2134 lines
89 KiB
C++
2134 lines
89 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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#include "valueflow.h"
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#include "errorlogger.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 "tokenlist.h"
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#include <stack>
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static void execute(const Token *expr,
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std::map<unsigned int, MathLib::bigint> * const programMemory,
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MathLib::bigint *result,
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bool *error);
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static void bailout(TokenList *tokenlist, ErrorLogger *errorLogger, const Token *tok, const std::string &what)
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{
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std::list<ErrorLogger::ErrorMessage::FileLocation> callstack;
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callstack.push_back(ErrorLogger::ErrorMessage::FileLocation(tok,tokenlist));
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ErrorLogger::ErrorMessage errmsg(callstack, Severity::debug, "ValueFlow bailout: " + what, "valueFlowBailout", false);
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errorLogger->reportErr(errmsg);
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}
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static bool bailoutFunctionPar(const Token *tok, const ValueFlow::Value &value, const Settings *settings, bool *inconclusive)
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{
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if (!tok)
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return false;
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// address of variable
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const bool addressOf = tok && Token::simpleMatch(tok->previous(), "&");
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// passing variable to subfunction?
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if (Token::Match(tok->tokAt(-2), ") & %name% [,)]") && Token::Match(tok->linkAt(-2)->previous(), "[,(] ("))
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;
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else if (Token::Match(tok->tokAt(addressOf?-2:-1), "[(,] &| %name% [,)]"))
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;
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else
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return false;
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// reinterpret_cast etc..
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if (Token::Match(tok->tokAt(-3), "> ( & %name% ) [,)]") &&
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tok->linkAt(-3) &&
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Token::Match(tok->linkAt(-3)->tokAt(-2), "[,(] %type% <"))
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tok = tok->linkAt(-3);
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// goto start of function call and get argnr
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unsigned int argnr = 0;
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while (tok && tok->str() != "(") {
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if (tok->str() == ",")
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++argnr;
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else if (tok->str() == ")")
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tok = tok->link();
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tok = tok->previous();
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}
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tok = tok ? tok->previous() : nullptr;
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if (!Token::Match(tok,"%name% ("))
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return false; // not a function => do not bailout
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if (!tok->function()) {
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// if value is 0 and the library says 0 is invalid => do not bailout
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if (value.intvalue==0 && settings->library.isnullargbad(tok, 1+argnr))
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return false;
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// addressOf => inconclusive
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if (!addressOf) {
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*inconclusive = true;
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return false;
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}
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return true;
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}
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const Variable *arg = tok->function()->getArgumentVar(argnr);
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if (addressOf && !(arg && arg->isConst()))
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return true;
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return arg && !arg->isConst() && arg->isReference();
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}
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/**
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* Is condition always false when variable has given value?
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* \param condition top ast token in condition
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* \param programMemory program memory
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*/
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static bool conditionIsFalse(const Token *condition, const std::map<unsigned int, MathLib::bigint> &programMemory)
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{
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if (!condition)
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return false;
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if (condition->str() == "&&") {
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const bool result1 = conditionIsFalse(condition->astOperand1(), programMemory);
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const bool result2 = result1 ? true : conditionIsFalse(condition->astOperand2(), programMemory);
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return result2;
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}
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std::map<unsigned int, MathLib::bigint> progmem(programMemory);
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MathLib::bigint result = 0;
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bool error = false;
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execute(condition, &progmem, &result, &error);
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return !error && result == 0;
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}
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/**
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* Is condition always true when variable has given value?
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* \param condition top ast token in condition
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* \param programMemory program memory
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*/
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static bool conditionIsTrue(const Token *condition, const std::map<unsigned int, MathLib::bigint> &programMemory)
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{
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if (!condition)
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return false;
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if (condition->str() == "||") {
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const bool result1 = conditionIsTrue(condition->astOperand1(), programMemory);
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const bool result2 = result1 ? true : conditionIsTrue(condition->astOperand2(), programMemory);
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return result2;
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}
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std::map<unsigned int, MathLib::bigint> progmem(programMemory);
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bool error = false;
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MathLib::bigint result = 0;
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execute(condition, &progmem, &result, &error);
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return !error && result == 1;
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}
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/**
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* Get program memory by looking backwards from given token.
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*/
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static std::map<unsigned int, MathLib::bigint> getProgramMemory(const Token *tok, unsigned int varid, const ValueFlow::Value &value)
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{
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std::map<unsigned int, MathLib::bigint> programMemory;
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programMemory[varid] = value.intvalue;
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if (value.varId)
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programMemory[value.varId] = value.varvalue;
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const std::map<unsigned int, MathLib::bigint> programMemory1(programMemory);
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int indentlevel = 0;
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for (const Token *tok2 = tok; tok2; tok2 = tok2->previous()) {
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if (Token::Match(tok2, "[;{}] %varid% = %var% ;", varid)) {
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const Token *vartok = tok2->tokAt(3);
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programMemory[vartok->varId()] = value.intvalue;
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}
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if (Token::Match(tok2, "[;{}] %var% =")) {
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const Token *vartok = tok2->next();
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if (programMemory.find(vartok->varId()) == programMemory.end()) {
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MathLib::bigint result = 0;
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bool error = false;
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execute(tok2->tokAt(2)->astOperand2(), &programMemory, &result, &error);
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if (!error)
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programMemory[vartok->varId()] = result;
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}
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}
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if (tok2->str() == "{") {
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if (indentlevel <= 0)
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break;
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--indentlevel;
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}
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if (tok2->str() == "}") {
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const Token *cond = tok2->link();
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cond = Token::simpleMatch(cond->previous(), ") {") ? cond->linkAt(-1) : nullptr;
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if (cond && conditionIsFalse(cond->astOperand2(), programMemory1))
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tok2 = cond->previous();
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else if (cond && conditionIsTrue(cond->astOperand2(), programMemory1)) {
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++indentlevel;
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continue;
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} else
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break;
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}
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}
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return programMemory;
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}
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/**
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* Should value be skipped because it's hidden inside && || or ?: expression.
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* Example: ((x!=NULL) && (*x == 123))
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* If 'valuetok' points at the x in '(*x == 123)'. Then the '&&' will be returned.
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* @param valuetok original variable token
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* @return NULL=>don't skip, non-NULL=>The operator token that cause the skip. For instance the '&&'.
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* */
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static const Token * skipValueInConditionalExpression(const Token * const valuetok)
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{
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// Walk up the ast
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const Token *prev = valuetok;
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for (const Token *tok = valuetok->astParent(); tok; tok = tok->astParent()) {
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const bool prevIsLhs = (prev == tok->astOperand1());
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prev = tok;
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if (prevIsLhs || !Token::Match(tok, "%oror%|&&|?|:"))
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continue;
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// Is variable protected in LHS..
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std::stack<const Token *> tokens;
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tokens.push(tok->astOperand1());
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while (!tokens.empty()) {
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const Token * const tok2 = tokens.top();
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tokens.pop();
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if (!tok2)
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continue;
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if (tok2 != valuetok && tok2->str() == valuetok->str())
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return tok;
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tokens.push(tok2->astOperand2());
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tokens.push(tok2->astOperand1());
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}
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}
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return nullptr;
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}
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static bool bailoutSelfAssignment(const Token * const tok)
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{
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const Token *parent = tok;
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while (parent) {
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const Token *op = parent;
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parent = parent->astParent();
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// Assignment where lhs variable exists in rhs => return true
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if (parent != nullptr &&
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parent->astOperand2() == op &&
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parent->astOperand1() != nullptr &&
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parent->str() == "=") {
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for (const Token *lhs = parent->astOperand1(); lhs; lhs = lhs->astOperand1()) {
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if (lhs->varId() == tok->varId())
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return true;
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if (lhs->astOperand2() && lhs->astOperand2()->varId() == tok->varId())
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return true;
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}
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}
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}
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return false;
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}
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static bool isReturn(const Token *tok)
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{
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if (!tok)
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return false;
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const Token *prev = tok->previous();
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if (prev && Token::simpleMatch(prev->previous(), "} ;"))
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prev = prev->previous();
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if (Token::simpleMatch(prev, "}")) {
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if (Token::simpleMatch(prev->link()->tokAt(-2), "} else {"))
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return isReturn(prev) && isReturn(prev->link()->tokAt(-2));
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if (Token::simpleMatch(prev->link()->previous(), ") {") &&
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Token::simpleMatch(prev->link()->linkAt(-1)->previous(), "switch (") &&
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!Token::findsimplematch(prev->link(), "break", prev)) {
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return true;
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}
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} else if (Token::simpleMatch(prev, ";")) {
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// noreturn function
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if (Token::simpleMatch(prev->previous(), ") ;") && Token::Match(prev->linkAt(-1)->tokAt(-2), "[;{}] %name% ("))
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return true;
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// return/goto statement
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prev = prev->previous();
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while (prev && !Token::Match(prev, ";|{|}|return|goto|throw"))
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prev = prev->previous();
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return prev && prev->isName();
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}
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return false;
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}
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static bool isVariableChanged(const Token *start, const Token *end, const unsigned int varid)
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{
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for (const Token *tok = start; tok != end; tok = tok->next()) {
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if (tok->varId() == varid) {
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if (Token::Match(tok, "%name% ="))
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return true;
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if (Token::Match(tok->tokAt(-2), "[(,] & %var% [,)]"))
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return true; // TODO: check if function parameter is const
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const Token *parent = tok->astParent();
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while (Token::Match(parent, ".|::"))
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parent = parent->astParent();
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if (parent && parent->type() == Token::eIncDecOp)
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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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/** Add token value. Return true if value is added. */
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static bool addValue(Token *tok, const ValueFlow::Value &value)
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{
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// if value already exists, don't add it again
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std::list<ValueFlow::Value>::iterator it;
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for (it = tok->values.begin(); it != tok->values.end(); ++it) {
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// different intvalue => continue
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if (it->intvalue != value.intvalue)
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continue;
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// different tokvalue => continue
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if ((it->tokvalue == nullptr) != (value.tokvalue == nullptr))
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continue;
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if ((value.tokvalue != nullptr) && (it->tokvalue != value.tokvalue) && (it->tokvalue->str() != value.tokvalue->str()))
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continue;
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// same value, but old value is inconclusive so replace it
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if (it->inconclusive && !value.inconclusive) {
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*it = value;
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if (it->varId == 0)
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it->varId = tok->varId();
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break;
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}
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// Same value already exists, don't add new value
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return false;
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}
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// Add value
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if (it == tok->values.end()) {
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ValueFlow::Value v(value);
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if (v.varId == 0)
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v.varId = tok->varId();
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tok->values.push_back(v);
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}
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return true;
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}
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/** set ValueFlow value and perform calculations if possible */
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static void setTokenValue(Token* tok, const ValueFlow::Value &value)
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{
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if (!addValue(tok,value))
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return;
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Token *parent = const_cast<Token*>(tok->astParent());
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if (!parent)
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return;
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// Cast..
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if (parent->str() == "(" && tok == parent->link()->next()) {
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setTokenValue(parent,value);
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}
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else if (parent->str() == ":") {
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setTokenValue(parent,value);
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}
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else if (parent->str() == "?" && tok->str() == ":" && tok == parent->astOperand2()) {
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// is condition only depending on 1 variable?
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std::stack<const Token*> tokens;
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tokens.push(parent->astOperand1());
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std::set<unsigned int> variables; // used variables
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while (!tokens.empty()) {
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const Token *t = tokens.top();
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tokens.pop();
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if (!t)
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continue;
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tokens.push(t->astOperand1());
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tokens.push(t->astOperand2());
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if (t->varId()) {
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variables.insert(t->varId());
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if (variables.size() > 1U || value.varId != 0U)
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return;
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} else if (t->str() == "(" && Token::Match(t->previous(), "%name%"))
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return; // function call
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}
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ValueFlow::Value v(value);
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v.conditional = true;
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if (v.valueKind == ValueFlow::Value::Known)
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v.valueKind = ValueFlow::Value::Possible;
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if (!variables.empty())
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v.varId = *(variables.begin());
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setTokenValue(parent, v);
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}
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// Calculations..
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else if (parent->isArithmeticalOp() && parent->astOperand1() && parent->astOperand2()) {
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const bool known = ((parent->astOperand1()->values.size() == 1U &&
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parent->astOperand1()->values.front().valueKind == ValueFlow::Value::ValueKind::Known) ||
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(parent->astOperand2()->values.size() == 1U &&
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parent->astOperand2()->values.front().valueKind == ValueFlow::Value::ValueKind::Known));
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std::list<ValueFlow::Value>::const_iterator value1, value2;
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for (value1 = parent->astOperand1()->values.begin(); value1 != parent->astOperand1()->values.end(); ++value1) {
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for (value2 = parent->astOperand2()->values.begin(); value2 != parent->astOperand2()->values.end(); ++value2) {
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if (known || value1->varId == 0U || value2->varId == 0U ||
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(value1->varId == value2->varId && value1->varvalue == value2->varvalue)) {
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ValueFlow::Value result(0);
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result.condition = value1->condition ? value1->condition : value2->condition;
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result.inconclusive = value1->inconclusive | value2->inconclusive;
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result.varId = (value1->varId != 0U) ? value1->varId : value2->varId;
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result.varvalue = (result.varId == value1->varId) ? value1->intvalue : value2->intvalue;
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if (value1->valueKind == value2->valueKind)
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result.valueKind = value1->valueKind;
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switch (parent->str()[0]) {
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case '+':
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result.intvalue = value1->intvalue + value2->intvalue;
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setTokenValue(parent, result);
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break;
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case '-':
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result.intvalue = value1->intvalue - value2->intvalue;
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setTokenValue(parent, result);
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break;
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case '*':
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result.intvalue = value1->intvalue * value2->intvalue;
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setTokenValue(parent, result);
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break;
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case '/':
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if (value2->intvalue == 0)
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break;
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result.intvalue = value1->intvalue / value2->intvalue;
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setTokenValue(parent, result);
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break;
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case '%':
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if (value2->intvalue == 0)
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break;
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result.intvalue = value1->intvalue % value2->intvalue;
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setTokenValue(parent, result);
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break;
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}
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}
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}
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}
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}
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// !
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else if (parent->str() == "!") {
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std::list<ValueFlow::Value>::const_iterator it;
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for (it = tok->values.begin(); it != tok->values.end(); ++it) {
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if (it->tokvalue)
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continue;
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ValueFlow::Value v(*it);
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v.intvalue = !v.intvalue;
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setTokenValue(parent, v);
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}
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}
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// Array element
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else if (parent->str() == "[" && parent->astOperand1() && parent->astOperand2()) {
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std::list<ValueFlow::Value>::const_iterator value1, value2;
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for (value1 = parent->astOperand1()->values.begin(); value1 != parent->astOperand1()->values.end(); ++value1) {
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if (!value1->tokvalue)
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continue;
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for (value2 = parent->astOperand2()->values.begin(); value2 != parent->astOperand2()->values.end(); ++value2) {
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if (value2->tokvalue)
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continue;
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if (value1->varId == 0U || value2->varId == 0U ||
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(value1->varId == value2->varId && value1->varvalue == value2->varvalue)) {
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ValueFlow::Value result(0);
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result.condition = value1->condition ? value1->condition : value2->condition;
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result.inconclusive = value1->inconclusive | value2->inconclusive;
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result.varId = (value1->varId != 0U) ? value1->varId : value2->varId;
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result.varvalue = (result.varId == value1->varId) ? value1->intvalue : value2->intvalue;
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if (value1->tokvalue->type() == Token::eString) {
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const std::string s = value1->tokvalue->strValue();
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const MathLib::bigint index = value2->intvalue;
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if (index >= 0 && index < s.size()) {
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result.intvalue = s[index];
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setTokenValue(parent, result);
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}
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} else if (value1->tokvalue->str() == "{") {
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MathLib::bigint index = value2->intvalue;
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const Token *element = value1->tokvalue->next();
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while (index > 0 && element->str() != "}") {
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if (element->str() == ",")
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--index;
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if (Token::Match(element, "[{}()[]]"))
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break;
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element = element->next();
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}
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if (Token::Match(element, "%num% [,}]")) {
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result.intvalue = MathLib::toLongNumber(element->str());
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setTokenValue(parent, result);
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}
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}
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}
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}
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|
}
|
|
}
|
|
}
|
|
|
|
static void valueFlowNumber(TokenList *tokenlist)
|
|
{
|
|
for (Token *tok = tokenlist->front(); tok; tok = tok->next()) {
|
|
if (tok->isNumber() && MathLib::isInt(tok->str())) {
|
|
ValueFlow::Value value(MathLib::toLongNumber(tok->str()));
|
|
value.valueKind = ValueFlow::Value::Known;
|
|
setTokenValue(tok, value);
|
|
}
|
|
}
|
|
|
|
if (tokenlist->isCPP()) {
|
|
for (Token *tok = tokenlist->front(); tok; tok = tok->next()) {
|
|
if (tok->isName() && !tok->varId() && Token::Match(tok, "false|true")) {
|
|
ValueFlow::Value value(tok->str() == "true");
|
|
value.valueKind = ValueFlow::Value::Known;
|
|
setTokenValue(tok, value);
|
|
}
|
|
}
|
|
}
|
|
}
|
|
|
|
static void valueFlowString(TokenList *tokenlist)
|
|
{
|
|
for (Token *tok = tokenlist->front(); tok; tok = tok->next()) {
|
|
if (tok->type() == Token::eString) {
|
|
ValueFlow::Value strvalue;
|
|
strvalue.tokvalue = tok;
|
|
strvalue.valueKind = ValueFlow::Value::Known;
|
|
setTokenValue(tok, strvalue);
|
|
}
|
|
}
|
|
}
|
|
|
|
static void valueFlowArray(TokenList *tokenlist)
|
|
{
|
|
std::map<unsigned int, const Token *> constantArrays;
|
|
|
|
for (Token *tok = tokenlist->front(); tok; tok = tok->next()) {
|
|
if (Token::Match(tok, "const %type% %var% [ %num%| ] = {")) {
|
|
const Token *vartok = tok->tokAt(2);
|
|
const Token *rhstok = vartok->next()->link()->tokAt(2);
|
|
constantArrays[vartok->varId()] = rhstok;
|
|
tok = rhstok->link();
|
|
}
|
|
|
|
if (Token::Match(tok, "const char %var% [ %num%| ] = %str% ;")) {
|
|
const Token *vartok = tok->tokAt(2);
|
|
const Token *strtok = vartok->next()->link()->tokAt(2);
|
|
constantArrays[vartok->varId()] = strtok;
|
|
tok = strtok->next();
|
|
}
|
|
|
|
if (tok->varId() > 0U) {
|
|
const std::map<unsigned int, const Token *>::const_iterator it = constantArrays.find(tok->varId());
|
|
if (it != constantArrays.end()) {
|
|
ValueFlow::Value value;
|
|
value.tokvalue = it->second;
|
|
setTokenValue(tok, value);
|
|
}
|
|
}
|
|
}
|
|
}
|
|
|
|
static void valueFlowPointerAlias(TokenList *tokenlist)
|
|
{
|
|
for (Token *tok = tokenlist->front(); tok; tok = tok->next()) {
|
|
// not address of
|
|
if (tok->str() != "&" || tok->astOperand2())
|
|
continue;
|
|
|
|
// parent should be a '='
|
|
if (!Token::simpleMatch(tok->astParent(), "="))
|
|
continue;
|
|
|
|
// child should be some buffer or variable
|
|
if (!Token::Match(tok->astOperand1(), "%name%|.|[|;"))
|
|
continue;
|
|
|
|
ValueFlow::Value value;
|
|
value.tokvalue = tok;
|
|
setTokenValue(tok, value);
|
|
}
|
|
}
|
|
|
|
static void valueFlowBitAnd(TokenList *tokenlist)
|
|
{
|
|
for (Token *tok = tokenlist->front(); tok; tok = tok->next()) {
|
|
if (tok->str() != "&")
|
|
continue;
|
|
|
|
if (!tok->astOperand1() || !tok->astOperand2())
|
|
continue;
|
|
|
|
MathLib::bigint number;
|
|
if (MathLib::isInt(tok->astOperand1()->str()))
|
|
number = MathLib::toLongNumber(tok->astOperand1()->str());
|
|
else if (MathLib::isInt(tok->astOperand2()->str()))
|
|
number = MathLib::toLongNumber(tok->astOperand2()->str());
|
|
else
|
|
continue;
|
|
|
|
int bit = 0;
|
|
while (bit <= 60 && ((1LL<<bit) < number))
|
|
++bit;
|
|
|
|
if ((1LL<<bit) == number) {
|
|
setTokenValue(tok, ValueFlow::Value(0));
|
|
setTokenValue(tok, ValueFlow::Value(number));
|
|
}
|
|
}
|
|
}
|
|
|
|
static void valueFlowReverse(TokenList *tokenlist,
|
|
Token *tok,
|
|
const Token * const varToken,
|
|
ValueFlow::Value val,
|
|
ValueFlow::Value val2,
|
|
ErrorLogger *errorLogger,
|
|
const Settings *settings)
|
|
{
|
|
const MathLib::bigint num = val.intvalue;
|
|
const Variable * const var = varToken->variable();
|
|
const unsigned int varid = varToken->varId();
|
|
const Token * const startToken = var->nameToken();
|
|
|
|
for (Token *tok2 = tok->previous(); ; tok2 = tok2->previous()) {
|
|
if (!tok2 ||
|
|
tok2 == startToken ||
|
|
(tok2->str() == "{" && tok2->scope()->type == Scope::ScopeType::eFunction)) {
|
|
break;
|
|
}
|
|
|
|
if (tok2->varId() == varid) {
|
|
// bailout: assignment
|
|
if (Token::Match(tok2->previous(), "!!* %name% =")) {
|
|
if (settings->debugwarnings)
|
|
bailout(tokenlist, errorLogger, tok2, "assignment of " + tok2->str());
|
|
break;
|
|
}
|
|
|
|
// increment/decrement
|
|
if (Token::Match(tok2->previous(), "[;{}] %name% ++|-- ;"))
|
|
val.intvalue += (tok2->strAt(1)=="++") ? -1 : 1;
|
|
else if (Token::Match(tok2->tokAt(-2), "[;{}] ++|-- %name% ;"))
|
|
val.intvalue += (tok2->strAt(-1)=="++") ? -1 : 1;
|
|
else if (Token::Match(tok2->previous(), "++|-- %name%") || Token::Match(tok2, "%name% ++|--")) {
|
|
if (settings->debugwarnings)
|
|
bailout(tokenlist, errorLogger, tok2, "increment/decrement of " + tok2->str());
|
|
break;
|
|
}
|
|
|
|
// bailout: variable is used in rhs in assignment to itself
|
|
if (bailoutSelfAssignment(tok2)) {
|
|
if (settings->debugwarnings)
|
|
bailout(tokenlist, errorLogger, tok2, "variable " + tok2->str() + " is used in rhs in assignment to itself");
|
|
break;
|
|
}
|
|
|
|
if (Token::Match(tok2->previous(), "sizeof|.")) {
|
|
const Token *prev = tok2->previous();
|
|
while (Token::Match(prev,"%name%|.") && prev->str() != "sizeof")
|
|
prev = prev->previous();
|
|
if (prev && prev->str() == "sizeof")
|
|
continue;
|
|
}
|
|
|
|
// assigned by subfunction?
|
|
bool inconclusive = false;
|
|
if (bailoutFunctionPar(tok2,val2.condition ? val2 : val, settings, &inconclusive)) {
|
|
if (settings->debugwarnings)
|
|
bailout(tokenlist, errorLogger, tok2, "possible assignment of " + tok2->str() + " by subfunction");
|
|
break;
|
|
}
|
|
val.inconclusive |= inconclusive;
|
|
val2.inconclusive |= inconclusive;
|
|
|
|
// skip if variable is conditionally used in ?: expression
|
|
if (const Token *parent = skipValueInConditionalExpression(tok2)) {
|
|
if (settings->debugwarnings)
|
|
bailout(tokenlist,
|
|
errorLogger,
|
|
tok2,
|
|
"no simplification of " + tok2->str() + " within " + (Token::Match(parent,"[?:]") ? "?:" : parent->str()) + " expression");
|
|
continue;
|
|
}
|
|
|
|
setTokenValue(tok2, val);
|
|
if (val2.condition)
|
|
setTokenValue(tok2,val2);
|
|
if (var && tok2 == var->nameToken())
|
|
break;
|
|
}
|
|
|
|
// skip sizeof..
|
|
if (tok2->str() == ")" && Token::Match(tok2->link()->previous(), "typeof|sizeof ("))
|
|
tok2 = tok2->link();
|
|
|
|
// goto label
|
|
if (Token::Match(tok2, "[;{}] %name% :")) {
|
|
if (settings->debugwarnings)
|
|
bailout(tokenlist, errorLogger, tok2->next(), "variable " + var->name() + " stopping on goto label");
|
|
break;
|
|
}
|
|
|
|
if (tok2->str() == "}") {
|
|
const Token *vartok = Token::findmatch(tok2->link(), "%varid%", tok2, varid);
|
|
while (Token::Match(vartok, "%name% = %num% ;") && !vartok->tokAt(2)->getValue(num))
|
|
vartok = Token::findmatch(vartok->next(), "%varid%", tok2, varid);
|
|
if (vartok) {
|
|
if (settings->debugwarnings) {
|
|
std::string errmsg = "variable ";
|
|
if (var)
|
|
errmsg += var->name() + " ";
|
|
errmsg += "stopping on }";
|
|
bailout(tokenlist, errorLogger, tok2, errmsg);
|
|
}
|
|
break;
|
|
} else {
|
|
tok2 = tok2->link();
|
|
}
|
|
} else if (tok2->str() == "{") {
|
|
// if variable is assigned in loop don't look before the loop
|
|
if (tok2->previous() &&
|
|
(Token::simpleMatch(tok2->previous(), "do") ||
|
|
(tok2->strAt(-1) == ")" && Token::Match(tok2->linkAt(-1)->previous(), "for|while (")))) {
|
|
|
|
const Token *start = tok2;
|
|
const Token *end = start->link();
|
|
if (isVariableChanged(start,end,varid)) {
|
|
if (settings->debugwarnings)
|
|
bailout(tokenlist, errorLogger, tok2, "variable " + var->name() + " is assigned in loop. so valueflow analysis bailout when start of loop is reached.");
|
|
break;
|
|
}
|
|
}
|
|
|
|
// Global variable : stop when leaving the function scope
|
|
if (!var->isLocal()) {
|
|
if (!Token::Match(tok2->previous(), ")|else|do {"))
|
|
break;
|
|
if (Token::simpleMatch(tok2->previous(), ") {") &&
|
|
!Token::Match(tok2->linkAt(-1)->previous(), "if|for|while ("))
|
|
break;
|
|
}
|
|
} else if (tok2->str() == ";") {
|
|
const Token *parent = tok2->previous();
|
|
while (parent && !Token::Match(parent, "return|break|continue|goto"))
|
|
parent = parent->astParent();
|
|
// reaching a break/continue/return
|
|
if (parent) {
|
|
if (settings->debugwarnings)
|
|
bailout(tokenlist, errorLogger, tok2, "variable " + var->name() + " stopping on " + parent->str());
|
|
break;
|
|
}
|
|
}
|
|
}
|
|
|
|
}
|
|
|
|
static void valueFlowBeforeCondition(TokenList *tokenlist, SymbolDatabase *symboldatabase, ErrorLogger *errorLogger, const Settings *settings)
|
|
{
|
|
const std::size_t functions = symboldatabase->functionScopes.size();
|
|
for (std::size_t i = 0; i < functions; ++i) {
|
|
const Scope * scope = symboldatabase->functionScopes[i];
|
|
for (Token* tok = const_cast<Token*>(scope->classStart); tok != scope->classEnd; tok = tok->next()) {
|
|
MathLib::bigint num = 0;
|
|
const Token *vartok = nullptr;
|
|
if (tok->isComparisonOp() && tok->astOperand1() && tok->astOperand2()) {
|
|
if (tok->astOperand1()->isName() && tok->astOperand2()->isNumber()) {
|
|
vartok = tok->astOperand1();
|
|
num = MathLib::toLongNumber(tok->astOperand2()->str());
|
|
} else if (tok->astOperand1()->isNumber() && tok->astOperand2()->isName()) {
|
|
vartok = tok->astOperand2();
|
|
num = MathLib::toLongNumber(tok->astOperand1()->str());
|
|
} else {
|
|
continue;
|
|
}
|
|
} else if (Token::Match(tok->previous(), "if|while ( %name% %oror%|&&|)") ||
|
|
Token::Match(tok, "%oror%|&& %name% %oror%|&&|)")) {
|
|
vartok = tok->next();
|
|
num = 0;
|
|
} else if (tok->str() == "!" && tok->astOperand1() && tok->astOperand1()->isName()) {
|
|
vartok = tok->astOperand1();
|
|
num = 0;
|
|
} else {
|
|
continue;
|
|
}
|
|
|
|
unsigned int varid = vartok->varId();
|
|
const Variable * const var = vartok->variable();
|
|
|
|
if (varid == 0U || !var)
|
|
continue;
|
|
|
|
// bailout: global non-const variables
|
|
if (!(var->isLocal() || var->isArgument()) && !var->isConst()) {
|
|
if (settings->debugwarnings)
|
|
bailout(tokenlist, errorLogger, tok, "global variable " + var->name());
|
|
continue;
|
|
}
|
|
|
|
// bailout: for/while-condition, variable is changed in while loop
|
|
for (const Token *tok2 = tok; tok2; tok2 = tok2->astParent()) {
|
|
if (tok2->astParent() || tok2->str() != "(" || !Token::simpleMatch(tok2->link(), ") {"))
|
|
continue;
|
|
|
|
// Variable changed in 3rd for-expression
|
|
if (Token::simpleMatch(tok2->previous(), "for (")) {
|
|
if (tok2->astOperand2() && isVariableChanged(tok2->astOperand2()->astOperand2(), tok2->link(), varid)) {
|
|
varid = 0U;
|
|
if (settings->debugwarnings)
|
|
bailout(tokenlist, errorLogger, tok, "variable " + var->name() + " used in loop");
|
|
}
|
|
}
|
|
|
|
// Variable changed in loop code
|
|
if (Token::Match(tok2->previous(), "for|while (")) {
|
|
const Token * const start = tok2->link()->next();
|
|
const Token * const end = start->link();
|
|
|
|
if (isVariableChanged(start,end,varid)) {
|
|
varid = 0U;
|
|
if (settings->debugwarnings)
|
|
bailout(tokenlist, errorLogger, tok, "variable " + var->name() + " used in loop");
|
|
}
|
|
}
|
|
|
|
// if,macro => bailout
|
|
else if (Token::simpleMatch(tok2->previous(), "if (") && tok2->previous()->isExpandedMacro()) {
|
|
varid = 0U;
|
|
if (settings->debugwarnings)
|
|
bailout(tokenlist, errorLogger, tok, "variable " + var->name() + ", condition is defined in macro");
|
|
}
|
|
}
|
|
if (varid == 0U)
|
|
continue;
|
|
|
|
// extra logic for unsigned variables 'i>=1' => possible value can also be 0
|
|
ValueFlow::Value val(tok, num);
|
|
val.varId = varid;
|
|
if (Token::Match(tok, "<|>")) {
|
|
if (num != 0)
|
|
continue;
|
|
if (!var->typeStartToken()->isUnsigned())
|
|
continue;
|
|
}
|
|
ValueFlow::Value val2;
|
|
if (num==1U && Token::Match(tok,"<=|>=")) {
|
|
if (var->typeStartToken()->isUnsigned()) {
|
|
val2 = ValueFlow::Value(tok,0);
|
|
val2.varId = varid;
|
|
}
|
|
}
|
|
valueFlowReverse(tokenlist,
|
|
tok,
|
|
vartok,
|
|
val,
|
|
val2,
|
|
errorLogger,
|
|
settings);
|
|
|
|
}
|
|
}
|
|
}
|
|
|
|
static void removeValues(std::list<ValueFlow::Value> &values, const std::list<ValueFlow::Value> &valuesToRemove)
|
|
{
|
|
for (std::list<ValueFlow::Value>::iterator it = values.begin(); it != values.end();) {
|
|
bool found = false;
|
|
for (std::list<ValueFlow::Value>::const_iterator it2 = valuesToRemove.begin(); it2 != valuesToRemove.end(); ++it2) {
|
|
if (it->intvalue == it2->intvalue) {
|
|
found = true;
|
|
break;
|
|
}
|
|
}
|
|
if (found)
|
|
values.erase(it++);
|
|
else
|
|
++it;
|
|
}
|
|
}
|
|
|
|
static void valueFlowAST(Token *tok, unsigned int varid, const ValueFlow::Value &value)
|
|
{
|
|
if (!tok)
|
|
return;
|
|
if (tok->varId() == varid)
|
|
setTokenValue(tok, value);
|
|
valueFlowAST(const_cast<Token*>(tok->astOperand1()), varid, value);
|
|
valueFlowAST(const_cast<Token*>(tok->astOperand2()), varid, value);
|
|
}
|
|
|
|
/** if known variable is changed in loop body, change it to a possible value */
|
|
static void handleKnownValuesInLoop(const Token *loopBodyStart,
|
|
std::list<ValueFlow::Value> *values,
|
|
unsigned int varid)
|
|
{
|
|
bool isChanged = false;
|
|
for (std::list<ValueFlow::Value>::iterator it = values->begin(); it != values->end(); ++it) {
|
|
if (it->valueKind == ValueFlow::Value::Known) {
|
|
if (!isChanged) {
|
|
if (!isVariableChanged(loopBodyStart, loopBodyStart->link(), varid))
|
|
break;
|
|
isChanged = true;
|
|
}
|
|
|
|
it->valueKind = ValueFlow::Value::Possible;
|
|
}
|
|
}
|
|
}
|
|
|
|
static bool valueFlowForward(Token * const startToken,
|
|
const Token * const endToken,
|
|
const Variable * const var,
|
|
const unsigned int varid,
|
|
std::list<ValueFlow::Value> values,
|
|
const bool constValue,
|
|
TokenList * const tokenlist,
|
|
ErrorLogger * const errorLogger,
|
|
const Settings * const settings)
|
|
{
|
|
int indentlevel = 0;
|
|
unsigned int number_of_if = 0;
|
|
int varusagelevel = -1;
|
|
bool returnStatement = false; // current statement is a return, stop analysis at the ";"
|
|
bool read = false; // is variable value read?
|
|
|
|
for (Token *tok2 = startToken; tok2 && tok2 != endToken; tok2 = tok2->next()) {
|
|
if (indentlevel >= 0 && tok2->str() == "{")
|
|
++indentlevel;
|
|
else if (indentlevel >= 0 && tok2->str() == "}") {
|
|
--indentlevel;
|
|
if (indentlevel <= 0 && isReturn(tok2) && Token::Match(tok2->link()->previous(), "else|) {")) {
|
|
const Token *condition = tok2->link();
|
|
const bool iselse = Token::simpleMatch(condition->tokAt(-2), "} else {");
|
|
if (iselse)
|
|
condition = condition->linkAt(-2);
|
|
if (condition && Token::simpleMatch(condition->previous(), ") {"))
|
|
condition = condition->linkAt(-1)->astOperand2();
|
|
else
|
|
condition = nullptr;
|
|
if (!condition) {
|
|
if (settings->debugwarnings)
|
|
bailout(tokenlist, errorLogger, tok2, "variable " + var->name() + " valueFlowForward, bailing out since it's unknown if conditional return is executed");
|
|
return false;
|
|
}
|
|
|
|
bool bailoutflag = false;
|
|
for (std::list<ValueFlow::Value>::const_iterator it = values.begin(); it != values.end(); ++it) {
|
|
if (!iselse && conditionIsTrue(condition, getProgramMemory(condition->astParent(), varid, *it))) {
|
|
bailoutflag = true;
|
|
break;
|
|
}
|
|
if (iselse && conditionIsFalse(condition, getProgramMemory(condition->astParent(), varid, *it))) {
|
|
bailoutflag = true;
|
|
break;
|
|
}
|
|
}
|
|
if (bailoutflag) {
|
|
if (settings->debugwarnings)
|
|
bailout(tokenlist, errorLogger, tok2, "variable " + var->name() + " valueFlowForward, conditional return is assumed to be executed");
|
|
return false;
|
|
}
|
|
}
|
|
}
|
|
|
|
if (Token::Match(tok2, "sizeof|typeof|typeid ("))
|
|
tok2 = tok2->linkAt(1);
|
|
|
|
else if (Token::simpleMatch(tok2, "else {")) {
|
|
// Should scope be skipped because variable value is checked?
|
|
bool skipelse = false;
|
|
const Token *condition = tok2->linkAt(-1);
|
|
condition = condition ? condition->linkAt(-1) : nullptr;
|
|
condition = condition ? condition->astOperand2() : nullptr;
|
|
for (std::list<ValueFlow::Value>::iterator it = values.begin(); it != values.end(); ++it) {
|
|
if (conditionIsTrue(condition, getProgramMemory(tok2, varid, *it))) {
|
|
skipelse = true;
|
|
break;
|
|
}
|
|
}
|
|
if (skipelse) {
|
|
tok2 = tok2->linkAt(1);
|
|
continue;
|
|
}
|
|
}
|
|
|
|
else if (Token::simpleMatch(tok2, "do {")) {
|
|
handleKnownValuesInLoop(tok2->next(), &values, varid);
|
|
}
|
|
|
|
// conditional block of code that assigns variable..
|
|
else if (Token::Match(tok2, "%name% (") && Token::simpleMatch(tok2->linkAt(1), ") {")) {
|
|
// is variable changed in condition?
|
|
if (isVariableChanged(tok2->next(), tok2->next()->link(), varid)) {
|
|
if (settings->debugwarnings)
|
|
bailout(tokenlist, errorLogger, tok2, "variable " + var->name() + " valueFlowForward, assignment in condition");
|
|
return false;
|
|
}
|
|
|
|
// if known variable is changed in loop body, change it to a possible value..
|
|
handleKnownValuesInLoop(tok2->linkAt(1)->next(), &values, varid);
|
|
|
|
// Set values in condition
|
|
for (Token* tok3 = tok2->tokAt(2); tok3 != tok2->next()->link(); tok3 = tok3->next()) {
|
|
if (tok3->varId() == varid) {
|
|
for (std::list<ValueFlow::Value>::const_iterator it = values.begin(); it != values.end(); ++it)
|
|
setTokenValue(tok3, *it);
|
|
} else if (Token::Match(tok3, "%oror%|&&|?")) {
|
|
break;
|
|
}
|
|
}
|
|
|
|
// Should scope be skipped because variable value is checked?
|
|
std::list<ValueFlow::Value> truevalues;
|
|
for (std::list<ValueFlow::Value>::const_iterator it = values.begin(); it != values.end(); ++it) {
|
|
if (!conditionIsFalse(tok2->next()->astOperand2(), getProgramMemory(tok2, varid, *it)))
|
|
truevalues.push_back(*it);
|
|
}
|
|
if (truevalues.size() != values.size()) {
|
|
// '{'
|
|
Token * const startToken1 = tok2->linkAt(1)->next();
|
|
|
|
valueFlowForward(startToken1->next(),
|
|
startToken1->link(),
|
|
var,
|
|
varid,
|
|
truevalues,
|
|
constValue,
|
|
tokenlist,
|
|
errorLogger,
|
|
settings);
|
|
|
|
if (isVariableChanged(startToken1, startToken1->link(), varid))
|
|
removeValues(values, truevalues);
|
|
|
|
// goto '}'
|
|
tok2 = startToken1->link();
|
|
continue;
|
|
}
|
|
|
|
Token * const start = tok2->linkAt(1)->next();
|
|
Token * const end = start->link();
|
|
bool varusage = (indentlevel >= 0 && constValue && number_of_if == 0U) ?
|
|
isVariableChanged(start,end,varid) :
|
|
(nullptr != Token::findmatch(start, "%varid%", end, varid));
|
|
if (!read) {
|
|
read = bool(nullptr != Token::findmatch(tok2, "%varid% !!=", end, varid));
|
|
}
|
|
if (varusage) {
|
|
varusagelevel = indentlevel;
|
|
|
|
if (indentlevel < 0 && tok2->str() == "switch")
|
|
return false;
|
|
|
|
// TODO: don't check noreturn scopes
|
|
if (read && (number_of_if > 0U || Token::findmatch(tok2, "%varid%", start, varid))) {
|
|
// Set values in condition
|
|
const Token * const condend = tok2->linkAt(1);
|
|
for (Token *condtok = tok2; condtok != condend; condtok = condtok->next()) {
|
|
if (condtok->varId() == varid) {
|
|
std::list<ValueFlow::Value>::const_iterator it;
|
|
for (it = values.begin(); it != values.end(); ++it)
|
|
setTokenValue(condtok, *it);
|
|
}
|
|
if (Token::Match(condtok, "%oror%|&&"))
|
|
break;
|
|
}
|
|
if (settings->debugwarnings)
|
|
bailout(tokenlist, errorLogger, tok2, "variable " + var->name() + " is assigned in conditional code");
|
|
return false;
|
|
}
|
|
|
|
if (var->isStatic()) {
|
|
if (settings->debugwarnings)
|
|
bailout(tokenlist, errorLogger, tok2, "variable " + var->name() + " bailout when conditional code that contains var is seen");
|
|
return false;
|
|
}
|
|
|
|
// Remove conditional values
|
|
std::list<ValueFlow::Value>::iterator it;
|
|
for (it = values.begin(); it != values.end();) {
|
|
if (it->condition || it->conditional)
|
|
values.erase(it++);
|
|
else {
|
|
if (it->valueKind == ValueFlow::Value::Known)
|
|
it->valueKind = ValueFlow::Value::Possible;
|
|
++it;
|
|
}
|
|
}
|
|
}
|
|
|
|
// stop after conditional noreturn scopes that are executed
|
|
if (isReturn(end)) {
|
|
std::list<ValueFlow::Value>::iterator it;
|
|
for (it = values.begin(); it != values.end();) {
|
|
if (conditionIsTrue(tok2->next()->astOperand2(), getProgramMemory(tok2, varid, *it)))
|
|
values.erase(it++);
|
|
else
|
|
++it;
|
|
}
|
|
if (values.empty())
|
|
return false;
|
|
}
|
|
|
|
// noreturn scopes..
|
|
if ((number_of_if > 0 || Token::findmatch(tok2, "%varid%", start, varid)) &&
|
|
(Token::findmatch(start, "return|continue|break|throw", end) ||
|
|
(Token::simpleMatch(end,"} else {") && Token::findmatch(end, "return|continue|break|throw", end->linkAt(2))))) {
|
|
if (settings->debugwarnings)
|
|
bailout(tokenlist, errorLogger, tok2, "variable " + var->name() + ". noreturn conditional scope.");
|
|
return false;
|
|
}
|
|
|
|
if (isVariableChanged(start, end, varid)) {
|
|
if ((!read || number_of_if == 0) &&
|
|
Token::simpleMatch(tok2, "if (") &&
|
|
!(Token::simpleMatch(end, "} else {") &&
|
|
(Token::findmatch(end, "%varid%", end->linkAt(2), varid) ||
|
|
Token::findmatch(end, "return|continue|break|throw", end->linkAt(2))))) {
|
|
++number_of_if;
|
|
tok2 = end;
|
|
} else {
|
|
bool bail = true;
|
|
|
|
// loop that conditionally set variable and then break => either loop condition is
|
|
// redundant or the variable can be unchanged after the loop.
|
|
bool loopCondition = false;
|
|
if (Token::simpleMatch(tok2, "while (") && Token::Match(tok2->next()->astOperand2(), "%op%"))
|
|
loopCondition = true;
|
|
else if (Token::simpleMatch(tok2, "for (") &&
|
|
Token::simpleMatch(tok2->next()->astOperand2(), ";") &&
|
|
Token::simpleMatch(tok2->next()->astOperand2()->astOperand2(), ";") &&
|
|
Token::Match(tok2->next()->astOperand2()->astOperand2()->astOperand1(), "%op%"))
|
|
loopCondition = true;
|
|
if (loopCondition) {
|
|
const Token *tok3 = Token::findmatch(start, "%varid%", end, varid);
|
|
if (Token::Match(tok3, "%varid% =", varid) &&
|
|
tok3->scope()->classEnd &&
|
|
Token::Match(tok3->scope()->classEnd->tokAt(-3), "[;}] break ;") &&
|
|
!Token::findmatch(tok3->next(), "%varid%", end, varid)) {
|
|
bail = false;
|
|
tok2 = end;
|
|
}
|
|
}
|
|
|
|
if (bail) {
|
|
if (settings->debugwarnings)
|
|
bailout(tokenlist, errorLogger, tok2, "variable " + var->name() + " is assigned in conditional code");
|
|
return false;
|
|
}
|
|
}
|
|
}
|
|
}
|
|
|
|
else if (tok2->str() == "}" && indentlevel == varusagelevel) {
|
|
++number_of_if;
|
|
|
|
// Set "conditional" flag for all values
|
|
std::list<ValueFlow::Value>::iterator it;
|
|
for (it = values.begin(); it != values.end(); ++it) {
|
|
it->conditional = true;
|
|
if (it->valueKind == ValueFlow::Value::Known)
|
|
it->valueKind = ValueFlow::Value::Possible;
|
|
}
|
|
|
|
if (Token::simpleMatch(tok2,"} else {"))
|
|
tok2 = tok2->linkAt(2);
|
|
}
|
|
|
|
else if (indentlevel <= 0 && Token::Match(tok2, "break|continue|goto")) {
|
|
if (tok2->str() == "break") {
|
|
const Scope *scope = tok2->scope();
|
|
if (scope && scope->type == Scope::eSwitch) {
|
|
tok2 = const_cast<Token *>(scope->classEnd);
|
|
--indentlevel;
|
|
for (std::list<ValueFlow::Value>::iterator it = values.begin(); it != values.end(); ++it) {
|
|
if (it->valueKind == ValueFlow::Value::ValueKind::Known)
|
|
it->valueKind = ValueFlow::Value::ValueKind::Possible;
|
|
}
|
|
continue;
|
|
}
|
|
}
|
|
if (settings->debugwarnings)
|
|
bailout(tokenlist, errorLogger, tok2, "variable " + var->name() + ". noreturn conditional scope.");
|
|
return false;
|
|
}
|
|
|
|
else if (indentlevel <= 0 && Token::Match(tok2, "return|throw"))
|
|
returnStatement = true;
|
|
|
|
else if (returnStatement && tok2->str() == ";")
|
|
return false;
|
|
|
|
// If a ? is seen and it's known that the condition is true/false..
|
|
else if (tok2->str() == "?") {
|
|
const Token *condition = tok2->astOperand1();
|
|
if (!condition) // Ticket #6713
|
|
continue;
|
|
std::list<ValueFlow::Value>::const_iterator it;
|
|
for (it = values.begin(); it != values.end(); ++it) {
|
|
const std::map<unsigned int, MathLib::bigint> programMemory(getProgramMemory(tok2, varid, *it));
|
|
if (conditionIsTrue(condition, programMemory))
|
|
valueFlowAST(const_cast<Token*>(tok2->astOperand2()->astOperand1()), varid, *it);
|
|
else if (conditionIsFalse(condition, programMemory))
|
|
valueFlowAST(const_cast<Token*>(tok2->astOperand2()->astOperand2()), varid, *it);
|
|
else
|
|
valueFlowAST(const_cast<Token*>(tok2->astOperand2()), varid, *it);
|
|
}
|
|
// Skip conditional expressions..
|
|
while (tok2->astOperand1() || tok2->astOperand2()) {
|
|
if (tok2->astOperand2())
|
|
tok2 = const_cast<Token*>(tok2->astOperand2());
|
|
else if (tok2->isUnaryPreOp())
|
|
tok2 = const_cast<Token*>(tok2->astOperand1());
|
|
else
|
|
break;
|
|
}
|
|
tok2 = tok2->next();
|
|
}
|
|
|
|
if (tok2->varId() == varid) {
|
|
// bailout: assignment
|
|
if (Token::Match(tok2->previous(), "!!* %name% %op%") && tok2->next()->isAssignmentOp()) {
|
|
// simplify rhs
|
|
for (Token *tok3 = tok2->tokAt(2); tok3; tok3 = tok3->next()) {
|
|
if (tok3->varId() == varid) {
|
|
std::list<ValueFlow::Value>::const_iterator it;
|
|
for (it = values.begin(); it != values.end(); ++it)
|
|
setTokenValue(tok3, *it);
|
|
} else if (Token::Match(tok3, "++|--|?|:|;"))
|
|
break;
|
|
}
|
|
if (settings->debugwarnings)
|
|
bailout(tokenlist, errorLogger, tok2, "assignment of " + tok2->str());
|
|
return false;
|
|
}
|
|
|
|
// bailout: possible assignment using >>
|
|
if (Token::Match(tok2->previous(), ">> %name% >>|;")) {
|
|
const Token *parent = tok2->previous();
|
|
do {
|
|
parent = parent->astParent();
|
|
} while (Token::simpleMatch(parent, ">>"));
|
|
if (!parent) {
|
|
if (settings->debugwarnings)
|
|
bailout(tokenlist, errorLogger, tok2, "Possible assignment of " + tok2->str() + " using >>");
|
|
return false;
|
|
}
|
|
}
|
|
|
|
// skip if variable is conditionally used in ?: expression
|
|
if (const Token *parent = skipValueInConditionalExpression(tok2)) {
|
|
if (settings->debugwarnings)
|
|
bailout(tokenlist,
|
|
errorLogger,
|
|
tok2,
|
|
"no simplification of " + tok2->str() + " within " + (Token::Match(parent,"[?:]") ? "?:" : parent->str()) + " expression");
|
|
const Token *astTop = parent->astTop();
|
|
if (Token::simpleMatch(astTop->astOperand1(), "for ("))
|
|
tok2 = const_cast<Token*>(astTop->link());
|
|
continue;
|
|
}
|
|
|
|
{
|
|
// Is variable usage protected by && || ?:
|
|
const Token *tok3 = tok2;
|
|
const Token *parent = tok3->astParent();
|
|
while (parent && !Token::Match(parent, "%oror%|&&|:")) {
|
|
tok3 = parent;
|
|
parent = parent->astParent();
|
|
}
|
|
const bool conditional = parent && (parent->str() == ":" || parent->astOperand2() == tok3);
|
|
|
|
std::list<ValueFlow::Value>::const_iterator it;
|
|
for (it = values.begin(); it != values.end(); ++it) {
|
|
if (!conditional || !it->conditional)
|
|
setTokenValue(tok2, *it);
|
|
}
|
|
}
|
|
|
|
// increment/decrement
|
|
if (Token::Match(tok2->previous(), "++|-- %name%") || Token::Match(tok2, "%name% ++|--")) {
|
|
const bool pre = Token::Match(tok2->previous(), "++|--");
|
|
Token * const op = pre ? tok2->previous() : tok2->next();
|
|
const bool inc = (op->str() == "++");
|
|
std::list<ValueFlow::Value>::iterator it;
|
|
// Erase values that are not int values..
|
|
for (it = values.begin(); it != values.end();) {
|
|
if (it->tokvalue)
|
|
it = values.erase(it);
|
|
else
|
|
++it;
|
|
}
|
|
if (values.empty()) {
|
|
if (settings->debugwarnings)
|
|
bailout(tokenlist, errorLogger, tok2, "increment/decrement of " + tok2->str());
|
|
return false;
|
|
}
|
|
// Perform increment/decrement..
|
|
for (it = values.begin(); it != values.end(); ++it) {
|
|
if (!pre)
|
|
setTokenValue(op, *it);
|
|
it->intvalue += (inc ? 1 : -1);
|
|
if (pre)
|
|
setTokenValue(op, *it);
|
|
}
|
|
}
|
|
|
|
// bailout if address of var is taken..
|
|
if (tok2->astParent() && tok2->astParent()->str() == "&" && !tok2->astParent()->astOperand2()) {
|
|
if (settings->debugwarnings)
|
|
bailout(tokenlist, errorLogger, tok2, "Taking address of " + tok2->str());
|
|
return false;
|
|
}
|
|
|
|
// bailout if reference is created..
|
|
if (tok2->astParent() && Token::Match(tok2->astParent()->tokAt(-2), "& %name% =")) {
|
|
if (settings->debugwarnings)
|
|
bailout(tokenlist, errorLogger, tok2, "Reference of " + tok2->str());
|
|
return false;
|
|
}
|
|
|
|
// assigned by subfunction?
|
|
bool inconclusive = false;
|
|
if (bailoutFunctionPar(tok2, ValueFlow::Value(), settings, &inconclusive)) {
|
|
if (settings->debugwarnings)
|
|
bailout(tokenlist, errorLogger, tok2, "possible assignment of " + tok2->str() + " by subfunction");
|
|
return false;
|
|
}
|
|
if (inconclusive) {
|
|
std::list<ValueFlow::Value>::iterator it;
|
|
for (it = values.begin(); it != values.end(); ++it)
|
|
it->inconclusive = true;
|
|
}
|
|
}
|
|
}
|
|
return true;
|
|
}
|
|
|
|
static void valueFlowAfterAssign(TokenList *tokenlist, SymbolDatabase* symboldatabase, ErrorLogger *errorLogger, const Settings *settings)
|
|
{
|
|
const std::size_t functions = symboldatabase->functionScopes.size();
|
|
for (std::size_t i = 0; i < functions; ++i) {
|
|
const Scope * scope = symboldatabase->functionScopes[i];
|
|
for (Token* tok = const_cast<Token*>(scope->classStart); tok != scope->classEnd; tok = tok->next()) {
|
|
// Assignment
|
|
if ((tok->str() != "=") || (tok->astParent()))
|
|
continue;
|
|
|
|
// Lhs should be a variable
|
|
if (!tok->astOperand1() || !tok->astOperand1()->varId())
|
|
continue;
|
|
const unsigned int varid = tok->astOperand1()->varId();
|
|
const Variable *var = tok->astOperand1()->variable();
|
|
if (!var || (!var->isLocal() && !var->isArgument()))
|
|
continue;
|
|
|
|
const Token * const endOfVarScope = var->typeStartToken()->scope()->classEnd;
|
|
|
|
// Rhs values..
|
|
if (!tok->astOperand2() || tok->astOperand2()->values.empty())
|
|
continue;
|
|
|
|
std::list<ValueFlow::Value> values = tok->astOperand2()->values;
|
|
const bool constValue = tok->astOperand2()->isNumber();
|
|
|
|
// Static variable initialisation?
|
|
if (var->isStatic() && var->nameToken() == tok->astOperand1()) {
|
|
for (std::list<ValueFlow::Value>::iterator it = values.begin(); it != values.end(); ++it) {
|
|
if (it->valueKind == ValueFlow::Value::ValueKind::Known)
|
|
it->valueKind = ValueFlow::Value::ValueKind::Possible;
|
|
}
|
|
}
|
|
|
|
valueFlowForward(tok, endOfVarScope, var, varid, values, constValue, tokenlist, errorLogger, settings);
|
|
}
|
|
}
|
|
}
|
|
|
|
static void valueFlowAfterCondition(TokenList *tokenlist, SymbolDatabase* symboldatabase, ErrorLogger *errorLogger, const Settings *settings)
|
|
{
|
|
const std::size_t functions = symboldatabase->functionScopes.size();
|
|
for (std::size_t i = 0; i < functions; ++i) {
|
|
const Scope * scope = symboldatabase->functionScopes[i];
|
|
for (Token* tok = const_cast<Token*>(scope->classStart); tok != scope->classEnd; tok = tok->next()) {
|
|
const Token *vartok, *numtok;
|
|
|
|
// Comparison
|
|
if (Token::Match(tok, "==|!=|>=|<=")) {
|
|
if (!tok->astOperand1() || !tok->astOperand2())
|
|
continue;
|
|
if (tok->astOperand1()->isNumber()) {
|
|
numtok = tok->astOperand1();
|
|
vartok = tok->astOperand2();
|
|
} else {
|
|
numtok = tok->astOperand2();
|
|
vartok = tok->astOperand1();
|
|
}
|
|
if (vartok->str() == "=" && vartok->astOperand1() && vartok->astOperand2())
|
|
vartok = vartok->astOperand1();
|
|
if (!vartok->isName() || !numtok->isNumber() || !MathLib::isInt(numtok->str()))
|
|
continue;
|
|
} else if (tok->str() == "!") {
|
|
vartok = tok->astOperand1();
|
|
numtok = nullptr;
|
|
if (!vartok || !vartok->isName())
|
|
continue;
|
|
|
|
} else if (tok->isName() &&
|
|
(Token::Match(tok->astParent(), "%oror%|&&") ||
|
|
Token::Match(tok->tokAt(-2), "if|while ( %var% [)=]"))) {
|
|
vartok = tok;
|
|
numtok = nullptr;
|
|
|
|
} else {
|
|
continue;
|
|
}
|
|
|
|
const unsigned int varid = vartok->varId();
|
|
if (varid == 0U)
|
|
continue;
|
|
const Variable *var = vartok->variable();
|
|
if (!var || !(var->isLocal() || var->isArgument()))
|
|
continue;
|
|
std::list<ValueFlow::Value> values;
|
|
values.push_back(ValueFlow::Value(tok, numtok ? MathLib::toLongNumber(numtok->str()) : 0LL));
|
|
|
|
if (Token::Match(tok->astParent(), "%oror%|&&")) {
|
|
Token *parent = const_cast<Token*>(tok->astParent());
|
|
const std::string &op(parent->str());
|
|
|
|
if (parent->astOperand1() == tok &&
|
|
((op == "&&" && Token::Match(tok, "==|>=|<=|!")) ||
|
|
(op == "||" && Token::Match(tok, "%name%|!=")))) {
|
|
for (; parent && parent->str() == op; parent = const_cast<Token*>(parent->astParent())) {
|
|
std::stack<Token *> tokens;
|
|
tokens.push(const_cast<Token*>(parent->astOperand2()));
|
|
bool assign = false;
|
|
while (!tokens.empty()) {
|
|
Token *rhstok = tokens.top();
|
|
tokens.pop();
|
|
if (!rhstok)
|
|
continue;
|
|
tokens.push(const_cast<Token*>(rhstok->astOperand1()));
|
|
tokens.push(const_cast<Token*>(rhstok->astOperand2()));
|
|
if (rhstok->varId() == varid)
|
|
setTokenValue(rhstok, values.front());
|
|
if (Token::Match(rhstok, "++|--|=") && Token::Match(rhstok->astOperand1(), "%varid%", varid)) {
|
|
assign = true;
|
|
break;
|
|
}
|
|
}
|
|
if (assign)
|
|
break;
|
|
while (parent->astParent() && parent == parent->astParent()->astOperand2())
|
|
parent = const_cast<Token*>(parent->astParent());
|
|
}
|
|
}
|
|
}
|
|
|
|
const Token *top = tok->astTop();
|
|
if (top && Token::Match(top->previous(), "if|while (") && !top->previous()->isExpandedMacro()) {
|
|
// does condition reassign variable?
|
|
if (tok != top->astOperand2() &&
|
|
Token::Match(top->astOperand2(), "%oror%|&&") &&
|
|
isVariableChanged(top, top->link(), varid)) {
|
|
if (settings->debugwarnings)
|
|
bailout(tokenlist, errorLogger, tok, "assignment in condition");
|
|
continue;
|
|
}
|
|
|
|
// start token of conditional code
|
|
Token *startToken = nullptr;
|
|
|
|
// based on the comparison, should we check the if or while?
|
|
int codeblock = 0;
|
|
if (Token::Match(tok, "==|>=|<=|!"))
|
|
codeblock = 1;
|
|
else if (Token::Match(tok, "%name%|!="))
|
|
codeblock = 2;
|
|
|
|
// determine startToken based on codeblock
|
|
if (codeblock > 0) {
|
|
// if astParent is "!" we need to invert codeblock
|
|
const Token *parent = tok->astParent();
|
|
while (parent && parent->str() == "&&")
|
|
parent = parent->astParent();
|
|
if (parent && parent->str() == "!")
|
|
codeblock = (codeblock == 1) ? 2 : 1;
|
|
|
|
// convert codeblock to a startToken
|
|
if (codeblock == 1 && Token::simpleMatch(top->link(), ") {"))
|
|
startToken = top->link()->next();
|
|
else if (Token::simpleMatch(top->link()->linkAt(1), "} else {"))
|
|
startToken = top->link()->linkAt(1)->tokAt(2);
|
|
}
|
|
|
|
bool ok = true;
|
|
if (startToken)
|
|
ok = valueFlowForward(startToken->next(), startToken->link(), var, varid, values, true, tokenlist, errorLogger, settings);
|
|
|
|
// After conditional code..
|
|
if (ok && Token::simpleMatch(top->link(), ") {")) {
|
|
Token *after = top->link()->linkAt(1);
|
|
std::string unknownFunction;
|
|
if (settings->library.isScopeNoReturn(after, &unknownFunction)) {
|
|
if (settings->debugwarnings && !unknownFunction.empty())
|
|
bailout(tokenlist, errorLogger, after, "possible noreturn scope");
|
|
continue;
|
|
}
|
|
|
|
bool isreturn = (codeblock == 1 && isReturn(after));
|
|
|
|
if (Token::simpleMatch(after, "} else {")) {
|
|
after = after->linkAt(2);
|
|
if (Token::simpleMatch(after->tokAt(-2), ") ; }")) {
|
|
if (settings->debugwarnings)
|
|
bailout(tokenlist, errorLogger, after, "possible noreturn scope");
|
|
continue;
|
|
}
|
|
isreturn |= (codeblock == 2 && isReturn(after));
|
|
}
|
|
|
|
if (!isreturn) {
|
|
// TODO: constValue could be true if there are no assignments in the conditional blocks and
|
|
// perhaps if there are no && and no || in the condition
|
|
bool constValue = false;
|
|
valueFlowForward(after->next(), top->scope()->classEnd, var, varid, values, constValue, tokenlist, errorLogger, settings);
|
|
}
|
|
}
|
|
}
|
|
}
|
|
}
|
|
}
|
|
|
|
static void execute(const Token *expr,
|
|
std::map<unsigned int, MathLib::bigint> * const programMemory,
|
|
MathLib::bigint *result,
|
|
bool *error)
|
|
{
|
|
if (!expr)
|
|
*error = true;
|
|
|
|
else if (expr->isNumber()) {
|
|
*result = MathLib::toLongNumber(expr->str());
|
|
if (MathLib::isFloat(expr->str()))
|
|
*error = true;
|
|
}
|
|
|
|
else if (expr->varId() > 0) {
|
|
const std::map<unsigned int, MathLib::bigint>::const_iterator var = programMemory->find(expr->varId());
|
|
if (var == programMemory->end())
|
|
*error = true;
|
|
else
|
|
*result = var->second;
|
|
}
|
|
|
|
else if (expr->isComparisonOp()) {
|
|
MathLib::bigint result1(0), result2(0);
|
|
execute(expr->astOperand1(), programMemory, &result1, error);
|
|
execute(expr->astOperand2(), programMemory, &result2, error);
|
|
if (expr->str() == "<")
|
|
*result = result1 < result2;
|
|
else if (expr->str() == "<=")
|
|
*result = result1 <= result2;
|
|
else if (expr->str() == ">")
|
|
*result = result1 > result2;
|
|
else if (expr->str() == ">=")
|
|
*result = result1 >= result2;
|
|
else if (expr->str() == "==")
|
|
*result = result1 == result2;
|
|
else if (expr->str() == "!=")
|
|
*result = result1 != result2;
|
|
}
|
|
|
|
else if (expr->str() == "=") {
|
|
execute(expr->astOperand2(), programMemory, result, error);
|
|
if (!*error && expr->astOperand1() && expr->astOperand1()->varId())
|
|
(*programMemory)[expr->astOperand1()->varId()] = *result;
|
|
else
|
|
*error = true;
|
|
}
|
|
|
|
else if (Token::Match(expr, "++|--")) {
|
|
if (!expr->astOperand1() || expr->astOperand1()->varId() == 0U)
|
|
*error = true;
|
|
else {
|
|
std::map<unsigned int, MathLib::bigint>::iterator var = programMemory->find(expr->astOperand1()->varId());
|
|
if (var == programMemory->end())
|
|
*error = true;
|
|
else {
|
|
if (var->second == 0 &&
|
|
expr->str() == "--" &&
|
|
expr->astOperand1()->variable() &&
|
|
expr->astOperand1()->variable()->typeStartToken()->isUnsigned())
|
|
*error = true; // overflow
|
|
*result = var->second + (expr->str() == "++" ? 1 : -1);
|
|
var->second = *result;
|
|
}
|
|
}
|
|
}
|
|
|
|
else if (expr->isArithmeticalOp() && expr->astOperand1() && expr->astOperand2()) {
|
|
MathLib::bigint result1(0), result2(0);
|
|
execute(expr->astOperand1(), programMemory, &result1, error);
|
|
execute(expr->astOperand2(), programMemory, &result2, error);
|
|
if (expr->str() == "+")
|
|
*result = result1 + result2;
|
|
else if (expr->str() == "-")
|
|
*result = result1 - result2;
|
|
else if (expr->str() == "*")
|
|
*result = result1 * result2;
|
|
else if (result2 == 0)
|
|
*error = true;
|
|
else if (expr->str() == "/")
|
|
*result = result1 / result2;
|
|
else if (expr->str() == "%")
|
|
*result = result1 % result2;
|
|
}
|
|
|
|
else if (expr->str() == "&&") {
|
|
bool error1 = false;
|
|
execute(expr->astOperand1(), programMemory, result, &error1);
|
|
if (!error1 && *result == 0)
|
|
*result = 0;
|
|
else {
|
|
bool error2 = false;
|
|
execute(expr->astOperand2(), programMemory, result, &error2);
|
|
if (error1 && error2)
|
|
*error = true;
|
|
if (error2)
|
|
*result = 1;
|
|
else
|
|
*result = !!*result;
|
|
}
|
|
}
|
|
|
|
else if (expr->str() == "||") {
|
|
execute(expr->astOperand1(), programMemory, result, error);
|
|
if (*result == 0 && *error == false)
|
|
execute(expr->astOperand2(), programMemory, result, error);
|
|
}
|
|
|
|
else if (expr->str() == "!") {
|
|
execute(expr->astOperand1(), programMemory, result, error);
|
|
*result = !(*result);
|
|
}
|
|
|
|
else if (expr->str() == "," && expr->astOperand1() && expr->astOperand2()) {
|
|
execute(expr->astOperand1(), programMemory, result, error);
|
|
execute(expr->astOperand2(), programMemory, result, error);
|
|
}
|
|
|
|
else if (expr->str() == "[" && expr->astOperand1() && expr->astOperand2()) {
|
|
if (expr->astOperand1()->values.size() != 1U) {
|
|
*error = true;
|
|
return;
|
|
}
|
|
const ValueFlow::Value val = expr->astOperand1()->values.front();
|
|
if (!val.tokvalue || !val.tokvalue->isLiteral()) {
|
|
*error = true;
|
|
return;
|
|
}
|
|
const std::string strValue = val.tokvalue->strValue();
|
|
MathLib::bigint index = 0;
|
|
execute(expr->astOperand2(), programMemory, &index, error);
|
|
if (index >= 0 && index < strValue.size())
|
|
*result = strValue[index];
|
|
else if (index == strValue.size())
|
|
*result = 0;
|
|
else
|
|
*error = true;
|
|
}
|
|
|
|
else
|
|
*error = true;
|
|
}
|
|
|
|
static bool valueFlowForLoop1(const Token *tok, unsigned int * const varid, MathLib::bigint * const num1, MathLib::bigint * const num2, MathLib::bigint * const numAfter)
|
|
{
|
|
tok = tok->tokAt(2);
|
|
if (!Token::Match(tok, "%type%| %var% ="))
|
|
return false;
|
|
const Token * const vartok = Token::Match(tok, "%var% =") ? tok : tok->next();
|
|
*varid = vartok->varId();
|
|
tok = vartok->tokAt(2);
|
|
const Token * const num1tok = Token::Match(tok, "%num% ;") ? tok : nullptr;
|
|
if (num1tok)
|
|
*num1 = MathLib::toLongNumber(num1tok->str());
|
|
while (Token::Match(tok, "%name%|%num%|%or%|+|-|*|/|&|[|]|("))
|
|
tok = (tok->str() == "(") ? tok->link()->next() : tok->next();
|
|
if (!tok || tok->str() != ";")
|
|
return false;
|
|
tok = tok->next();
|
|
const Token *num2tok = nullptr;
|
|
if (Token::Match(tok, "%varid% <|<=|!=", vartok->varId())) {
|
|
tok = tok->next();
|
|
num2tok = tok->astOperand2();
|
|
if (num2tok && num2tok->str() == "(" && !num2tok->astOperand2())
|
|
num2tok = num2tok->astOperand1();
|
|
if (!Token::Match(num2tok, "%num% ;|%oror%")) // TODO: || enlarges the scope of the condition, so it should not cause FP, but it should no lnger be part of this pattern as soon as valueFlowForLoop2 can handle an unknown RHS of || better
|
|
num2tok = 0;
|
|
}
|
|
if (!num2tok)
|
|
return false;
|
|
*num2 = MathLib::toLongNumber(num2tok->str()) - ((tok->str()=="<=") ? 0 : 1);
|
|
*numAfter = *num2 + 1;
|
|
if (!num1tok)
|
|
*num1 = *num2;
|
|
while (tok && tok->str() != ";")
|
|
tok = tok->next();
|
|
if (!Token::Match(tok, "; %varid% ++ ) {", vartok->varId()) && !Token::Match(tok, "; ++ %varid% ) {", vartok->varId()))
|
|
return false;
|
|
return true;
|
|
}
|
|
|
|
static bool valueFlowForLoop2(const Token *tok,
|
|
std::map<unsigned int, MathLib::bigint> *memory1,
|
|
std::map<unsigned int, MathLib::bigint> *memory2,
|
|
std::map<unsigned int, MathLib::bigint> *memoryAfter)
|
|
{
|
|
// for ( firstExpression ; secondExpression ; thirdExpression )
|
|
const Token *firstExpression = tok->next()->astOperand2()->astOperand1();
|
|
const Token *secondExpression = tok->next()->astOperand2()->astOperand2()->astOperand1();
|
|
const Token *thirdExpression = tok->next()->astOperand2()->astOperand2()->astOperand2();
|
|
|
|
std::map<unsigned int, MathLib::bigint> programMemory;
|
|
MathLib::bigint result(0);
|
|
bool error = false;
|
|
execute(firstExpression, &programMemory, &result, &error);
|
|
if (error)
|
|
return false;
|
|
execute(secondExpression, &programMemory, &result, &error);
|
|
if (error) {
|
|
// If a variable is reassigned in second expression, return false
|
|
std::stack<const Token *> tokens;
|
|
tokens.push(secondExpression);
|
|
while (!tokens.empty()) {
|
|
const Token *t = tokens.top();
|
|
tokens.pop();
|
|
if (!t)
|
|
continue;
|
|
if (t->str() == "=" && t->astOperand1() && programMemory.find(t->astOperand1()->varId()) != programMemory.end())
|
|
// TODO: investigate what variable is assigned.
|
|
return false;
|
|
tokens.push(t->astOperand1());
|
|
tokens.push(t->astOperand2());
|
|
}
|
|
}
|
|
|
|
std::map<unsigned int, MathLib::bigint> startMemory(programMemory);
|
|
std::map<unsigned int, MathLib::bigint> endMemory;
|
|
|
|
unsigned int maxcount = 10000;
|
|
while (result != 0 && !error && --maxcount) {
|
|
endMemory = programMemory;
|
|
execute(thirdExpression, &programMemory, &result, &error);
|
|
if (!error)
|
|
execute(secondExpression, &programMemory, &result, &error);
|
|
}
|
|
|
|
memory1->swap(startMemory);
|
|
if (!error) {
|
|
memory2->swap(endMemory);
|
|
memoryAfter->swap(programMemory);
|
|
}
|
|
|
|
return true;
|
|
}
|
|
|
|
static void valueFlowForLoopSimplify(Token * const bodyStart, const unsigned int varid, const MathLib::bigint value, TokenList *tokenlist, ErrorLogger *errorLogger, const Settings *settings)
|
|
{
|
|
const Token * const bodyEnd = bodyStart->link();
|
|
|
|
// Is variable modified inside for loop
|
|
if (isVariableChanged(bodyStart, bodyEnd, varid))
|
|
return;
|
|
|
|
for (Token *tok2 = bodyStart->next(); tok2 != bodyEnd; tok2 = tok2->next()) {
|
|
if (tok2->varId() == varid) {
|
|
const Token * parent = tok2->astParent();
|
|
while (parent) {
|
|
const Token * const p = parent;
|
|
parent = parent->astParent();
|
|
if (!parent || parent->str() == ":")
|
|
break;
|
|
if (parent->str() == "?") {
|
|
if (parent->astOperand2() != p)
|
|
parent = NULL;
|
|
break;
|
|
}
|
|
}
|
|
if (parent) {
|
|
if (settings->debugwarnings)
|
|
bailout(tokenlist, errorLogger, tok2, "For loop variable " + tok2->str() + " stopping on ?");
|
|
continue;
|
|
}
|
|
|
|
ValueFlow::Value value1(value);
|
|
value1.varId = tok2->varId();
|
|
setTokenValue(tok2, value1);
|
|
}
|
|
|
|
if (Token::Match(tok2, "%oror%|&&")) {
|
|
const std::map<unsigned int, MathLib::bigint> programMemory(getProgramMemory(tok2->astTop(), varid, ValueFlow::Value(value)));
|
|
if ((tok2->str() == "&&" && conditionIsFalse(tok2->astOperand1(), programMemory)) ||
|
|
(tok2->str() == "||" && conditionIsTrue(tok2->astOperand1(), programMemory))) {
|
|
// Skip second expression..
|
|
const Token *parent = tok2;
|
|
while (parent && parent->str() == tok2->str())
|
|
parent = parent->astParent();
|
|
// Jump to end of condition
|
|
if (parent && parent->str() == "(") {
|
|
tok2 = parent->link();
|
|
// cast
|
|
if (Token::simpleMatch(tok2, ") ("))
|
|
tok2 = tok2->linkAt(1);
|
|
}
|
|
}
|
|
|
|
}
|
|
if ((tok2->str() == "&&" && conditionIsFalse(tok2->astOperand1(), getProgramMemory(tok2->astTop(), varid, ValueFlow::Value(value)))) ||
|
|
(tok2->str() == "||" && conditionIsTrue(tok2->astOperand1(), getProgramMemory(tok2->astTop(), varid, ValueFlow::Value(value)))))
|
|
break;
|
|
|
|
else if (Token::simpleMatch(tok2, ") {") && Token::findmatch(tok2->link(), "%varid%", tok2, varid)) {
|
|
if (Token::findmatch(tok2, "continue|break|return", tok2->linkAt(1), varid)) {
|
|
if (settings->debugwarnings)
|
|
bailout(tokenlist, errorLogger, tok2, "For loop variable bailout on conditional continue|break|return");
|
|
break;
|
|
}
|
|
if (settings->debugwarnings)
|
|
bailout(tokenlist, errorLogger, tok2, "For loop variable skipping conditional scope");
|
|
tok2 = tok2->next()->link();
|
|
if (Token::simpleMatch(tok2, "} else {")) {
|
|
if (Token::findmatch(tok2, "continue|break|return", tok2->linkAt(2), varid)) {
|
|
if (settings->debugwarnings)
|
|
bailout(tokenlist, errorLogger, tok2, "For loop variable bailout on conditional continue|break|return");
|
|
break;
|
|
}
|
|
|
|
tok2 = tok2->linkAt(2);
|
|
}
|
|
}
|
|
}
|
|
}
|
|
|
|
static void valueFlowForLoopSimplifyAfter(Token *fortok, unsigned int varid, const MathLib::bigint num, TokenList *tokenlist, ErrorLogger *errorLogger, const Settings *settings)
|
|
{
|
|
const Token *vartok = nullptr;
|
|
for (const Token *tok = fortok; tok; tok = tok->next()) {
|
|
if (tok->varId() == varid) {
|
|
vartok = tok;
|
|
break;
|
|
}
|
|
}
|
|
if (!vartok || !vartok->variable())
|
|
return;
|
|
|
|
const Variable *var = vartok->variable();
|
|
const Token *endToken = nullptr;
|
|
if (var->isLocal())
|
|
endToken = var->typeStartToken()->scope()->classEnd;
|
|
else
|
|
endToken = fortok->scope()->classEnd;
|
|
|
|
std::list<ValueFlow::Value> values;
|
|
values.push_back(ValueFlow::Value(num));
|
|
|
|
valueFlowForward(fortok->linkAt(1)->linkAt(1)->next(),
|
|
endToken,
|
|
var,
|
|
varid,
|
|
values,
|
|
false,
|
|
tokenlist,
|
|
errorLogger,
|
|
settings);
|
|
}
|
|
|
|
static void valueFlowForLoop(TokenList *tokenlist, SymbolDatabase* symboldatabase, ErrorLogger *errorLogger, const Settings *settings)
|
|
{
|
|
for (std::list<Scope>::const_iterator scope = symboldatabase->scopeList.begin(); scope != symboldatabase->scopeList.end(); ++scope) {
|
|
if (scope->type != Scope::eFor)
|
|
continue;
|
|
|
|
Token* tok = const_cast<Token*>(scope->classDef);
|
|
Token* const bodyStart = const_cast<Token*>(scope->classStart);
|
|
|
|
if (!Token::simpleMatch(tok->next()->astOperand2(), ";") ||
|
|
!Token::simpleMatch(tok->next()->astOperand2()->astOperand2(), ";"))
|
|
continue;
|
|
|
|
unsigned int varid(0);
|
|
MathLib::bigint num1(0), num2(0), numAfter(0);
|
|
|
|
if (valueFlowForLoop1(tok, &varid, &num1, &num2, &numAfter)) {
|
|
if (num1 <= num2) {
|
|
valueFlowForLoopSimplify(bodyStart, varid, num1, tokenlist, errorLogger, settings);
|
|
valueFlowForLoopSimplify(bodyStart, varid, num2, tokenlist, errorLogger, settings);
|
|
valueFlowForLoopSimplifyAfter(tok, varid, numAfter, tokenlist, errorLogger, settings);
|
|
} else
|
|
valueFlowForLoopSimplifyAfter(tok, varid, num1, tokenlist, errorLogger, settings);
|
|
} else {
|
|
std::map<unsigned int, MathLib::bigint> mem1, mem2, memAfter;
|
|
if (valueFlowForLoop2(tok, &mem1, &mem2, &memAfter)) {
|
|
std::map<unsigned int, MathLib::bigint>::const_iterator it;
|
|
for (it = mem1.begin(); it != mem1.end(); ++it)
|
|
valueFlowForLoopSimplify(bodyStart, it->first, it->second, tokenlist, errorLogger, settings);
|
|
for (it = mem2.begin(); it != mem2.end(); ++it)
|
|
valueFlowForLoopSimplify(bodyStart, it->first, it->second, tokenlist, errorLogger, settings);
|
|
for (it = memAfter.begin(); it != memAfter.end(); ++it)
|
|
valueFlowForLoopSimplifyAfter(tok, it->first, it->second, tokenlist, errorLogger, settings);
|
|
}
|
|
}
|
|
}
|
|
}
|
|
|
|
static void valueFlowInjectParameter(TokenList* tokenlist, ErrorLogger* errorLogger, const Settings* settings, const Variable* arg, const Scope* functionScope, const std::list<ValueFlow::Value>& argvalues)
|
|
{
|
|
// Is argument passed by value or const reference, and is it a known non-class type?
|
|
if (arg->isReference() && !arg->isConst() && !arg->isClass())
|
|
return;
|
|
|
|
// Set value in function scope..
|
|
const unsigned int varid2 = arg->declarationId();
|
|
if (!varid2)
|
|
return;
|
|
|
|
valueFlowForward(const_cast<Token*>(functionScope->classStart->next()), functionScope->classEnd, arg, varid2, argvalues, true, tokenlist, errorLogger, settings);
|
|
}
|
|
|
|
static void valueFlowSwitchVariable(TokenList *tokenlist, SymbolDatabase* symboldatabase, ErrorLogger *errorLogger, const Settings *settings)
|
|
{
|
|
for (std::list<Scope>::iterator scope = symboldatabase->scopeList.begin(); scope != symboldatabase->scopeList.end(); ++scope) {
|
|
if (scope->type != Scope::ScopeType::eSwitch)
|
|
continue;
|
|
if (!Token::Match(scope->classDef, "switch ( %var% ) {"))
|
|
continue;
|
|
const Token *vartok = scope->classDef->tokAt(2);
|
|
if (!vartok->variable())
|
|
continue;
|
|
|
|
// bailout: global non-const variables
|
|
const Variable *var = vartok->variable();
|
|
if (!(var->isLocal() || var->isArgument()) && !var->isConst()) {
|
|
if (settings->debugwarnings)
|
|
bailout(tokenlist, errorLogger, vartok, "switch variable " + var->name() + " is global");
|
|
continue;
|
|
}
|
|
|
|
for (Token *tok = scope->classStart->next(); tok != scope->classEnd; tok = tok->next()) {
|
|
if (tok->str() == "{") {
|
|
tok = tok->link();
|
|
continue;
|
|
}
|
|
if (Token::Match(tok, "case %num% :")) {
|
|
std::list<ValueFlow::Value> values;
|
|
values.push_back(ValueFlow::Value(MathLib::toLongNumber(tok->next()->str())));
|
|
while (Token::Match(tok->tokAt(3), "case %num% :")) {
|
|
tok = tok->tokAt(3);
|
|
values.push_back(ValueFlow::Value(MathLib::toLongNumber(tok->next()->str())));
|
|
}
|
|
for (std::list<ValueFlow::Value>::const_iterator val = values.begin(); val != values.end(); ++val) {
|
|
valueFlowReverse(tokenlist,
|
|
const_cast<Token*>(scope->classDef),
|
|
vartok,
|
|
*val,
|
|
ValueFlow::Value(),
|
|
errorLogger,
|
|
settings);
|
|
}
|
|
valueFlowForward(tok, vartok->variable()->scope()->classEnd, vartok->variable(), vartok->varId(), values, false, tokenlist, errorLogger, settings);
|
|
}
|
|
}
|
|
}
|
|
}
|
|
|
|
static void valueFlowSubFunction(TokenList *tokenlist, ErrorLogger *errorLogger, const Settings *settings)
|
|
{
|
|
for (Token *tok = tokenlist->front(); tok; tok = tok->next()) {
|
|
if (!Token::Match(tok, "%name% ("))
|
|
continue;
|
|
|
|
const Function * const currentFunction = tok->function();
|
|
if (!currentFunction)
|
|
continue;
|
|
|
|
// Function scope..
|
|
const Scope * const functionScope = currentFunction->functionScope;
|
|
if (!functionScope)
|
|
continue;
|
|
|
|
unsigned int argnr = 0U;
|
|
for (const Token *argtok = tok->tokAt(2); argtok; argtok = argtok->nextArgument()) {
|
|
// Get function argument
|
|
const Variable * const arg = currentFunction->getArgumentVar(argnr++);
|
|
if (!arg)
|
|
break;
|
|
|
|
std::list<ValueFlow::Value> argvalues;
|
|
|
|
// passing value(s) to function
|
|
if (!argtok->values.empty() && Token::Match(argtok, "%name%|%num%|%str% [,)]"))
|
|
argvalues = argtok->values;
|
|
else {
|
|
// bool operator => values 1/0 are passed to function..
|
|
const Token *op = argtok;
|
|
while (op && op->astParent() && !Token::Match(op->astParent(), "[(,]"))
|
|
op = op->astParent();
|
|
if (Token::Match(op, "%comp%|%oror%|&&|!")) {
|
|
argvalues.clear();
|
|
argvalues.push_back(ValueFlow::Value(0));
|
|
argvalues.push_back(ValueFlow::Value(1));
|
|
} else if (Token::Match(op, "%cop%") && !op->values.empty()) {
|
|
argvalues = op->values;
|
|
} else {
|
|
// possible values are unknown..
|
|
continue;
|
|
}
|
|
}
|
|
|
|
// passed values are not "known"..
|
|
for (std::list<ValueFlow::Value>::iterator it = argvalues.begin(); it != argvalues.end(); ++it) {
|
|
if (it->valueKind == ValueFlow::Value::Known)
|
|
it->valueKind = ValueFlow::Value::Possible;
|
|
}
|
|
|
|
valueFlowInjectParameter(tokenlist, errorLogger, settings, arg, functionScope, argvalues);
|
|
}
|
|
}
|
|
}
|
|
|
|
static void valueFlowFunctionDefaultParameter(TokenList *tokenlist, SymbolDatabase* symboldatabase, ErrorLogger *errorLogger, const Settings *settings)
|
|
{
|
|
if (!tokenlist->isCPP())
|
|
return;
|
|
|
|
const std::size_t functions = symboldatabase->functionScopes.size();
|
|
for (std::size_t i = 0; i < functions; ++i) {
|
|
const Scope* scope = symboldatabase->functionScopes[i];
|
|
const Function* function = scope->function;
|
|
if (!function)
|
|
continue;
|
|
for (std::size_t arg = function->minArgCount(); arg < function->argCount(); arg++) {
|
|
const Variable* var = function->getArgumentVar(arg);
|
|
if (var && var->hasDefault() && Token::Match(var->nameToken(), "%var% = %num%|%str% [,)]")) {
|
|
const std::list<ValueFlow::Value> &values = var->nameToken()->tokAt(2)->values;
|
|
std::list<ValueFlow::Value> argvalues;
|
|
for (std::list<ValueFlow::Value>::const_iterator it = values.begin(); it != values.end(); ++it) {
|
|
ValueFlow::Value v(*it);
|
|
v.defaultArg = true;
|
|
if (v.valueKind == ValueFlow::Value::Known)
|
|
v.valueKind = ValueFlow::Value::Possible;
|
|
if (v.valueKind == ValueFlow::Value::Possible)
|
|
argvalues.push_back(v);
|
|
}
|
|
if (!argvalues.empty())
|
|
valueFlowInjectParameter(tokenlist, errorLogger, settings, var, scope, argvalues);
|
|
}
|
|
}
|
|
}
|
|
}
|
|
|
|
static bool constval(const Token * tok)
|
|
{
|
|
return tok && tok->values.size() == 1U && tok->values.front().varId == 0U;
|
|
}
|
|
|
|
static void valueFlowFunctionReturn(TokenList *tokenlist, ErrorLogger *errorLogger, const Settings *settings)
|
|
{
|
|
for (Token *tok = tokenlist->front(); tok; tok = tok->next()) {
|
|
if (tok->str() != "(" || !tok->astOperand1() || !tok->astOperand1()->function())
|
|
continue;
|
|
|
|
// Arguments..
|
|
std::vector<MathLib::bigint> parvalues;
|
|
{
|
|
const Token *partok = tok->astOperand2();
|
|
while (partok && partok->str() == "," && constval(partok->astOperand2()))
|
|
partok = partok->astOperand1();
|
|
if (!constval(partok))
|
|
continue;
|
|
parvalues.push_back(partok->values.front().intvalue);
|
|
partok = partok->astParent();
|
|
while (partok && partok->str() == ",") {
|
|
parvalues.push_back(partok->astOperand2()->values.front().intvalue);
|
|
partok = partok->astParent();
|
|
}
|
|
if (partok != tok)
|
|
continue;
|
|
}
|
|
|
|
// Get scope and args of function
|
|
const Function * const function = tok->astOperand1()->function();
|
|
const Scope * const functionScope = function->functionScope;
|
|
if (!functionScope || !Token::simpleMatch(functionScope->classStart, "{ return")) {
|
|
if (functionScope && settings->debugwarnings)
|
|
bailout(tokenlist, errorLogger, tok, "function return; nontrivial function body");
|
|
continue;
|
|
}
|
|
|
|
std::map<unsigned int, MathLib::bigint> programMemory;
|
|
for (std::size_t i = 0; i < parvalues.size(); ++i) {
|
|
const Variable * const arg = function->getArgumentVar(i);
|
|
if (!arg || !Token::Match(arg->typeStartToken(), "%type% %name% ,|)")) {
|
|
if (settings->debugwarnings)
|
|
bailout(tokenlist, errorLogger, tok, "function return; unhandled argument type");
|
|
programMemory.clear();
|
|
break;
|
|
}
|
|
programMemory[arg->declarationId()] = parvalues[i];
|
|
}
|
|
if (programMemory.empty())
|
|
continue;
|
|
|
|
// Determine return value of subfunction..
|
|
MathLib::bigint result = 0;
|
|
bool error = false;
|
|
execute(functionScope->classStart->next()->astOperand1(),
|
|
&programMemory,
|
|
&result,
|
|
&error);
|
|
if (!error)
|
|
setTokenValue(tok, ValueFlow::Value(result));
|
|
}
|
|
}
|
|
|
|
void ValueFlow::setValues(TokenList *tokenlist, SymbolDatabase* symboldatabase, ErrorLogger *errorLogger, const Settings *settings)
|
|
{
|
|
for (Token *tok = tokenlist->front(); tok; tok = tok->next())
|
|
tok->values.clear();
|
|
|
|
valueFlowNumber(tokenlist);
|
|
valueFlowString(tokenlist);
|
|
valueFlowArray(tokenlist);
|
|
valueFlowPointerAlias(tokenlist);
|
|
valueFlowFunctionReturn(tokenlist, errorLogger, settings);
|
|
valueFlowBitAnd(tokenlist);
|
|
valueFlowForLoop(tokenlist, symboldatabase, errorLogger, settings);
|
|
valueFlowBeforeCondition(tokenlist, symboldatabase, errorLogger, settings);
|
|
valueFlowAfterAssign(tokenlist, symboldatabase, errorLogger, settings);
|
|
valueFlowAfterCondition(tokenlist, symboldatabase, errorLogger, settings);
|
|
valueFlowSwitchVariable(tokenlist, symboldatabase, errorLogger, settings);
|
|
valueFlowSubFunction(tokenlist, errorLogger, settings);
|
|
valueFlowFunctionDefaultParameter(tokenlist, symboldatabase, errorLogger, settings);
|
|
}
|