1470 lines
59 KiB
C++
1470 lines
59 KiB
C++
/*
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* Cppcheck - A tool for static C/C++ code analysis
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* Copyright (C) 2007-2014 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), ") & %var% [,)]") && Token::Match(tok->linkAt(-2)->previous(), "[,(] ("))
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;
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else if (Token::Match(tok->tokAt(addressOf?-2:-1), "[(,] &| %var% [,)]"))
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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), "> ( & %var% ) [,)]") &&
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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,"%var% ("))
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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->str(), 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 varid variable id for variable
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* \param value value of variable
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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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bool result1 = conditionIsFalse(condition->astOperand1(), programMemory);
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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 varid variable id for variable
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* \param value value of variable
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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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bool result1 = conditionIsTrue(condition->astOperand1(), programMemory);
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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;
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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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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, "[;{}] %var% = %num% ;")) {
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const Token *vartok = tok2->next();
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const Token *numtok = tok2->tokAt(3);
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if (vartok->varId() != 0U && programMemory.find(vartok->varId()) == programMemory.end())
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programMemory[vartok->varId()] = MathLib::toLongNumber(numtok->str());
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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 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, "%var% ="))
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return true;
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const Token *parent = tok->astParent();
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while (parent && parent->str() == ".")
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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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/** 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 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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break;
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}
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// Same value already exists, don't add new value
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return;
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}
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if (it == tok->values.end()) {
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tok->values.push_back(value);
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it = tok->values.end();
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--it;
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if (it->varId == 0)
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it->varId = tok->varId();
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}
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Token *parent = const_cast<Token*>(tok->astParent());
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// Cast..
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if (parent && parent->str() == "(" && tok == parent->link()->next()) {
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setTokenValue(parent,value);
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}
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// Calculations..
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else if (parent && parent->isArithmeticalOp() && 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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for (value2 = parent->astOperand2()->values.begin(); value2 != parent->astOperand2()->values.end(); ++value2) {
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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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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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static void valueFlowNumber(TokenList *tokenlist)
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{
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for (Token *tok = tokenlist->front(); tok; tok = tok->next()) {
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if (tok->isNumber() && MathLib::isInt(tok->str()))
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setTokenValue(tok, ValueFlow::Value(MathLib::toLongNumber(tok->str())));
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}
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}
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static void valueFlowString(TokenList *tokenlist)
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{
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for (Token *tok = tokenlist->front(); tok; tok = tok->next()) {
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if (tok->type() == Token::eString) {
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ValueFlow::Value strvalue;
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strvalue.tokvalue = tok;
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setTokenValue(tok, strvalue);
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}
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}
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}
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static void valueFlowPointerAlias(TokenList *tokenlist)
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{
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for (Token *tok = tokenlist->front(); tok; tok = tok->next()) {
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// not address of
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if (tok->str() != "&" || tok->astOperand2())
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continue;
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// parent should be a '='
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if (!Token::simpleMatch(tok->astParent(), "="))
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continue;
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// child should be some buffer or variable
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if (!Token::Match(tok->astOperand1(), "%var%|.|["))
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continue;
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ValueFlow::Value value;
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value.tokvalue = tok;
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setTokenValue(tok, value);
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}
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}
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static void valueFlowBitAnd(TokenList *tokenlist)
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{
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for (Token *tok = tokenlist->front(); tok; tok = tok->next()) {
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if (tok->str() != "&")
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continue;
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if (!tok->astOperand1() || !tok->astOperand2())
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continue;
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MathLib::bigint number;
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if (MathLib::isInt(tok->astOperand1()->str()))
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number = MathLib::toLongNumber(tok->astOperand1()->str());
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else if (MathLib::isInt(tok->astOperand2()->str()))
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number = MathLib::toLongNumber(tok->astOperand2()->str());
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else
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continue;
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int bit = 0;
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while (bit <= 60 && ((1LL<<bit) < number))
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++bit;
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if ((1LL<<bit) == number) {
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setTokenValue(tok, ValueFlow::Value(0));
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setTokenValue(tok, ValueFlow::Value(number));
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}
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}
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}
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static void valueFlowBeforeCondition(TokenList *tokenlist, ErrorLogger *errorLogger, const Settings *settings)
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{
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for (Token *tok = tokenlist->front(); tok; tok = tok->next()) {
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unsigned int varid=0;
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MathLib::bigint num=0;
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const Variable *var=0;
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if (tok->isComparisonOp() && tok->astOperand1() && tok->astOperand2()) {
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if (tok->astOperand1()->isName() && tok->astOperand2()->isNumber()) {
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varid = tok->astOperand1()->varId();
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var = tok->astOperand1()->variable();
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num = MathLib::toLongNumber(tok->astOperand2()->str());
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} else if (tok->astOperand1()->isNumber() && tok->astOperand2()->isName()) {
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varid = tok->astOperand2()->varId();
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var = tok->astOperand2()->variable();
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num = MathLib::toLongNumber(tok->astOperand1()->str());
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} else {
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continue;
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}
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} else if (Token::Match(tok->previous(), "if|while ( %var% %oror%|&&|)") ||
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Token::Match(tok, "%oror%|&& %var% %oror%|&&|)")) {
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varid = tok->next()->varId();
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var = tok->next()->variable();
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num = 0;
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} else if (tok->str() == "!" && tok->astOperand1() && tok->astOperand1()->isName()) {
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varid = tok->astOperand1()->varId();
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var = tok->astOperand1()->variable();
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num = 0;
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} else {
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continue;
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}
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if (varid == 0U || !var)
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continue;
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// bailout: global non-const variables
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if (!(var->isLocal() || var->isArgument()) && !var->isConst()) {
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if (settings->debugwarnings)
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bailout(tokenlist, errorLogger, tok, "global variable " + var->nameToken()->str());
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continue;
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}
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// bailout: for/while-condition, variable is changed in while loop
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for (const Token *tok2 = tok; tok2; tok2 = tok2->astParent()) {
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if (tok2->astParent() || tok2->str() != "(" || !Token::simpleMatch(tok2->link(), ") {"))
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continue;
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if (Token::Match(tok2->previous(), "for|while (")) {
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const Token * const start = tok2->link()->next();
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const Token * const end = start->link();
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if (isVariableChanged(start,end,varid)) {
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varid = 0U;
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if (settings->debugwarnings)
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bailout(tokenlist, errorLogger, tok, "variable " + var->nameToken()->str() + " used in loop");
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}
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}
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// if,macro => bailout
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else if (Token::simpleMatch(tok2->previous(), "if (") && tok2->previous()->isExpandedMacro()) {
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varid = 0U;
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if (settings->debugwarnings)
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bailout(tokenlist, errorLogger, tok, "variable " + var->nameToken()->str() + ", condition is defined in macro");
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}
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}
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if (varid == 0U)
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continue;
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// extra logic for unsigned variables 'i>=1' => possible value can also be 0
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ValueFlow::Value val(tok, num);
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val.varId = varid;
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ValueFlow::Value val2;
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if (num==1U && Token::Match(tok,"<=|>=")) {
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bool isunsigned = false;
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for (const Token* type = var->typeStartToken(); type && type->varId() == 0U; type = type->next())
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isunsigned |= type->isUnsigned();
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if (isunsigned) {
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val2 = ValueFlow::Value(tok,0);
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val2.varId = varid;
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}
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}
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if (Token::Match(tok,"<|>")) {
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if (num!=0)
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continue;
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bool isunsigned = false;
|
|
for (const Token* type = var->typeStartToken(); type && type->varId() == 0U; type = type->next())
|
|
isunsigned |= type->isUnsigned();
|
|
if (!isunsigned)
|
|
continue;
|
|
}
|
|
for (Token *tok2 = tok->previous(); ; tok2 = tok2->previous()) {
|
|
if (!tok2) {
|
|
if (settings->debugwarnings) {
|
|
std::list<ErrorLogger::ErrorMessage::FileLocation> callstack;
|
|
callstack.push_back(ErrorLogger::ErrorMessage::FileLocation(tok,tokenlist));
|
|
ErrorLogger::ErrorMessage errmsg(callstack, Severity::debug, "iterated too far", "debugValueFlowBeforeCondition", false);
|
|
errorLogger->reportErr(errmsg);
|
|
}
|
|
break;
|
|
}
|
|
|
|
if (tok2->varId() == varid) {
|
|
// bailout: assignment
|
|
if (Token::Match(tok2->previous(), "!!* %var% =")) {
|
|
if (settings->debugwarnings)
|
|
bailout(tokenlist, errorLogger, tok2, "assignment of " + tok2->str());
|
|
break;
|
|
}
|
|
|
|
// increment/decrement
|
|
if (Token::Match(tok2->previous(), "[;{}] %var% ++|-- ;"))
|
|
val.intvalue += (tok2->strAt(1)=="++") ? -1 : 1;
|
|
else if (Token::Match(tok2->tokAt(-2), "[;{}] ++|-- %var% ;"))
|
|
val.intvalue += (tok2->strAt(-1)=="++") ? -1 : 1;
|
|
else if (Token::Match(tok2->previous(), "++|-- %var%") || Token::Match(tok2, "%var% ++|--")) {
|
|
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,"%var%|.") && 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, "[;{}] %var% :")) {
|
|
if (settings->debugwarnings)
|
|
bailout(tokenlist, errorLogger, tok2->next(), "variable " + var->nameToken()->str() + " stopping on goto label");
|
|
break;
|
|
}
|
|
|
|
if (tok2->str() == "}") {
|
|
const Token *vartok = Token::findmatch(tok2->link(), "%varid%", tok2, varid);
|
|
while (Token::Match(vartok, "%var% = %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->nameToken()->str() + " ";
|
|
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->nameToken()->str() + " 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->nameToken()->str() + " stopping on " + parent->str());
|
|
break;
|
|
}
|
|
}
|
|
}
|
|
}
|
|
}
|
|
|
|
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 ";"
|
|
|
|
for (Token *tok2 = startToken; tok2 && tok2 != endToken; tok2 = tok2->next()) {
|
|
if (indentlevel >= 0 && tok2->str() == "{")
|
|
++indentlevel;
|
|
else if (indentlevel >= 0 && tok2->str() == "}")
|
|
--indentlevel;
|
|
|
|
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;
|
|
}
|
|
}
|
|
|
|
// conditional block of code that assigns variable..
|
|
else if (Token::Match(tok2, "%var% (") && Token::simpleMatch(tok2->linkAt(1), ") {")) {
|
|
// Should scope be skipped because variable value is checked?
|
|
bool skip = false;
|
|
for (std::list<ValueFlow::Value>::iterator it = values.begin(); it != values.end(); ++it) {
|
|
if (conditionIsFalse(tok2->next()->astOperand2(), getProgramMemory(tok2, varid, *it))) {
|
|
skip = true;
|
|
break;
|
|
}
|
|
}
|
|
if (skip) {
|
|
// goto '{'
|
|
tok2 = tok2->linkAt(1)->next();
|
|
// goto '}'
|
|
tok2 = tok2->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 (varusage) {
|
|
varusagelevel = indentlevel;
|
|
|
|
if (indentlevel < 0 && tok2->str() == "switch")
|
|
return false;
|
|
|
|
// TODO: don't check noreturn scopes
|
|
if (number_of_if > 0U || Token::findmatch(tok2, "%varid%", start, varid)) {
|
|
if (settings->debugwarnings)
|
|
bailout(tokenlist, errorLogger, tok2, "variable " + var->nameToken()->str() + " is assigned in conditional code");
|
|
return false;
|
|
}
|
|
|
|
if (var->isStatic()) {
|
|
if (settings->debugwarnings)
|
|
bailout(tokenlist, errorLogger, tok2, "variable " + var->nameToken()->str() + " 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
|
|
++it;
|
|
}
|
|
}
|
|
|
|
// 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->nameToken()->str() + ". noreturn conditional scope.");
|
|
return false;
|
|
}
|
|
|
|
if (isVariableChanged(start, end, varid)) {
|
|
if (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 {
|
|
if (settings->debugwarnings)
|
|
bailout(tokenlist, errorLogger, tok2, "variable " + var->nameToken()->str() + " 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 (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;
|
|
continue;
|
|
}
|
|
}
|
|
if (settings->debugwarnings)
|
|
bailout(tokenlist, errorLogger, tok2, "variable " + var->nameToken()->str() + ". noreturn conditional scope.");
|
|
return false;
|
|
}
|
|
|
|
else if (indentlevel <= 0 && Token::Match(tok2, "return|throw"))
|
|
returnStatement = true;
|
|
|
|
else if (returnStatement && tok2->str() == ";")
|
|
return false;
|
|
|
|
if (tok2->varId() == varid) {
|
|
// bailout: assignment
|
|
if (Token::Match(tok2->previous(), "!!* %var% %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(tok2, *it);
|
|
} else if (Token::Match(tok3, "++|--|?|:|;"))
|
|
break;
|
|
}
|
|
if (settings->debugwarnings)
|
|
bailout(tokenlist, errorLogger, tok2, "assignment of " + tok2->str());
|
|
return false;
|
|
}
|
|
|
|
// bailout increment/decrement for now..
|
|
if (Token::Match(tok2->previous(), "++|-- %var%") || Token::Match(tok2, "%var% ++|--")) {
|
|
if (settings->debugwarnings)
|
|
bailout(tokenlist, errorLogger, tok2, "increment/decrement of " + tok2->str());
|
|
return false;
|
|
}
|
|
|
|
// bailout: possible assignment using >>
|
|
if (Token::Match(tok2->previous(), ">> %var% >>|;")) {
|
|
const Token *parent = tok2->previous();
|
|
while (Token::simpleMatch(parent,">>"))
|
|
parent = parent->astParent();
|
|
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");
|
|
continue;
|
|
}
|
|
|
|
{
|
|
std::list<ValueFlow::Value>::const_iterator it;
|
|
for (it = values.begin(); it != values.end(); ++it)
|
|
setTokenValue(tok2, *it);
|
|
}
|
|
|
|
// 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, ErrorLogger *errorLogger, const Settings *settings)
|
|
{
|
|
for (Token *tok = tokenlist->front(); tok; tok = tok->next()) {
|
|
// Assignment
|
|
if ((tok->str() != "=") || (tok->astParent()))
|
|
continue;
|
|
|
|
// Lhs should be a variable
|
|
if (!tok->astOperand1() || !tok->astOperand1()->isName())
|
|
continue;
|
|
const unsigned int varid = tok->astOperand1()->varId();
|
|
if (varid == 0U)
|
|
continue;
|
|
const Variable *var = tok->astOperand1()->variable();
|
|
if (!var || !var->isLocal())
|
|
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();
|
|
valueFlowForward(tok, endOfVarScope, var, varid, values, constValue, tokenlist, errorLogger, settings);
|
|
}
|
|
}
|
|
|
|
static void valueFlowAfterCondition(TokenList *tokenlist, ErrorLogger *errorLogger, const Settings *settings)
|
|
{
|
|
for (Token *tok = tokenlist->front(); tok; tok = tok->next()) {
|
|
const Token *vartok, *numtok;
|
|
|
|
// Comparison
|
|
if (Token::Match(tok,"==|!=|>=|<=")) {
|
|
if (!tok->astOperand1() || !tok->astOperand2())
|
|
continue;
|
|
if (tok->astOperand1()->isName()) {
|
|
vartok = tok->astOperand1();
|
|
numtok = tok->astOperand2();
|
|
} else {
|
|
vartok = tok->astOperand2();
|
|
numtok = tok->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, "%var%|!=")))) {
|
|
bool assign = false;
|
|
for (; !assign && parent && parent->str() == op; parent = const_cast<Token*>(parent->astParent())) {
|
|
std::stack<Token *> tokens;
|
|
tokens.push(const_cast<Token*>(parent->astOperand2()));
|
|
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;
|
|
}
|
|
}
|
|
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 (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, "%var%|!="))
|
|
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;
|
|
}
|
|
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;
|
|
}
|
|
}
|
|
valueFlowForward(after->next(), top->scope()->classEnd, var, varid, values, true, 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 (expr->str() == "++" || expr->str() == "--") {
|
|
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
|
|
*error = true;
|
|
}
|
|
|
|
static bool valueFlowForLoop1(const Token *tok, unsigned int * const varid, MathLib::bigint * const num1, MathLib::bigint * const num2)
|
|
{
|
|
tok = tok->tokAt(2);
|
|
if (!Token::Match(tok,"%type%| %var% ="))
|
|
return false;
|
|
const Token * const vartok = tok->tokAt(Token::Match(tok, "%var% =") ? 0 : 1);
|
|
if (vartok->varId() == 0U)
|
|
return false;
|
|
*varid = vartok->varId();
|
|
const Token * const num1tok = Token::Match(vartok->tokAt(2), "%num% ;") ? vartok->tokAt(2) : nullptr;
|
|
if (num1tok)
|
|
*num1 = MathLib::toLongNumber(num1tok->str());
|
|
tok = vartok->tokAt(2);
|
|
while (Token::Match(tok, "%var%|%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%"))
|
|
num2tok = 0;
|
|
}
|
|
if (!num2tok)
|
|
return false;
|
|
*num2 = MathLib::toLongNumber(num2tok->str()) - ((tok->str()=="<=") ? 0 : 1);
|
|
if (!num1tok)
|
|
*num1 = *num2;
|
|
while (tok && tok->str() != ";")
|
|
tok = tok->next();
|
|
if (!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)
|
|
{
|
|
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() == "=" && 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);
|
|
|
|
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 && 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, 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();
|
|
if (parent && parent->str() == "(")
|
|
tok2 = parent->link();
|
|
}
|
|
|
|
}
|
|
if ((tok2->str() == "&&" && conditionIsFalse(tok2->astOperand1(), getProgramMemory(tok2->astTop(), varid, value))) ||
|
|
(tok2->str() == "||" && conditionIsTrue(tok2->astOperand1(), getProgramMemory(tok2->astTop(), varid, 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 valueFlowForLoop(TokenList *tokenlist, ErrorLogger *errorLogger, const Settings *settings)
|
|
{
|
|
for (Token *tok = tokenlist->front(); tok; tok = tok->next()) {
|
|
if (!Token::simpleMatch(tok, "for (") ||
|
|
!Token::simpleMatch(tok->next()->astOperand2(), ";") ||
|
|
!Token::simpleMatch(tok->next()->astOperand2()->astOperand2(), ";"))
|
|
continue;
|
|
|
|
Token * const bodyStart = tok->linkAt(1)->next();
|
|
|
|
unsigned int varid(0);
|
|
MathLib::bigint num1(0), num2(0);
|
|
|
|
if (valueFlowForLoop1(tok, &varid, &num1, &num2)) {
|
|
valueFlowForLoopSimplify(bodyStart, varid, num1, tokenlist, errorLogger, settings);
|
|
valueFlowForLoopSimplify(bodyStart, varid, num2, tokenlist, errorLogger, settings);
|
|
} else {
|
|
std::map<unsigned int, MathLib::bigint> mem1, mem2;
|
|
if (valueFlowForLoop2(tok, &mem1, &mem2)) {
|
|
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);
|
|
}
|
|
}
|
|
}
|
|
}
|
|
|
|
static void valueFlowSubFunction(TokenList *tokenlist, ErrorLogger *errorLogger, const Settings *settings)
|
|
{
|
|
std::list<ValueFlow::Value> argvalues;
|
|
for (Token *tok = tokenlist->front(); tok; tok = tok->next()) {
|
|
if (!Token::Match(tok, "[(,]"))
|
|
continue;
|
|
|
|
// passing value(s) to function
|
|
if (Token::Match(tok, "[(,] %var% [,)]") && !tok->next()->values.empty())
|
|
argvalues = tok->next()->values;
|
|
else if (Token::Match(tok, "[(,] %num% [,)]") && MathLib::isInt(tok->strAt(1))) {
|
|
argvalues.clear();
|
|
argvalues.push_back(ValueFlow::Value(MathLib::toLongNumber(tok->next()->str())));
|
|
} else {
|
|
// bool operator => values 1/0 are passed to function..
|
|
const Token *op = tok->next();
|
|
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 {
|
|
// possible values are unknown..
|
|
continue;
|
|
}
|
|
}
|
|
|
|
const Token * const argumentToken = tok->next();
|
|
|
|
// is this a function call?
|
|
const Token *ftok = tok;
|
|
while (ftok && ftok->str() != "(")
|
|
ftok = ftok->astParent();
|
|
if (!ftok || !ftok->astOperand1() || !ftok->astOperand2() || !ftok->astOperand1()->function())
|
|
continue;
|
|
|
|
// Get argument nr
|
|
unsigned int argnr = 0;
|
|
for (const Token *argtok = ftok->next(); argtok && argtok != argumentToken; argtok = argtok->nextArgument())
|
|
++ argnr;
|
|
|
|
// Get function argument, and check if parameter is passed by value
|
|
const Function * const function = ftok->astOperand1()->function();
|
|
const Variable * const arg = function ? function->getArgumentVar(argnr) : nullptr;
|
|
if (!Token::Match(arg ? arg->typeStartToken() : nullptr, "%type% %var% ,|)"))
|
|
continue;
|
|
|
|
// Function scope..
|
|
const Scope * const functionScope = function ? function->functionScope : nullptr;
|
|
if (!functionScope)
|
|
continue;
|
|
|
|
// Set value in function scope..
|
|
const unsigned int varid2 = arg->nameToken()->varId();
|
|
for (const Token *tok2 = functionScope->classStart->next(); tok2 != functionScope->classEnd; tok2 = tok2->next()) {
|
|
if (Token::Match(tok2, "%varid% !!=", varid2)) {
|
|
for (std::list<ValueFlow::Value>::const_iterator val = argvalues.begin(); val != argvalues.end(); ++val)
|
|
setTokenValue(const_cast<Token*>(tok2), *val);
|
|
} else if (tok2->str() == "{" || tok2->str() == "?") {
|
|
if (settings->debugwarnings)
|
|
bailout(tokenlist, errorLogger, tok2, "parameter " + arg->nameToken()->str() + ", at '" + tok2->str() + "'");
|
|
break;
|
|
}
|
|
}
|
|
}
|
|
}
|
|
|
|
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 ? function->functionScope : nullptr;
|
|
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% %var% ,|)")) {
|
|
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, ErrorLogger *errorLogger, const Settings *settings)
|
|
{
|
|
for (Token *tok = tokenlist->front(); tok; tok = tok->next())
|
|
tok->values.clear();
|
|
|
|
valueFlowNumber(tokenlist);
|
|
valueFlowString(tokenlist);
|
|
valueFlowPointerAlias(tokenlist);
|
|
valueFlowFunctionReturn(tokenlist, errorLogger, settings);
|
|
valueFlowBitAnd(tokenlist);
|
|
valueFlowForLoop(tokenlist, errorLogger, settings);
|
|
valueFlowBeforeCondition(tokenlist, errorLogger, settings);
|
|
valueFlowAfterAssign(tokenlist, errorLogger, settings);
|
|
valueFlowAfterCondition(tokenlist, errorLogger, settings);
|
|
valueFlowSubFunction(tokenlist, errorLogger, settings);
|
|
}
|