "'" + tok1->str() + "' is assigned value '" + tok2->expressionString() + "' here.");
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if (std::find(errors->begin(), errors->end(), item) != errors->end())
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return;
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errors->push_back(item);
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}
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bool isSameExpression(bool cpp, bool macro, const Token *tok1, const Token *tok2, const Library& library, bool pure, bool followVar, ErrorPath* errors)
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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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// Skip double not
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if (Token::simpleMatch(tok1, "!") && Token::simpleMatch(tok1->astOperand1(), "!") && !Token::simpleMatch(tok1->astParent(), "=")) {
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return isSameExpression(cpp, macro, tok1->astOperand1()->astOperand1(), tok2, library, pure, followVar, errors);
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}
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if (Token::simpleMatch(tok2, "!") && Token::simpleMatch(tok2->astOperand1(), "!") && !Token::simpleMatch(tok2->astParent(), "=")) {
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return isSameExpression(cpp, macro, tok1, tok2->astOperand1()->astOperand1(), library, pure, followVar, errors);
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}
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// Follow variable
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if (followVar && tok1->str() != tok2->str() && (Token::Match(tok1, "%var%") || Token::Match(tok2, "%var%"))) {
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const Token * varTok1 = followVariableExpression(tok1, cpp, tok2);
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if (varTok1->str() == tok2->str()) {
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followVariableExpressionError(tok1, varTok1, errors);
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return isSameExpression(cpp, macro, varTok1, tok2, library, true, followVar, errors);
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}
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const Token * varTok2 = followVariableExpression(tok2, cpp, tok1);
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if (tok1->str() == varTok2->str()) {
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followVariableExpressionError(tok2, varTok2, errors);
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return isSameExpression(cpp, macro, tok1, varTok2, library, true, followVar, errors);
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}
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if (varTok1->str() == varTok2->str()) {
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followVariableExpressionError(tok1, varTok1, errors);
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followVariableExpressionError(tok2, varTok2, errors);
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return isSameExpression(cpp, macro, varTok1, varTok2, library, true, followVar, errors);
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}
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}
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if (tok1->varId() != tok2->varId() || tok1->str() != tok2->str() || tok1->originalName() != tok2->originalName()) {
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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, macro, tok1->astOperand1(), tok2->astOperand2(), library, pure, followVar, errors) &&
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isSameExpression(cpp, macro, tok1->astOperand2(), tok2->astOperand1(), library, pure, followVar, errors);
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}
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return false;
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}
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if (macro && (tok1->isExpandedMacro() || tok2->isExpandedMacro() || tok1->isTemplateArg() || tok2->isTemplateArg()))
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return false;
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if (tok1->isComplex() != tok2->isComplex())
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return false;
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if (tok1->isLong() != tok2->isLong())
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return false;
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if (tok1->isUnsigned() != tok2->isUnsigned())
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return false;
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if (tok1->isSigned() != tok2->isSigned())
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return false;
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if (pure && tok1->isName() && tok1->next()->str() == "(" && tok1->str() != "sizeof") {
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if (!tok1->function()) {
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if (Token::simpleMatch(tok1->previous(), ".")) {
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const Token *lhs = tok1->previous();
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while (Token::Match(lhs, "(|.|["))
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lhs = lhs->astOperand1();
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const bool lhsIsConst = (lhs->variable() && lhs->variable()->isConst()) ||
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(lhs->valueType() && lhs->valueType()->constness > 0) ||
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(Token::Match(lhs, "%var% . %name% (") && library.isFunctionConst(lhs->tokAt(2)));
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if (!lhsIsConst)
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return false;
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} else {
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const Token * ftok = tok1;
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if (Token::simpleMatch(tok1->previous(), "::"))
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ftok = tok1->previous();
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if (!library.isFunctionConst(ftok) && !ftok->isAttributeConst() && !ftok->isAttributePure())
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return false;
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}
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} else {
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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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}
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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 (pure && 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) {
|
|
if (t1->str() != t2->str())
|
|
return false;
|
|
t1 = t1->next();
|
|
t2 = t2->next();
|
|
}
|
|
if (t1 != end1 || t2 != end2)
|
|
return false;
|
|
}
|
|
if (tok1->tokType() == Token::eIncDecOp || tok1->isAssignmentOp())
|
|
return false;
|
|
// bailout when we see ({..})
|
|
if (tok1->str() == "{")
|
|
return false;
|
|
// cast => assert that the casts are equal
|
|
if (tok1->str() == "(" && tok1->previous() &&
|
|
!tok1->previous()->isName() &&
|
|
!(tok1->previous()->str() == ">" && tok1->previous()->link())) {
|
|
const Token *t1 = tok1->next();
|
|
const Token *t2 = tok2->next();
|
|
while (t1 && t2 &&
|
|
t1->str() == t2->str() &&
|
|
t1->isLong() == t2->isLong() &&
|
|
t1->isUnsigned() == t2->isUnsigned() &&
|
|
t1->isSigned() == t2->isSigned() &&
|
|
(t1->isName() || t1->str() == "*")) {
|
|
t1 = t1->next();
|
|
t2 = t2->next();
|
|
}
|
|
if (!t1 || !t2 || t1->str() != ")" || t2->str() != ")")
|
|
return false;
|
|
}
|
|
bool noncommutativeEquals =
|
|
isSameExpression(cpp, macro, tok1->astOperand1(), tok2->astOperand1(), library, pure, followVar, errors);
|
|
noncommutativeEquals = noncommutativeEquals &&
|
|
isSameExpression(cpp, macro, tok1->astOperand2(), tok2->astOperand2(), library, pure, followVar, errors);
|
|
|
|
if (noncommutativeEquals)
|
|
return true;
|
|
|
|
// in c++, a+b might be different to b+a, depending on the type of a and b
|
|
if (cpp && tok1->str() == "+" && tok1->isBinaryOp()) {
|
|
const ValueType* vt1 = tok1->astOperand1()->valueType();
|
|
const ValueType* vt2 = tok1->astOperand2()->valueType();
|
|
if (!(vt1 && (vt1->type >= ValueType::VOID || vt1->pointer) && vt2 && (vt2->type >= ValueType::VOID || vt2->pointer)))
|
|
return false;
|
|
}
|
|
|
|
const bool commutative = tok1->isBinaryOp() && Token::Match(tok1, "%or%|%oror%|+|*|&|&&|^|==|!=");
|
|
bool commutativeEquals = commutative &&
|
|
isSameExpression(cpp, macro, tok1->astOperand2(), tok2->astOperand1(), library, pure, followVar, errors);
|
|
commutativeEquals = commutativeEquals &&
|
|
isSameExpression(cpp, macro, tok1->astOperand1(), tok2->astOperand2(), library, pure, followVar, errors);
|
|
|
|
|
|
return commutativeEquals;
|
|
}
|
|
|
|
bool isEqualKnownValue(const Token * const tok1, const Token * const tok2)
|
|
{
|
|
return tok1->hasKnownValue() && tok2->hasKnownValue() && tok1->values() == tok2->values();
|
|
}
|
|
|
|
bool isDifferentKnownValues(const Token * const tok1, const Token * const tok2)
|
|
{
|
|
return tok1->hasKnownValue() && tok2->hasKnownValue() && tok1->values() != tok2->values();
|
|
}
|
|
|
|
static bool isZeroBoundCond(const Token * const cond)
|
|
{
|
|
if (cond == nullptr)
|
|
return false;
|
|
// Assume unsigned
|
|
// TODO: Handle reverse conditions
|
|
const bool isZero = cond->astOperand2()->getValue(0);
|
|
if (cond->str() == "==" || cond->str() == ">=")
|
|
return isZero;
|
|
if (cond->str() == "<=")
|
|
return true;
|
|
if (cond->str() == "<")
|
|
return !isZero;
|
|
if (cond->str() == ">")
|
|
return false;
|
|
return false;
|
|
}
|
|
|
|
bool isOppositeCond(bool isNot, bool cpp, const Token * const cond1, const Token * const cond2, const Library& library, bool pure, bool followVar, ErrorPath* errors)
|
|
{
|
|
if (!cond1 || !cond2)
|
|
return false;
|
|
|
|
if (cond1->str() == "!") {
|
|
if (cond2->str() == "!=") {
|
|
if (cond2->astOperand1() && cond2->astOperand1()->str() == "0")
|
|
return isSameExpression(cpp, true, cond1->astOperand1(), cond2->astOperand2(), library, pure, followVar, errors);
|
|
if (cond2->astOperand2() && cond2->astOperand2()->str() == "0")
|
|
return isSameExpression(cpp, true, cond1->astOperand1(), cond2->astOperand1(), library, pure, followVar, errors);
|
|
}
|
|
return isSameExpression(cpp, true, cond1->astOperand1(), cond2, library, pure, followVar, errors);
|
|
}
|
|
|
|
if (cond2->str() == "!")
|
|
return isOppositeCond(isNot, cpp, cond2, cond1, library, pure, followVar, errors);
|
|
|
|
if (!isNot) {
|
|
if (cond1->str() == "==" && cond2->str() == "==") {
|
|
if (isSameExpression(cpp, true, cond1->astOperand1(), cond2->astOperand1(), library, pure, followVar, errors))
|
|
return isDifferentKnownValues(cond1->astOperand2(), cond2->astOperand2());
|
|
if (isSameExpression(cpp, true, cond1->astOperand2(), cond2->astOperand2(), library, pure, followVar, errors))
|
|
return isDifferentKnownValues(cond1->astOperand1(), cond2->astOperand1());
|
|
}
|
|
// TODO: Handle reverse conditions
|
|
if (Library::isContainerYield(cond1, Library::Container::EMPTY, "empty") &&
|
|
Library::isContainerYield(cond2->astOperand1(), Library::Container::SIZE, "size") &&
|
|
cond1->astOperand1()->astOperand1()->varId() == cond2->astOperand1()->astOperand1()->astOperand1()->varId()) {
|
|
return !isZeroBoundCond(cond2);
|
|
}
|
|
|
|
if (Library::isContainerYield(cond2, Library::Container::EMPTY, "empty") &&
|
|
Library::isContainerYield(cond1->astOperand1(), Library::Container::SIZE, "size") &&
|
|
cond2->astOperand1()->astOperand1()->varId() == cond1->astOperand1()->astOperand1()->astOperand1()->varId()) {
|
|
return !isZeroBoundCond(cond1);
|
|
}
|
|
}
|
|
|
|
|
|
if (!cond1->isComparisonOp() || !cond2->isComparisonOp())
|
|
return false;
|
|
|
|
const std::string &comp1 = cond1->str();
|
|
|
|
// condition found .. get comparator
|
|
std::string comp2;
|
|
if (isSameExpression(cpp, true, cond1->astOperand1(), cond2->astOperand1(), library, pure, followVar, errors) &&
|
|
isSameExpression(cpp, true, cond1->astOperand2(), cond2->astOperand2(), library, pure, followVar, errors)) {
|
|
comp2 = cond2->str();
|
|
} else if (isSameExpression(cpp, true, cond1->astOperand1(), cond2->astOperand2(), library, pure, followVar, errors) &&
|
|
isSameExpression(cpp, true, cond1->astOperand2(), cond2->astOperand1(), library, pure, followVar, errors)) {
|
|
comp2 = cond2->str();
|
|
if (comp2[0] == '>')
|
|
comp2[0] = '<';
|
|
else if (comp2[0] == '<')
|
|
comp2[0] = '>';
|
|
}
|
|
|
|
if (!isNot && comp2.empty()) {
|
|
const Token *expr1 = nullptr, *value1 = nullptr, *expr2 = nullptr, *value2 = nullptr;
|
|
std::string op1 = cond1->str(), op2 = cond2->str();
|
|
if (cond1->astOperand2()->hasKnownIntValue()) {
|
|
expr1 = cond1->astOperand1();
|
|
value1 = cond1->astOperand2();
|
|
} else if (cond1->astOperand1()->hasKnownIntValue()) {
|
|
expr1 = cond1->astOperand2();
|
|
value1 = cond1->astOperand1();
|
|
if (op1[0] == '>')
|
|
op1[0] = '<';
|
|
else if (op1[0] == '<')
|
|
op1[0] = '>';
|
|
}
|
|
if (cond2->astOperand2()->hasKnownIntValue()) {
|
|
expr2 = cond2->astOperand1();
|
|
value2 = cond2->astOperand2();
|
|
} else if (cond2->astOperand1()->hasKnownIntValue()) {
|
|
expr2 = cond2->astOperand2();
|
|
value2 = cond2->astOperand1();
|
|
if (op2[0] == '>')
|
|
op2[0] = '<';
|
|
else if (op2[0] == '<')
|
|
op2[0] = '>';
|
|
}
|
|
if (!expr1 || !value1 || !expr2 || !value2) {
|
|
return false;
|
|
}
|
|
if (!isSameExpression(cpp, true, expr1, expr2, library, pure, followVar, errors))
|
|
return false;
|
|
|
|
const ValueFlow::Value &rhsValue1 = value1->values().front();
|
|
const ValueFlow::Value &rhsValue2 = value2->values().front();
|
|
|
|
if (op1 == "<" || op1 == "<=")
|
|
return (op2 == "==" || op2 == ">" || op2 == ">=") && (rhsValue1.intvalue < rhsValue2.intvalue);
|
|
else if (op1 == ">=" || op1 == ">")
|
|
return (op2 == "==" || op2 == "<" || op2 == "<=") && (rhsValue1.intvalue > rhsValue2.intvalue);
|
|
|
|
return false;
|
|
}
|
|
|
|
// is condition opposite?
|
|
return ((comp1 == "==" && comp2 == "!=") ||
|
|
(comp1 == "!=" && comp2 == "==") ||
|
|
(comp1 == "<" && comp2 == ">=") ||
|
|
(comp1 == "<=" && comp2 == ">") ||
|
|
(comp1 == ">" && comp2 == "<=") ||
|
|
(comp1 == ">=" && comp2 == "<") ||
|
|
(!isNot && ((comp1 == "<" && comp2 == ">") ||
|
|
(comp1 == ">" && comp2 == "<") ||
|
|
(comp1 == "==" && (comp2 == "!=" || comp2 == ">" || comp2 == "<")) ||
|
|
((comp1 == "!=" || comp1 == ">" || comp1 == "<") && comp2 == "==")
|
|
)));
|
|
}
|
|
|
|
bool isOppositeExpression(bool cpp, const Token * const tok1, const Token * const tok2, const Library& library, bool pure, bool followVar, ErrorPath* errors)
|
|
{
|
|
if (!tok1 || !tok2)
|
|
return false;
|
|
if (isOppositeCond(true, cpp, tok1, tok2, library, pure, followVar, errors))
|
|
return true;
|
|
if (tok1->isUnaryOp("-"))
|
|
return isSameExpression(cpp, true, tok1->astOperand1(), tok2, library, pure, followVar, errors);
|
|
if (tok2->isUnaryOp("-"))
|
|
return isSameExpression(cpp, true, tok2->astOperand1(), tok1, library, pure, followVar, errors);
|
|
return false;
|
|
}
|
|
|
|
bool isConstExpression(const Token *tok, const Library& library, bool pure, bool cpp)
|
|
{
|
|
if (!tok)
|
|
return true;
|
|
if (tok->isName() && tok->next()->str() == "(") {
|
|
if (!tok->function() && !Token::Match(tok->previous(), ".|::") && !library.isFunctionConst(tok->str(), pure))
|
|
return false;
|
|
else if (tok->function() && !tok->function()->isConst())
|
|
return false;
|
|
}
|
|
if (tok->tokType() == Token::eIncDecOp)
|
|
return false;
|
|
if (tok->isAssignmentOp())
|
|
return false;
|
|
if (isLikelyStreamRead(cpp, tok))
|
|
return false;
|
|
// bailout when we see ({..})
|
|
if (tok->str() == "{")
|
|
return false;
|
|
return isConstExpression(tok->astOperand1(), library, pure, cpp) && isConstExpression(tok->astOperand2(), library, pure, cpp);
|
|
}
|
|
|
|
bool isWithoutSideEffects(bool cpp, const Token* tok)
|
|
{
|
|
if (!cpp)
|
|
return true;
|
|
|
|
while (tok && tok->astOperand2() && tok->astOperand2()->str() != "(")
|
|
tok = tok->astOperand2();
|
|
if (tok && tok->varId()) {
|
|
const Variable* var = tok->variable();
|
|
return var && (!var->isClass() || var->isPointer() || var->isStlType());
|
|
}
|
|
return true;
|
|
}
|
|
|
|
bool isUniqueExpression(const Token* tok)
|
|
{
|
|
if (!tok)
|
|
return true;
|
|
if (tok->function()) {
|
|
const Function * fun = tok->function();
|
|
const Scope * scope = fun->nestedIn;
|
|
if (!scope)
|
|
return true;
|
|
const std::string returnType = fun->retType ? fun->retType->name() : fun->retDef->stringifyList(fun->tokenDef);
|
|
for (const Function& f:scope->functionList) {
|
|
if (f.type != Function::eFunction)
|
|
continue;
|
|
|
|
const std::string freturnType = f.retType ? f.retType->name() : f.retDef->stringifyList(f.tokenDef);
|
|
if (f.argumentList.size() == fun->argumentList.size() &&
|
|
returnType == freturnType &&
|
|
f.name() != fun->name()) {
|
|
return false;
|
|
}
|
|
}
|
|
} else if (tok->variable()) {
|
|
const Variable * var = tok->variable();
|
|
const Scope * scope = var->scope();
|
|
if (!scope)
|
|
return true;
|
|
const Type * varType = var->type();
|
|
// Iterate over the variables in scope and the parameters of the function if possible
|
|
const Function * fun = scope->function;
|
|
const std::list<Variable>* setOfVars[] = {&scope->varlist, fun ? &fun->argumentList : nullptr};
|
|
|
|
for (const std::list<Variable>* vars:setOfVars) {
|
|
if (!vars)
|
|
continue;
|
|
bool other = std::any_of(vars->cbegin(), vars->cend(), [=](const Variable &v) {
|
|
if (varType)
|
|
return v.type() && v.type()->name() == varType->name() && v.name() != var->name();
|
|
return v.isFloatingType() == var->isFloatingType() &&
|
|
v.isEnumType() == var->isEnumType() &&
|
|
v.isClass() == var->isClass() &&
|
|
v.isArray() == var->isArray() &&
|
|
v.isPointer() == var->isPointer() &&
|
|
v.name() != var->name();
|
|
});
|
|
if (other)
|
|
return false;
|
|
}
|
|
} else if (!isUniqueExpression(tok->astOperand1())) {
|
|
return false;
|
|
}
|
|
|
|
return isUniqueExpression(tok->astOperand2());
|
|
}
|
|
|
|
bool isReturnScope(const Token * const endToken)
|
|
{
|
|
if (!endToken || endToken->str() != "}")
|
|
return false;
|
|
|
|
const Token *prev = endToken->previous();
|
|
while (prev && Token::simpleMatch(prev->previous(), "; ;"))
|
|
prev = prev->previous();
|
|
if (prev && Token::simpleMatch(prev->previous(), "} ;"))
|
|
prev = prev->previous();
|
|
|
|
if (Token::simpleMatch(prev, "}")) {
|
|
if (Token::simpleMatch(prev->link()->tokAt(-2), "} else {"))
|
|
return isReturnScope(prev) && isReturnScope(prev->link()->tokAt(-2));
|
|
if (Token::simpleMatch(prev->link()->previous(), ") {") &&
|
|
Token::simpleMatch(prev->link()->linkAt(-1)->previous(), "switch (") &&
|
|
!Token::findsimplematch(prev->link(), "break", prev)) {
|
|
return true;
|
|
}
|
|
if (Token::Match(prev->link()->astTop(), "return|throw"))
|
|
return true;
|
|
if (Token::Match(prev->link()->previous(), "[;{}] {"))
|
|
return isReturnScope(prev);
|
|
} else if (Token::simpleMatch(prev, ";")) {
|
|
// noreturn function
|
|
if (Token::simpleMatch(prev->previous(), ") ;") && Token::Match(prev->linkAt(-1)->tokAt(-2), "[;{}] %name% ("))
|
|
return true;
|
|
if (Token::simpleMatch(prev->previous(), ") ;") && prev->previous()->link() &&
|
|
Token::Match(prev->previous()->link()->astTop(), "return|throw"))
|
|
return true;
|
|
if (Token::Match(prev->previous()->astTop(), "return|throw"))
|
|
return true;
|
|
// return/goto statement
|
|
prev = prev->previous();
|
|
while (prev && !Token::Match(prev, ";|{|}|return|goto|throw|continue|break"))
|
|
prev = prev->previous();
|
|
return prev && prev->isName();
|
|
}
|
|
return false;
|
|
}
|
|
|
|
bool isVariableChangedByFunctionCall(const Token *tok, unsigned int varid, const Settings *settings, bool *inconclusive)
|
|
{
|
|
if (!tok)
|
|
return false;
|
|
if (tok->varId() == varid)
|
|
return isVariableChangedByFunctionCall(tok, settings, inconclusive);
|
|
return isVariableChangedByFunctionCall(tok->astOperand1(), varid, settings, inconclusive) ||
|
|
isVariableChangedByFunctionCall(tok->astOperand2(), varid, settings, inconclusive);
|
|
}
|
|
|
|
bool isVariableChangedByFunctionCall(const Token *tok, const Settings *settings, bool *inconclusive)
|
|
{
|
|
if (!tok)
|
|
return false;
|
|
|
|
const Token * const tok1 = tok;
|
|
|
|
// address of variable
|
|
const bool addressOf = tok->astParent() && tok->astParent()->isUnaryOp("&");
|
|
|
|
{
|
|
const Token *parent = tok->astParent();
|
|
if (parent && parent->isUnaryOp("&"))
|
|
parent = parent->astParent();
|
|
while (parent && parent->isCast())
|
|
parent = parent->astParent();
|
|
|
|
// passing variable to subfunction?
|
|
if (Token::Match(parent, "[(,]"))
|
|
;
|
|
else if (Token::simpleMatch(parent, ":")) {
|
|
while (Token::Match(parent, "[?:]"))
|
|
parent = parent->astParent();
|
|
while (Token::simpleMatch(parent, ","))
|
|
parent = parent->astParent();
|
|
if (!parent || parent->str() != "(")
|
|
return false;
|
|
} else
|
|
return false;
|
|
}
|
|
|
|
// goto start of function call and get argnr
|
|
unsigned int argnr = 0;
|
|
while (tok && !Token::Match(tok, "[;{}]")) {
|
|
if (tok->str() == ",")
|
|
++argnr;
|
|
else if (tok->str() == ")")
|
|
tok = tok->link();
|
|
else if (Token::Match(tok->previous(), "%name% ("))
|
|
break;
|
|
else if (Token::simpleMatch(tok->previous(), "> (") && tok->previous()->link())
|
|
break;
|
|
tok = tok->previous();
|
|
}
|
|
if (!tok || tok->str() != "(")
|
|
return false;
|
|
const bool possiblyPassedByReference = (tok->next() == tok1 || Token::Match(tok1->previous(), ", %name% [,)]"));
|
|
tok = tok->previous();
|
|
if (tok && tok->link() && tok->str() == ">")
|
|
tok = tok->link()->previous();
|
|
if (!Token::Match(tok, "%name% [(<]"))
|
|
return false; // not a function => variable not changed
|
|
|
|
// Constructor call
|
|
if (tok->variable() && tok->variable()->nameToken() == tok) {
|
|
// Find constructor..
|
|
const unsigned int argCount = numberOfArguments(tok);
|
|
const Scope *typeScope = tok->variable()->typeScope();
|
|
if (typeScope) {
|
|
for (const Function &function : typeScope->functionList) {
|
|
if (!function.isConstructor() || function.argCount() < argCount)
|
|
continue;
|
|
const Variable *arg = function.getArgumentVar(argnr);
|
|
if (arg && arg->isReference() && !arg->isConst())
|
|
return true;
|
|
}
|
|
return false;
|
|
}
|
|
if (inconclusive)
|
|
*inconclusive = true;
|
|
return false;
|
|
}
|
|
|
|
if (!tok->function()) {
|
|
// Check if direction (in, out, inout) is specified in the library configuration and use that
|
|
if (!addressOf && settings) {
|
|
const Library::ArgumentChecks::Direction argDirection = settings->library.getArgDirection(tok, 1 + argnr);
|
|
if (argDirection == Library::ArgumentChecks::Direction::DIR_IN)
|
|
return false;
|
|
else if (argDirection == Library::ArgumentChecks::Direction::DIR_OUT ||
|
|
argDirection == Library::ArgumentChecks::Direction::DIR_INOUT) {
|
|
// With out or inout the direction of the content is specified, not a pointer itself, so ignore pointers for now
|
|
const ValueType * const valueType = tok1->valueType();
|
|
if (valueType && !valueType->pointer) {
|
|
return true;
|
|
}
|
|
}
|
|
}
|
|
|
|
// if the library says 0 is invalid
|
|
// => it is assumed that parameter is an in parameter (TODO: this is a bad heuristic)
|
|
if (!addressOf && settings && settings->library.isnullargbad(tok, 1+argnr))
|
|
return false;
|
|
// possible pass-by-reference => inconclusive
|
|
if (possiblyPassedByReference) {
|
|
if (inconclusive != nullptr)
|
|
*inconclusive = true;
|
|
return false;
|
|
}
|
|
// Safe guess: Assume that parameter is changed by function call
|
|
return true;
|
|
}
|
|
|
|
const Variable *arg = tok->function()->getArgumentVar(argnr);
|
|
|
|
if (addressOf) {
|
|
if (!(arg && arg->isConst()))
|
|
return true;
|
|
// If const is applied to the pointer, then the value can still be modified
|
|
if (arg && Token::simpleMatch(arg->typeEndToken(), "* const"))
|
|
return true;
|
|
}
|
|
|
|
return arg && !arg->isConst() && arg->isReference();
|
|
}
|
|
|
|
bool isVariableChanged(const Token *start, const Token *end, const unsigned int varid, bool globalvar, const Settings *settings, bool cpp)
|
|
{
|
|
for (const Token *tok = start; tok != end; tok = tok->next()) {
|
|
if (tok->varId() != varid) {
|
|
if (globalvar && Token::Match(tok, "%name% ("))
|
|
// TODO: Is global variable really changed by function call?
|
|
return true;
|
|
continue;
|
|
}
|
|
|
|
const Token *tok2 = tok;
|
|
while (Token::simpleMatch(tok2->astParent(), "*"))
|
|
tok2 = tok2->astParent();
|
|
|
|
if (Token::Match(tok2->astParent(), "++|--"))
|
|
return true;
|
|
|
|
if (tok2->astParent() && tok2->astParent()->isAssignmentOp() && tok2 == tok2->astParent()->astOperand1())
|
|
return true;
|
|
|
|
if (isLikelyStreamRead(cpp, tok->previous()))
|
|
return true;
|
|
|
|
// Member function call
|
|
if (Token::Match(tok, "%name% . %name% (")) {
|
|
const Variable * var = tok->variable();
|
|
bool isConst = var && var->isConst();
|
|
if (!isConst && var) {
|
|
const ValueType * valueType = var->valueType();
|
|
isConst = (valueType && valueType->pointer == 1 && valueType->constness == 1);
|
|
}
|
|
|
|
const Token *ftok = tok->tokAt(2);
|
|
const Function * fun = ftok->function();
|
|
if (!isConst && (!fun || !fun->isConst()))
|
|
return true;
|
|
}
|
|
|
|
const Token *ftok = tok;
|
|
while (ftok && (!Token::Match(ftok, "[({[]") || ftok->isCast()))
|
|
ftok = ftok->astParent();
|
|
|
|
if (ftok && Token::Match(ftok->link(), ") !!{")) {
|
|
bool inconclusive = false;
|
|
bool isChanged = isVariableChangedByFunctionCall(tok, settings, &inconclusive);
|
|
isChanged |= inconclusive;
|
|
if (isChanged)
|
|
return true;
|
|
}
|
|
|
|
const Token *parent = tok->astParent();
|
|
while (Token::Match(parent, ".|::"))
|
|
parent = parent->astParent();
|
|
if (parent && parent->tokType() == Token::eIncDecOp)
|
|
return true;
|
|
}
|
|
return false;
|
|
}
|
|
|
|
bool isVariableChanged(const Variable * var, const Settings *settings, bool cpp)
|
|
{
|
|
if (!var)
|
|
return false;
|
|
if (!var->scope())
|
|
return false;
|
|
const Token * start = var->declEndToken();
|
|
if (!start)
|
|
return false;
|
|
if (Token::Match(start, "; %varid% =", var->declarationId()))
|
|
start = start->tokAt(2);
|
|
return isVariableChanged(start->next(), var->scope()->bodyEnd, var->declarationId(), var->isGlobal(), settings, cpp);
|
|
}
|
|
|
|
int numberOfArguments(const Token *start)
|
|
{
|
|
int arguments=0;
|
|
const Token* const openBracket = start->next();
|
|
if (openBracket && openBracket->str()=="(" && openBracket->next() && openBracket->next()->str()!=")") {
|
|
const Token* argument=openBracket->next();
|
|
while (argument) {
|
|
++arguments;
|
|
argument = argument->nextArgument();
|
|
}
|
|
}
|
|
return arguments;
|
|
}
|
|
|
|
static void getArgumentsRecursive(const Token *tok, std::vector<const Token *> *arguments, unsigned int depth)
|
|
{
|
|
++depth;
|
|
if (!tok || depth >= 100)
|
|
return;
|
|
if (tok->str() == ",") {
|
|
getArgumentsRecursive(tok->astOperand1(), arguments, depth);
|
|
getArgumentsRecursive(tok->astOperand2(), arguments, depth);
|
|
} else {
|
|
arguments->push_back(tok);
|
|
}
|
|
}
|
|
|
|
std::vector<const Token *> getArguments(const Token *ftok)
|
|
{
|
|
std::vector<const Token *> arguments;
|
|
const Token *tok = ftok->next();
|
|
if (!Token::Match(tok, "(|{"))
|
|
tok = ftok;
|
|
const Token *startTok = tok->astOperand2();
|
|
if (!startTok && Token::simpleMatch(tok->astOperand1(), ","))
|
|
startTok = tok->astOperand1();
|
|
getArgumentsRecursive(startTok, &arguments, 0);
|
|
return arguments;
|
|
}
|
|
|
|
const Token *findLambdaStartToken(const Token *last)
|
|
{
|
|
if (!last || last->str() != "}")
|
|
return nullptr;
|
|
const Token* tok = last->link();
|
|
if (Token::simpleMatch(tok->astParent(), "("))
|
|
tok = tok->astParent();
|
|
if (Token::simpleMatch(tok->astParent(), "["))
|
|
return tok->astParent();
|
|
return nullptr;
|
|
}
|
|
|
|
const Token *findLambdaEndToken(const Token *first)
|
|
{
|
|
if (!first || first->str() != "[")
|
|
return nullptr;
|
|
if (!Token::Match(first->link(), "] (|{"))
|
|
return nullptr;
|
|
if (first->astOperand1() != first->link()->next())
|
|
return nullptr;
|
|
const Token * tok = first;
|
|
|
|
if (tok->astOperand1() && tok->astOperand1()->str() == "(")
|
|
tok = tok->astOperand1();
|
|
if (tok->astOperand1() && tok->astOperand1()->str() == "{")
|
|
return tok->astOperand1()->link();
|
|
return nullptr;
|
|
}
|
|
|
|
bool isLikelyStreamRead(bool cpp, const Token *op)
|
|
{
|
|
if (!cpp)
|
|
return false;
|
|
|
|
if (!Token::Match(op, "&|>>") || !op->isBinaryOp())
|
|
return false;
|
|
|
|
if (!Token::Match(op->astOperand2(), "%name%|.|*|[") && op->str() != op->astOperand2()->str())
|
|
return false;
|
|
|
|
const Token *parent = op;
|
|
while (parent->astParent() && parent->astParent()->str() == op->str())
|
|
parent = parent->astParent();
|
|
if (parent->astParent() && !Token::Match(parent->astParent(), "%oror%|&&|(|,|!"))
|
|
return false;
|
|
if (op->str() == "&" && parent->astParent())
|
|
return false;
|
|
if (!parent->astOperand1() || !parent->astOperand2())
|
|
return false;
|
|
return (!parent->astOperand1()->valueType() || !parent->astOperand1()->valueType()->isIntegral());
|
|
}
|
|
|
|
bool isCPPCast(const Token* tok)
|
|
{
|
|
return tok && Token::simpleMatch(tok->previous(), "> (") && tok->astOperand2() && tok->astOperand1() && tok->astOperand1()->str().find("_cast") != std::string::npos;
|
|
}
|
|
|
|
bool isConstVarExpression(const Token *tok)
|
|
{
|
|
if (!tok)
|
|
return false;
|
|
if (Token::simpleMatch(tok->previous(), "sizeof ("))
|
|
return true;
|
|
if (Token::Match(tok->previous(), "%name% (")) {
|
|
std::vector<const Token *> args = getArguments(tok);
|
|
return std::all_of(args.begin(), args.end(), &isConstVarExpression);
|
|
}
|
|
if (isCPPCast(tok)) {
|
|
return isConstVarExpression(tok->astOperand2());
|
|
}
|
|
if (Token::Match(tok, "( %type%"))
|
|
return isConstVarExpression(tok->astOperand1());
|
|
if (Token::Match(tok, "%cop%|[|.")) {
|
|
if (tok->astOperand1() && !isConstVarExpression(tok->astOperand1()))
|
|
return false;
|
|
if (tok->astOperand2() && !isConstVarExpression(tok->astOperand2()))
|
|
return false;
|
|
return true;
|
|
}
|
|
if (Token::Match(tok, "%bool%|%num%|%str%|%char%|nullptr|NULL"))
|
|
return true;
|
|
if (tok->isEnumerator())
|
|
return true;
|
|
if (tok->variable())
|
|
return tok->variable()->isConst();
|
|
return false;
|
|
}
|
|
|
|
static bool nonLocal(const Variable* var, bool deref)
|
|
{
|
|
return !var || (!var->isLocal() && !var->isArgument()) || (deref && var->isArgument() && var->isPointer()) || var->isStatic() || var->isReference() || var->isExtern();
|
|
}
|
|
|
|
static bool hasFunctionCall(const Token *tok)
|
|
{
|
|
if (!tok)
|
|
return false;
|
|
if (Token::Match(tok, "%name% ("))
|
|
// todo, const/pure function?
|
|
return true;
|
|
return hasFunctionCall(tok->astOperand1()) || hasFunctionCall(tok->astOperand2());
|
|
}
|
|
|
|
struct FwdAnalysis::Result FwdAnalysis::checkRecursive(const Token *expr, const Token *startToken, const Token *endToken, const std::set<unsigned int> &exprVarIds, bool local)
|
|
{
|
|
// Parse the given tokens
|
|
for (const Token *tok = startToken; tok != endToken; tok = tok->next()) {
|
|
if (Token::simpleMatch(tok, "try {")) {
|
|
// TODO: handle try
|
|
return Result(Result::Type::BAILOUT);
|
|
}
|
|
|
|
if (Token::simpleMatch(tok, "break ;")) {
|
|
return Result(Result::Type::BREAK, tok);
|
|
}
|
|
|
|
if (Token::simpleMatch(tok, "goto"))
|
|
return Result(Result::Type::BAILOUT);
|
|
|
|
if (tok->str() == "continue")
|
|
// TODO
|
|
return Result(Result::Type::BAILOUT);
|
|
|
|
if (const Token *lambdaEndToken = findLambdaEndToken(tok)) {
|
|
tok = lambdaEndToken;
|
|
const Result lambdaResult = checkRecursive(expr, lambdaEndToken->link()->next(), lambdaEndToken, exprVarIds, local);
|
|
if (lambdaResult.type == Result::Type::READ || lambdaResult.type == Result::Type::BAILOUT)
|
|
return lambdaResult;
|
|
}
|
|
|
|
if (Token::Match(tok, "return|throw")) {
|
|
// TODO: Handle these better
|
|
// Is expr variable used in expression?
|
|
const Token *end = tok->findExpressionStartEndTokens().second->next();
|
|
for (const Token *tok2 = tok; tok2 != end; tok2 = tok2->next()) {
|
|
if (!local && Token::Match(tok2, "%name% ("))
|
|
return Result(Result::Type::READ);
|
|
if (tok2->varId() && exprVarIds.find(tok2->varId()) != exprVarIds.end())
|
|
return Result(Result::Type::READ);
|
|
}
|
|
|
|
if (!local && mWhat == What::Reassign)
|
|
return Result(Result::Type::BAILOUT);
|
|
|
|
return Result(Result::Type::RETURN);
|
|
}
|
|
|
|
if (tok->str() == "}") {
|
|
// Known value => possible value
|
|
if (tok->scope() == expr->scope())
|
|
mValueFlowKnown = false;
|
|
|
|
Scope::ScopeType scopeType = tok->scope()->type;
|
|
if (scopeType == Scope::eWhile || scopeType == Scope::eFor || scopeType == Scope::eDo) {
|
|
// check condition
|
|
const Token *conditionStart = nullptr;
|
|
const Token *conditionEnd = nullptr;
|
|
if (Token::simpleMatch(tok->link()->previous(), ") {")) {
|
|
conditionEnd = tok->link()->previous();
|
|
conditionStart = conditionEnd->link();
|
|
} else if (Token::simpleMatch(tok->link()->previous(), "do {") && Token::simpleMatch(tok, "} while (")) {
|
|
conditionStart = tok->tokAt(2);
|
|
conditionEnd = conditionStart->link();
|
|
}
|
|
if (conditionStart && conditionEnd) {
|
|
bool used = false;
|
|
for (const Token *condTok = conditionStart; condTok != conditionEnd; condTok = condTok->next()) {
|
|
if (exprVarIds.find(condTok->varId()) != exprVarIds.end())
|
|
used = true;
|
|
}
|
|
if (used)
|
|
return Result(Result::Type::BAILOUT);
|
|
}
|
|
|
|
// check loop body again..
|
|
const struct FwdAnalysis::Result &result = checkRecursive(expr, tok->link(), tok, exprVarIds, local);
|
|
if (result.type == Result::Type::BAILOUT || result.type == Result::Type::READ)
|
|
return result;
|
|
}
|
|
}
|
|
|
|
if (Token::simpleMatch(tok, "else {"))
|
|
tok = tok->linkAt(1);
|
|
|
|
if (Token::simpleMatch(tok, "asm ("))
|
|
return Result(Result::Type::BAILOUT);
|
|
|
|
if (mWhat == What::ValueFlow && Token::Match(tok, "while|for (")) {
|
|
// TODO: only bailout if expr is reassigned in loop
|
|
return Result(Result::Type::BAILOUT);
|
|
}
|
|
|
|
if (!local && Token::Match(tok, "%name% (") && !Token::simpleMatch(tok->linkAt(1), ") {")) {
|
|
// TODO: this is a quick bailout
|
|
return Result(Result::Type::BAILOUT);
|
|
}
|
|
|
|
if (expr->isName() && Token::Match(tok, "%name% (") && tok->str().find("<") != std::string::npos && tok->str().find(expr->str()) != std::string::npos)
|
|
return Result(Result::Type::BAILOUT);
|
|
|
|
|
|
if (exprVarIds.find(tok->varId()) != exprVarIds.end()) {
|
|
const Token *parent = tok;
|
|
bool other = false;
|
|
bool same = tok->astParent() && isSameExpression(mCpp, false, expr, tok, mLibrary, false, false, nullptr);
|
|
while (!same && Token::Match(parent->astParent(), "*|.|::|[")) {
|
|
parent = parent->astParent();
|
|
if (parent && isSameExpression(mCpp, false, expr, parent, mLibrary, false, false, nullptr)) {
|
|
same = true;
|
|
if (mWhat == What::ValueFlow) {
|
|
KnownAndToken v;
|
|
v.known = mValueFlowKnown;
|
|
v.token = parent;
|
|
mValueFlow.push_back(v);
|
|
}
|
|
}
|
|
if (Token::Match(parent, ". %var%") && parent->next()->varId() && exprVarIds.find(parent->next()->varId()) == exprVarIds.end()) {
|
|
other = true;
|
|
break;
|
|
}
|
|
}
|
|
if (mWhat != What::ValueFlow && same && Token::simpleMatch(parent->astParent(), "[") && parent == parent->astParent()->astOperand2()) {
|
|
return Result(Result::Type::READ);
|
|
}
|
|
if (other)
|
|
continue;
|
|
if (Token::simpleMatch(parent->astParent(), "=") && parent == parent->astParent()->astOperand1()) {
|
|
if (!local && hasFunctionCall(parent->astParent()->astOperand2())) {
|
|
// TODO: this is a quick bailout
|
|
return Result(Result::Type::BAILOUT);
|
|
}
|
|
if (hasOperand(parent->astParent()->astOperand2(), expr)) {
|
|
if (mWhat == What::Reassign)
|
|
return Result(Result::Type::READ);
|
|
continue;
|
|
}
|
|
const bool reassign = isSameExpression(mCpp, false, expr, parent, mLibrary, false, false, nullptr);
|
|
if (reassign)
|
|
return Result(Result::Type::WRITE, parent->astParent());
|
|
return Result(Result::Type::READ);
|
|
} else if (Token::Match(parent->astParent(), "%assign%") && !parent->astParent()->astParent() && parent == parent->astParent()->astOperand1()) {
|
|
continue;
|
|
} else {
|
|
// TODO: this is a quick bailout
|
|
return Result(Result::Type::BAILOUT, parent->astParent());
|
|
}
|
|
}
|
|
|
|
if (Token::simpleMatch(tok, ") {")) {
|
|
if (Token::simpleMatch(tok->link()->previous(), "switch ("))
|
|
// TODO: parse switch
|
|
return Result(Result::Type::BAILOUT);
|
|
const Result &result1 = checkRecursive(expr, tok->tokAt(2), tok->linkAt(1), exprVarIds, local);
|
|
if (result1.type == Result::Type::READ || result1.type == Result::Type::BAILOUT)
|
|
return result1;
|
|
if (mWhat == What::ValueFlow && result1.type == Result::Type::WRITE)
|
|
mValueFlowKnown = false;
|
|
if (Token::simpleMatch(tok->linkAt(1), "} else {")) {
|
|
const Token *elseStart = tok->linkAt(1)->tokAt(2);
|
|
const Result &result2 = checkRecursive(expr, elseStart, elseStart->link(), exprVarIds, local);
|
|
if (mWhat == What::ValueFlow && result2.type == Result::Type::WRITE)
|
|
mValueFlowKnown = false;
|
|
if (result2.type == Result::Type::READ || result2.type == Result::Type::BAILOUT)
|
|
return result2;
|
|
if (result1.type == Result::Type::WRITE && result2.type == Result::Type::WRITE)
|
|
return result1;
|
|
tok = elseStart->link();
|
|
} else {
|
|
tok = tok->linkAt(1);
|
|
}
|
|
}
|
|
}
|
|
|
|
return Result(Result::Type::NONE);
|
|
}
|
|
|
|
bool FwdAnalysis::isGlobalData(const Token *expr) const
|
|
{
|
|
bool globalData = false;
|
|
visitAstNodes(expr,
|
|
[&](const Token *tok) {
|
|
if (tok->varId() && !tok->variable()) {
|
|
// Bailout, this is probably global
|
|
globalData = true;
|
|
return ChildrenToVisit::none;
|
|
}
|
|
if (tok->originalName() == "->") {
|
|
// TODO check if pointer points at local data
|
|
globalData = true;
|
|
return ChildrenToVisit::none;
|
|
} else if (Token::Match(tok, "[*[]") && tok->astOperand1() && tok->astOperand1()->variable()) {
|
|
// TODO check if pointer points at local data
|
|
const Variable *lhsvar = tok->astOperand1()->variable();
|
|
const ValueType *lhstype = tok->astOperand1()->valueType();
|
|
if (lhsvar->isPointer()) {
|
|
globalData = true;
|
|
return ChildrenToVisit::none;
|
|
} else if (lhsvar->isArgument() && lhsvar->isArray()) {
|
|
globalData = true;
|
|
return ChildrenToVisit::none;
|
|
} else if (lhsvar->isArgument() && (!lhstype || (lhstype->type <= ValueType::Type::VOID && !lhstype->container))) {
|
|
globalData = true;
|
|
return ChildrenToVisit::none;
|
|
}
|
|
}
|
|
if (tok->varId() == 0 && tok->isName() && tok->previous()->str() != ".") {
|
|
globalData = true;
|
|
return ChildrenToVisit::none;
|
|
}
|
|
if (tok->variable()) {
|
|
// TODO : Check references
|
|
if (tok->variable()->isReference() && tok != tok->variable()->nameToken()) {
|
|
globalData = true;
|
|
return ChildrenToVisit::none;
|
|
}
|
|
if (tok->variable()->isExtern()) {
|
|
globalData = true;
|
|
return ChildrenToVisit::none;
|
|
}
|
|
if (tok->previous()->str() != "." && !tok->variable()->isLocal() && !tok->variable()->isArgument()) {
|
|
globalData = true;
|
|
return ChildrenToVisit::none;
|
|
}
|
|
if (tok->variable()->isArgument() && tok->variable()->isPointer() && tok != expr) {
|
|
globalData = true;
|
|
return ChildrenToVisit::none;
|
|
}
|
|
if (tok->variable()->isPointerArray()) {
|
|
globalData = true;
|
|
return ChildrenToVisit::none;
|
|
}
|
|
}
|
|
// Unknown argument type => it might be some reference type..
|
|
if (mCpp && tok->str() == "." && tok->astOperand1() && tok->astOperand1()->variable() && !tok->astOperand1()->valueType()) {
|
|
globalData = true;
|
|
return ChildrenToVisit::none;
|
|
}
|
|
if (Token::Match(tok, ".|["))
|
|
return ChildrenToVisit::op1;
|
|
return ChildrenToVisit::op1_and_op2;
|
|
});
|
|
return globalData;
|
|
}
|
|
|
|
FwdAnalysis::Result FwdAnalysis::check(const Token *expr, const Token *startToken, const Token *endToken)
|
|
{
|
|
// all variable ids in expr.
|
|
std::set<unsigned int> exprVarIds;
|
|
bool local = true;
|
|
bool unknownVarId = false;
|
|
visitAstNodes(expr,
|
|
[&](const Token *tok) {
|
|
if (tok->varId() == 0 && tok->isName() && tok->previous()->str() != ".") {
|
|
// unknown variable
|
|
unknownVarId = true;
|
|
return ChildrenToVisit::none;
|
|
}
|
|
if (tok->varId() > 0) {
|
|
exprVarIds.insert(tok->varId());
|
|
if (!Token::simpleMatch(tok->previous(), ".")) {
|
|
const Variable *var = tok->variable();
|
|
if (var && var->isReference() && var->isLocal() && Token::Match(var->nameToken(), "%var% [=(]") && !isGlobalData(var->nameToken()->next()->astOperand2()))
|
|
return ChildrenToVisit::none;
|
|
const bool deref = tok->astParent() && (tok->astParent()->isUnaryOp("*") || (tok->astParent()->str() == "[" && tok == tok->astParent()->astOperand1()));
|
|
local &= !nonLocal(tok->variable(), deref);
|
|
}
|
|
}
|
|
return ChildrenToVisit::op1_and_op2;
|
|
});
|
|
|
|
if (unknownVarId)
|
|
return Result(FwdAnalysis::Result::Type::BAILOUT);
|
|
|
|
if (mWhat == What::Reassign && isGlobalData(expr))
|
|
local = false;
|
|
|
|
// In unused values checking we do not want to check assignments to
|
|
// global data.
|
|
if (mWhat == What::UnusedValue && isGlobalData(expr))
|
|
return Result(FwdAnalysis::Result::Type::BAILOUT);
|
|
|
|
Result result = checkRecursive(expr, startToken, endToken, exprVarIds, local);
|
|
|
|
// Break => continue checking in outer scope
|
|
while (result.type == FwdAnalysis::Result::Type::BREAK) {
|
|
const Scope *s = result.token->scope();
|
|
while (s->type == Scope::eIf)
|
|
s = s->nestedIn;
|
|
if (s->type != Scope::eSwitch && s->type != Scope::eWhile && s->type != Scope::eFor)
|
|
break;
|
|
result = checkRecursive(expr, s->bodyEnd->next(), endToken, exprVarIds, local);
|
|
}
|
|
|
|
return result;
|
|
}
|
|
|
|
bool FwdAnalysis::hasOperand(const Token *tok, const Token *lhs) const
|
|
{
|
|
if (!tok)
|
|
return false;
|
|
if (isSameExpression(mCpp, false, tok, lhs, mLibrary, false, false, nullptr))
|
|
return true;
|
|
return hasOperand(tok->astOperand1(), lhs) || hasOperand(tok->astOperand2(), lhs);
|
|
}
|
|
|
|
const Token *FwdAnalysis::reassign(const Token *expr, const Token *startToken, const Token *endToken)
|
|
{
|
|
mWhat = What::Reassign;
|
|
Result result = check(expr, startToken, endToken);
|
|
return result.type == FwdAnalysis::Result::Type::WRITE ? result.token : nullptr;
|
|
}
|
|
|
|
bool FwdAnalysis::unusedValue(const Token *expr, const Token *startToken, const Token *endToken)
|
|
{
|
|
if (isEscapedAlias(expr))
|
|
return false;
|
|
mWhat = What::UnusedValue;
|
|
Result result = check(expr, startToken, endToken);
|
|
return (result.type == FwdAnalysis::Result::Type::NONE || result.type == FwdAnalysis::Result::Type::RETURN) && !possiblyAliased(expr, startToken);
|
|
}
|
|
|
|
std::vector<FwdAnalysis::KnownAndToken> FwdAnalysis::valueFlow(const Token *expr, const Token *startToken, const Token *endToken)
|
|
{
|
|
mWhat = What::ValueFlow;
|
|
mValueFlowKnown = true;
|
|
check(expr, startToken, endToken);
|
|
return mValueFlow;
|
|
}
|
|
|
|
bool FwdAnalysis::possiblyAliased(const Token *expr, const Token *startToken) const
|
|
{
|
|
if (expr->isUnaryOp("*"))
|
|
return true;
|
|
|
|
const bool macro = false;
|
|
const bool pure = false;
|
|
const bool followVar = false;
|
|
for (const Token *tok = startToken; tok; tok = tok->previous()) {
|
|
if (tok->str() == "{" && tok->scope()->type == Scope::eFunction)
|
|
break;
|
|
|
|
if (Token::Match(tok, "%name% (") && !Token::Match(tok, "if|while|for")) {
|
|
// Is argument passed by reference?
|
|
const std::vector<const Token*> args = getArguments(tok);
|
|
for (unsigned int argnr = 0; argnr < args.size(); ++argnr) {
|
|
if (!Token::Match(args[argnr], "%name%|.|::"))
|
|
continue;
|
|
if (tok->function() && tok->function()->getArgumentVar(argnr) && !tok->function()->getArgumentVar(argnr)->isReference() && !tok->function()->isConst())
|
|
continue;
|
|
for (const Token *subexpr = expr; subexpr; subexpr = subexpr->astOperand1()) {
|
|
if (isSameExpression(mCpp, macro, subexpr, args[argnr], mLibrary, pure, followVar))
|
|
return true;
|
|
}
|
|
}
|
|
continue;
|
|
}
|
|
|
|
const Token *addrOf = nullptr;
|
|
if (Token::Match(tok, "& %name% ="))
|
|
addrOf = tok->tokAt(2)->astOperand2();
|
|
else if (tok->isUnaryOp("&"))
|
|
addrOf = tok->astOperand1();
|
|
else if (Token::simpleMatch(tok, "std :: ref ("))
|
|
addrOf = tok->tokAt(3)->astOperand2();
|
|
else
|
|
continue;
|
|
|
|
for (const Token *subexpr = expr; subexpr; subexpr = subexpr->astOperand1()) {
|
|
if (isSameExpression(mCpp, macro, subexpr, addrOf, mLibrary, pure, followVar))
|
|
return true;
|
|
}
|
|
}
|
|
return false;
|
|
}
|
|
|
|
bool FwdAnalysis::isEscapedAlias(const Token* expr)
|
|
{
|
|
for (const Token *subexpr = expr; subexpr; subexpr = subexpr->astOperand1()) {
|
|
for (const ValueFlow::Value &val : subexpr->values()) {
|
|
if (!val.isLocalLifetimeValue())
|
|
continue;
|
|
const Variable* var = val.tokvalue->variable();
|
|
if (!var)
|
|
continue;
|
|
if (!var->isLocal())
|
|
return true;
|
|
if (var->isArgument())
|
|
return true;
|
|
|
|
}
|
|
}
|
|
return false;
|
|
}
|
|
|
|
bool FwdAnalysis::isNullOperand(const Token *expr)
|
|
{
|
|
if (!expr)
|
|
return false;
|
|
if (Token::Match(expr, "( %name% %name%| * )") && Token::Match(expr->astOperand1(), "0|NULL|nullptr"))
|
|
return true;
|
|
return Token::Match(expr, "NULL|nullptr");
|
|
}
|