604 lines
21 KiB
C++
604 lines
21 KiB
C++
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#include "programmemory.h"
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#include "astutils.h"
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#include "mathlib.h"
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#include "symboldatabase.h"
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#include "token.h"
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#include "valueflow.h"
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#include <algorithm>
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#include <cassert>
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#include <limits>
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#include <memory>
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void ProgramMemory::setValue(nonneg int exprid, const ValueFlow::Value& value)
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{
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values[exprid] = value;
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}
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const ValueFlow::Value* ProgramMemory::getValue(nonneg int exprid, bool impossible) const
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{
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const ProgramMemory::Map::const_iterator it = values.find(exprid);
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const bool found = it != values.end() && (impossible || !it->second.isImpossible());
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if (found)
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return &it->second;
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else
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return nullptr;
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}
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bool ProgramMemory::getIntValue(nonneg int exprid, MathLib::bigint* result) const
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{
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const ValueFlow::Value* value = getValue(exprid);
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if (value && value->isIntValue()) {
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*result = value->intvalue;
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return true;
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}
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return false;
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}
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void ProgramMemory::setIntValue(nonneg int exprid, MathLib::bigint value)
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{
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values[exprid] = ValueFlow::Value(value);
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}
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bool ProgramMemory::getTokValue(nonneg int exprid, const Token** result) const
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{
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const ValueFlow::Value* value = getValue(exprid);
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if (value && value->isTokValue()) {
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*result = value->tokvalue;
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return true;
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}
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return false;
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}
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bool ProgramMemory::getContainerSizeValue(nonneg int exprid, MathLib::bigint* result) const
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{
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const ValueFlow::Value* value = getValue(exprid);
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if (value && value->isContainerSizeValue()) {
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*result = value->intvalue;
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return true;
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}
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return false;
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}
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bool ProgramMemory::getContainerEmptyValue(nonneg int exprid, MathLib::bigint* result) const
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{
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const ValueFlow::Value* value = getValue(exprid, true);
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if (value && value->isContainerSizeValue()) {
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if (value->isImpossible() && value->intvalue == 0) {
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*result = false;
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return true;
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}
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if (!value->isImpossible()) {
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*result = (value->intvalue == 0);
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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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void ProgramMemory::setUnknown(nonneg int exprid)
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{
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values[exprid].valueType = ValueFlow::Value::ValueType::UNINIT;
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}
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bool ProgramMemory::hasValue(nonneg int exprid)
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{
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return values.find(exprid) != values.end();
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}
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void ProgramMemory::swap(ProgramMemory &pm)
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{
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values.swap(pm.values);
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}
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void ProgramMemory::clear()
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{
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values.clear();
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}
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bool ProgramMemory::empty() const
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{
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return values.empty();
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}
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void ProgramMemory::replace(const ProgramMemory &pm)
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{
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for (auto&& p : pm.values) {
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values[p.first] = p.second;
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}
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}
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void ProgramMemory::insert(const ProgramMemory &pm)
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{
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for (auto&& p:pm.values)
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values.insert(p);
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}
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bool conditionIsFalse(const Token *condition, const ProgramMemory &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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return conditionIsFalse(condition->astOperand1(), programMemory) ||
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conditionIsFalse(condition->astOperand2(), programMemory);
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}
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ProgramMemory 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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bool conditionIsTrue(const Token *condition, const ProgramMemory &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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return conditionIsTrue(condition->astOperand1(), programMemory) ||
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conditionIsTrue(condition->astOperand2(), programMemory);
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}
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ProgramMemory 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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void programMemoryParseCondition(ProgramMemory& pm, const Token* tok, const Token* endTok, const Settings* settings, bool then)
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{
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if (Token::Match(tok, "==|>=|<=|<|>|!=")) {
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if (then && !Token::Match(tok, "==|>=|<=|<|>"))
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return;
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if (!then && !Token::Match(tok, "<|>|!="))
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return;
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ValueFlow::Value truevalue;
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ValueFlow::Value falsevalue;
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const Token* vartok = parseCompareInt(tok, truevalue, falsevalue, [&](const Token* t) -> std::vector<MathLib::bigint> {
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if (t->hasKnownIntValue())
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return {t->values().front().intvalue};
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MathLib::bigint result = 0;
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bool error = false;
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execute(t, &pm, &result, &error);
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if (!error)
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return {result};
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return std::vector<MathLib::bigint>{};
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});
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if (!vartok)
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return;
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if (vartok->exprId() == 0)
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return;
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if (!truevalue.isIntValue())
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return;
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if (endTok && isExpressionChanged(vartok, tok->next(), endTok, settings, true))
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return;
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pm.setIntValue(vartok->exprId(), then ? truevalue.intvalue : falsevalue.intvalue);
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} else if (Token::simpleMatch(tok, "!")) {
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programMemoryParseCondition(pm, tok->astOperand1(), endTok, settings, !then);
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} else if (then && Token::simpleMatch(tok, "&&")) {
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programMemoryParseCondition(pm, tok->astOperand1(), endTok, settings, then);
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programMemoryParseCondition(pm, tok->astOperand2(), endTok, settings, then);
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} else if (!then && Token::simpleMatch(tok, "||")) {
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programMemoryParseCondition(pm, tok->astOperand1(), endTok, settings, then);
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programMemoryParseCondition(pm, tok->astOperand2(), endTok, settings, then);
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} else if (tok->exprId() > 0) {
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if (then && !astIsPointer(tok) && !astIsBool(tok))
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return;
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if (endTok && isExpressionChanged(tok, tok->next(), endTok, settings, true))
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return;
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pm.setIntValue(tok->exprId(), then);
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}
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}
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static void fillProgramMemoryFromConditions(ProgramMemory& pm, const Scope* scope, const Token* endTok, const Settings* settings)
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{
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if (!scope)
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return;
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if (!scope->isLocal())
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return;
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assert(scope != scope->nestedIn);
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fillProgramMemoryFromConditions(pm, scope->nestedIn, endTok, settings);
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if (scope->type == Scope::eIf || scope->type == Scope::eWhile || scope->type == Scope::eElse || scope->type == Scope::eFor) {
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const Token* condTok = getCondTokFromEnd(scope->bodyEnd);
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if (!condTok)
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return;
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programMemoryParseCondition(pm, condTok, endTok, settings, scope->type != Scope::eElse);
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}
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}
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static void fillProgramMemoryFromConditions(ProgramMemory& pm, const Token* tok, const Settings* settings)
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{
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fillProgramMemoryFromConditions(pm, tok->scope(), tok, settings);
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}
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static void fillProgramMemoryFromAssignments(ProgramMemory& pm, const Token* tok, const ProgramMemory& state, const ProgramMemory::Map& vars)
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{
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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::simpleMatch(tok2, "=") || Token::Match(tok2->previous(), "%var% (|{")) && tok2->astOperand1() &&
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tok2->astOperand2()) {
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bool setvar = false;
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const Token* vartok = tok2->astOperand1();
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const Token* valuetok = tok2->astOperand2();
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for (const auto& p:vars) {
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if (p.first != vartok->exprId())
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continue;
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if (vartok == tok)
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continue;
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pm.setValue(vartok->exprId(), p.second);
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setvar = true;
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}
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if (!setvar) {
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if (!pm.hasValue(vartok->exprId())) {
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MathLib::bigint result = 0;
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bool error = false;
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execute(valuetok, &pm, &result, &error);
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if (!error)
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pm.setIntValue(vartok->exprId(), result);
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else
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pm.setUnknown(vartok->exprId());
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}
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}
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} else if (tok2->exprId() > 0 && Token::Match(tok2, ".|(|[|*|%var%") && !pm.hasValue(tok2->exprId()) &&
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isVariableChanged(tok2, 0, nullptr, true)) {
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pm.setUnknown(tok2->exprId());
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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(), state))
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tok2 = cond->previous();
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else if (cond && conditionIsTrue(cond->astOperand2(), state)) {
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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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}
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static void removeModifiedVars(ProgramMemory& pm, const Token* tok, const Token* origin)
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{
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for (auto i = pm.values.begin(), last = pm.values.end(); i != last;) {
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if (isVariableChanged(origin, tok, i->first, false, nullptr, true)) {
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i = pm.values.erase(i);
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} else {
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++i;
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}
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}
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}
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static ProgramMemory getInitialProgramState(const Token* tok,
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const Token* origin,
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const ProgramMemory::Map& vars = ProgramMemory::Map {})
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{
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ProgramMemory pm;
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if (origin) {
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fillProgramMemoryFromConditions(pm, origin, nullptr);
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const ProgramMemory state = pm;
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fillProgramMemoryFromAssignments(pm, tok, state, vars);
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removeModifiedVars(pm, tok, origin);
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}
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return pm;
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}
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void ProgramMemoryState::insert(const ProgramMemory &pm, const Token* origin)
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{
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if (origin)
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for (auto&& p:pm.values)
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origins.insert(std::make_pair(p.first, origin));
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state.insert(pm);
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}
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void ProgramMemoryState::replace(const ProgramMemory &pm, const Token* origin)
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{
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if (origin)
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for (auto&& p:pm.values)
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origins[p.first] = origin;
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state.replace(pm);
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}
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void ProgramMemoryState::addState(const Token* tok, const ProgramMemory::Map& vars)
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{
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ProgramMemory pm = state;
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fillProgramMemoryFromConditions(pm, tok, nullptr);
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for (const auto& p:vars) {
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nonneg int exprid = p.first;
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const ValueFlow::Value &value = p.second;
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pm.setValue(exprid, value);
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if (value.varId)
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pm.setIntValue(value.varId, value.varvalue);
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}
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ProgramMemory local = pm;
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fillProgramMemoryFromAssignments(pm, tok, local, vars);
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replace(pm, tok);
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}
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void ProgramMemoryState::assume(const Token* tok, bool b)
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{
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ProgramMemory pm = state;
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programMemoryParseCondition(pm, tok, nullptr, nullptr, b);
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insert(pm, tok);
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}
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void ProgramMemoryState::removeModifiedVars(const Token* tok)
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{
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for (auto i = state.values.begin(), last = state.values.end(); i != last;) {
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if (isVariableChanged(origins[i->first], tok, i->first, false, nullptr, true)) {
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origins.erase(i->first);
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i = state.values.erase(i);
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} else {
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++i;
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}
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}
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}
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ProgramMemory ProgramMemoryState::get(const Token *tok, const ProgramMemory::Map& vars) const
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{
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ProgramMemoryState local = *this;
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local.addState(tok, vars);
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local.removeModifiedVars(tok);
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return local.state;
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}
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ProgramMemory getProgramMemory(const Token *tok, const ProgramMemory::Map& vars)
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{
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ProgramMemory programMemory;
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for (const auto& p:vars) {
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const ValueFlow::Value &value = p.second;
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programMemory.replace(getInitialProgramState(tok, value.tokvalue));
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programMemory.replace(getInitialProgramState(tok, value.condition));
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}
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fillProgramMemoryFromConditions(programMemory, tok, nullptr);
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ProgramMemory state;
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for (const auto& p:vars) {
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nonneg int exprid = p.first;
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const ValueFlow::Value &value = p.second;
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programMemory.setValue(exprid, value);
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if (value.varId)
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programMemory.setIntValue(value.varId, value.varvalue);
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}
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state = programMemory;
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fillProgramMemoryFromAssignments(programMemory, tok, state, vars);
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return programMemory;
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}
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ProgramMemory getProgramMemory(const Token* tok, nonneg int exprid, const ValueFlow::Value& value)
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{
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ProgramMemory programMemory;
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programMemory.replace(getInitialProgramState(tok, value.tokvalue));
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programMemory.replace(getInitialProgramState(tok, value.condition));
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fillProgramMemoryFromConditions(programMemory, tok, nullptr);
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programMemory.setValue(exprid, value);
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if (value.varId)
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programMemory.setIntValue(value.varId, value.varvalue);
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const ProgramMemory state = programMemory;
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fillProgramMemoryFromAssignments(programMemory, tok, state, {{exprid, value}});
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return programMemory;
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}
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void execute(const Token *expr,
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ProgramMemory * const programMemory,
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MathLib::bigint *result,
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bool *error)
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{
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if (!expr)
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*error = true;
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else if (expr->hasKnownIntValue() && !expr->isAssignmentOp()) {
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*result = expr->values().front().intvalue;
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}
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else if (expr->isNumber()) {
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*result = MathLib::toLongNumber(expr->str());
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if (MathLib::isFloat(expr->str()))
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*error = true;
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}
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else if (expr->varId() > 0) {
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if (!programMemory->getIntValue(expr->varId(), result))
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*error = true;
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}
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else if (Token::Match(expr->tokAt(-3), "%var% . %name% (") && astIsContainer(expr->tokAt(-3))) {
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const Token* containerTok = expr->tokAt(-3);
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Library::Container::Yield yield = containerTok->valueType()->container->getYield(expr->strAt(-1));
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if (yield == Library::Container::Yield::SIZE) {
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if (!programMemory->getContainerSizeValue(containerTok->exprId(), result))
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*error = true;
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} else if (yield == Library::Container::Yield::EMPTY) {
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if (!programMemory->getContainerEmptyValue(containerTok->exprId(), result))
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*error = true;
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} else {
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*error = true;
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}
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}
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else if (expr->exprId() > 0 && programMemory->hasValue(expr->exprId())) {
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if (!programMemory->getIntValue(expr->exprId(), result))
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*error = true;
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}
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else if (expr->isComparisonOp()) {
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MathLib::bigint result1(0), result2(0);
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bool error1 = false;
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bool error2 = false;
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execute(expr->astOperand1(), programMemory, &result1, &error1);
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execute(expr->astOperand2(), programMemory, &result2, &error2);
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if (error1 && error2) {
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*error = true;
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} else if (error1 && !error2) {
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ValueFlow::Value v = inferCondition(expr->str(), expr->astOperand1(), result2);
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*error = !v.isKnown();
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*result = v.intvalue;
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} else if (!error1 && error2) {
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ValueFlow::Value v = inferCondition(expr->str(), result1, expr->astOperand2());
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*error = !v.isKnown();
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*result = v.intvalue;
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} else {
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if (expr->str() == "<")
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*result = result1 < result2;
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else if (expr->str() == "<=")
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*result = result1 <= result2;
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else if (expr->str() == ">")
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*result = result1 > result2;
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else if (expr->str() == ">=")
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*result = result1 >= result2;
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else if (expr->str() == "==")
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*result = result1 == result2;
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else if (expr->str() == "!=")
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*result = result1 != result2;
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}
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}
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else if (expr->isAssignmentOp()) {
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execute(expr->astOperand2(), programMemory, result, error);
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if (!expr->astOperand1() || !expr->astOperand1()->exprId())
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*error = true;
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if (*error)
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return;
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if (expr->str() == "=") {
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programMemory->setIntValue(expr->astOperand1()->exprId(), *result);
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return;
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}
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long long intValue;
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if (!programMemory->getIntValue(expr->astOperand1()->exprId(), &intValue)) {
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*error = true;
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return;
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}
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if (expr->str() == "+=")
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programMemory->setIntValue(expr->astOperand1()->exprId(), intValue + *result);
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else if (expr->str() == "-=")
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programMemory->setIntValue(expr->astOperand1()->exprId(), intValue - *result);
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else if (expr->str() == "*=")
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programMemory->setIntValue(expr->astOperand1()->exprId(), intValue * *result);
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else if (expr->str() == "/=" && *result != 0)
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programMemory->setIntValue(expr->astOperand1()->exprId(), intValue / *result);
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else if (expr->str() == "%=" && *result != 0)
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programMemory->setIntValue(expr->astOperand1()->exprId(), intValue % *result);
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else if (expr->str() == "&=")
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programMemory->setIntValue(expr->astOperand1()->exprId(), intValue & *result);
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else if (expr->str() == "|=")
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programMemory->setIntValue(expr->astOperand1()->exprId(), intValue | *result);
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else if (expr->str() == "^=")
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programMemory->setIntValue(expr->astOperand1()->exprId(), intValue ^ *result);
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}
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else if (Token::Match(expr, "++|--")) {
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if (!expr->astOperand1() || expr->astOperand1()->exprId() == 0)
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*error = true;
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else {
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long long intValue;
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if (!programMemory->getIntValue(expr->astOperand1()->exprId(), &intValue))
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*error = true;
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else {
|
|
if (intValue == 0 &&
|
|
expr->str() == "--" &&
|
|
expr->astOperand1()->variable() &&
|
|
expr->astOperand1()->variable()->isUnsigned())
|
|
*error = true; // overflow
|
|
*result = intValue + (expr->str() == "++" ? 1 : -1);
|
|
programMemory->setIntValue(expr->astOperand1()->exprId(), *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() == "*") {
|
|
if (result2 && (result1 > std::numeric_limits<MathLib::bigint>::max()/result2))
|
|
*error = true;
|
|
else
|
|
*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() == "<<") {
|
|
if (result2 < 0 || result1 < 0 || result2 >= MathLib::bigint_bits) { // don't perform UB
|
|
*error= true;
|
|
} else {
|
|
*result = result1 << result2;
|
|
}
|
|
} else if (expr->str() == ">>") {
|
|
if (result2 < 0 || result2 >= MathLib::bigint_bits) { // don't perform UB
|
|
*error=true;
|
|
} else {
|
|
*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;
|
|
}
|
|
}
|
|
|
|
else if (expr->str() == "||") {
|
|
execute(expr->astOperand1(), programMemory, result, error);
|
|
if (*result == 1 && *error == false)
|
|
*result = 1;
|
|
else 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()) {
|
|
const Token *tokvalue = nullptr;
|
|
if (!programMemory->getTokValue(expr->astOperand1()->exprId(), &tokvalue)) {
|
|
auto tokvalue_it = std::find_if(expr->astOperand1()->values().begin(),
|
|
expr->astOperand1()->values().end(),
|
|
std::mem_fn(&ValueFlow::Value::isTokValue));
|
|
if (tokvalue_it == expr->astOperand1()->values().end()) {
|
|
*error = true;
|
|
return;
|
|
}
|
|
tokvalue = tokvalue_it->tokvalue;
|
|
}
|
|
if (!tokvalue || !tokvalue->isLiteral()) {
|
|
*error = true;
|
|
return;
|
|
}
|
|
const std::string strValue = 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;
|
|
}
|