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#include "programmemory.h"
#include "token.h"
#include "astutils.h"
#include "symboldatabase.h"
#include <algorithm>
#include <cassert>
#include <limits>
#include <memory>
void ProgramMemory::setValue(nonneg int varid, const ValueFlow::Value &value)
{
values[varid] = value;
}
const ValueFlow::Value* ProgramMemory::getValue(nonneg int varid) const
{
const ProgramMemory::Map::const_iterator it = values.find(varid);
const bool found = it != values.end() && !it->second.isImpossible();
if (found)
return &it->second;
else
return nullptr;
}
bool ProgramMemory::getIntValue(nonneg int varid, MathLib::bigint* result) const
{
const ValueFlow::Value* value = getValue(varid);
if (value && value->isIntValue()) {
*result = value->intvalue;
return true;
}
return false;
}
void ProgramMemory::setIntValue(nonneg int varid, MathLib::bigint value)
{
values[varid] = ValueFlow::Value(value);
}
bool ProgramMemory::getTokValue(nonneg int varid, const Token** result) const
{
const ValueFlow::Value* value = getValue(varid);
if (value && value->isTokValue()) {
*result = value->tokvalue;
return true;
}
return false;
}
bool ProgramMemory::getContainerSizeValue(nonneg int varid, MathLib::bigint* result) const
{
const ValueFlow::Value* value = getValue(varid);
if (value && value->isContainerSizeValue()) {
*result = value->intvalue;
return true;
}
return false;
}
void ProgramMemory::setUnknown(nonneg int varid)
{
values[varid].valueType = ValueFlow::Value::ValueType::UNINIT;
}
bool ProgramMemory::hasValue(nonneg int varid)
{
return values.find(varid) != values.end();
}
void ProgramMemory::swap(ProgramMemory &pm)
{
values.swap(pm.values);
}
void ProgramMemory::clear()
{
values.clear();
}
bool ProgramMemory::empty() const
{
return values.empty();
}
void ProgramMemory::replace(const ProgramMemory &pm)
{
for (auto&& p:pm.values)
values[p.first] = p.second;
}
void ProgramMemory::insert(const ProgramMemory &pm)
{
for (auto&& p:pm.values)
values.insert(p);
}
bool conditionIsFalse(const Token *condition, const ProgramMemory &programMemory)
{
if (!condition)
return false;
if (condition->str() == "&&") {
return conditionIsFalse(condition->astOperand1(), programMemory) ||
conditionIsFalse(condition->astOperand2(), programMemory);
}
ProgramMemory progmem(programMemory);
MathLib::bigint result = 0;
bool error = false;
execute(condition, &progmem, &result, &error);
return !error && result == 0;
}
bool conditionIsTrue(const Token *condition, const ProgramMemory &programMemory)
{
if (!condition)
return false;
if (condition->str() == "||") {
return conditionIsTrue(condition->astOperand1(), programMemory) ||
conditionIsTrue(condition->astOperand2(), programMemory);
}
ProgramMemory progmem(programMemory);
bool error = false;
MathLib::bigint result = 0;
execute(condition, &progmem, &result, &error);
return !error && result == 1;
}
static void programMemoryParseCondition(ProgramMemory& pm, const Token* tok, const Token* endTok, const Settings* settings, bool then)
{
if (Token::Match(tok, "==|>=|<=|<|>|!=")) {
if (then && !Token::Match(tok, "==|>=|<="))
return;
if (!then && !Token::Match(tok, "<|>|!="))
return;
ValueFlow::Value truevalue;
ValueFlow::Value falsevalue;
const Token* vartok = parseCompareInt(tok, truevalue, falsevalue);
if (!vartok)
return;
if (vartok->varId() == 0)
return;
if (!truevalue.isIntValue())
return;
if (endTok && isVariableChanged(tok->next(), endTok, vartok->varId(), false, settings, true))
return;
pm.setIntValue(vartok->varId(), then ? truevalue.intvalue : falsevalue.intvalue);
} else if (Token::Match(tok, "%var%")) {
if (tok->varId() == 0)
return;
if (then && !astIsPointer(tok) && !astIsBool(tok))
return;
if (endTok && isVariableChanged(tok->next(), endTok, tok->varId(), false, settings, true))
return;
pm.setIntValue(tok->varId(), then);
} else if (Token::simpleMatch(tok, "!")) {
programMemoryParseCondition(pm, tok->astOperand1(), endTok, settings, !then);
} else if (then && Token::simpleMatch(tok, "&&")) {
programMemoryParseCondition(pm, tok->astOperand1(), endTok, settings, then);
programMemoryParseCondition(pm, tok->astOperand2(), endTok, settings, then);
} else if (!then && Token::simpleMatch(tok, "||")) {
programMemoryParseCondition(pm, tok->astOperand1(), endTok, settings, then);
programMemoryParseCondition(pm, tok->astOperand2(), endTok, settings, then);
}
}
static void fillProgramMemoryFromConditions(ProgramMemory& pm, const Scope* scope, const Token* endTok, const Settings* settings)
{
if (!scope)
return;
if (!scope->isLocal())
return;
assert(scope != scope->nestedIn);
fillProgramMemoryFromConditions(pm, scope->nestedIn, endTok, settings);
if (scope->type == Scope::eIf || scope->type == Scope::eWhile || scope->type == Scope::eElse) {
const Token * bodyStart = scope->bodyStart;
if (scope->type == Scope::eElse) {
if (!Token::simpleMatch(bodyStart->tokAt(-2), "} else {"))
return;
bodyStart = bodyStart->linkAt(-2);
}
const Token * condEndTok = bodyStart->previous();
if (!Token::simpleMatch(condEndTok, ") {"))
return;
const Token * condStartTok = condEndTok->link();
if (!condStartTok)
return;
if (!Token::Match(condStartTok->previous(), "if|while ("))
return;
const Token * condTok = condStartTok->astOperand2();
programMemoryParseCondition(pm, condTok, endTok, settings, scope->type != Scope::eElse);
}
}
static void fillProgramMemoryFromConditions(ProgramMemory& pm, const Token* tok, const Settings* settings)
{
fillProgramMemoryFromConditions(pm, tok->scope(), tok, settings);
}
static void fillProgramMemoryFromAssignments(ProgramMemory& pm, const Token* tok, const ProgramMemory& state, ProgramMemory::Map vars)
{
int indentlevel = 0;
for (const Token *tok2 = tok; tok2; tok2 = tok2->previous()) {
bool setvar = false;
if (Token::Match(tok2, "[;{}] %var% = %var% ;")) {
for (auto&& p:vars) {
if (p.first != tok2->next()->varId())
continue;
const Token *vartok = tok2->tokAt(3);
if (vartok == tok)
continue;
pm.setValue(vartok->varId(), p.second);
setvar = true;
}
}
if (!setvar && (Token::Match(tok2, ";|{|}|%type% %var% =") ||
Token::Match(tok2, "[;{}] const| %type% %var% ("))) {
const Token *vartok = tok2->next();
while (vartok->next()->isName())
vartok = vartok->next();
if (!pm.hasValue(vartok->varId())) {
MathLib::bigint result = 0;
bool error = false;
execute(vartok->next()->astOperand2(), &pm, &result, &error);
if (!error)
pm.setIntValue(vartok->varId(), result);
else
pm.setUnknown(vartok->varId());
}
} else if (!setvar && Token::Match(tok2, "%var% !!=") && isVariableChanged(tok2, 0, nullptr, true)) {
const Token *vartok = tok2;
if (!pm.hasValue(vartok->varId()))
pm.setUnknown(vartok->varId());
}
if (tok2->str() == "{") {
if (indentlevel <= 0)
break;
--indentlevel;
}
if (tok2->str() == "}") {
const Token *cond = tok2->link();
cond = Token::simpleMatch(cond->previous(), ") {") ? cond->linkAt(-1) : nullptr;
if (cond && conditionIsFalse(cond->astOperand2(), state))
tok2 = cond->previous();
else if (cond && conditionIsTrue(cond->astOperand2(), state)) {
++indentlevel;
continue;
} else
break;
}
}
}
static void removeModifiedVars(ProgramMemory& pm, const Token* tok, const Token* origin)
{
for (auto i = pm.values.begin(), last = pm.values.end(); i != last;) {
if (isVariableChanged(origin, tok, i->first, false, nullptr, true)) {
i = pm.values.erase(i);
} else {
++i;
}
}
}
static ProgramMemory getInitialProgramState(const Token* tok,
const Token* origin,
const ProgramMemory::Map& vars = ProgramMemory::Map {})
{
ProgramMemory pm;
if (origin) {
fillProgramMemoryFromConditions(pm, origin, nullptr);
const ProgramMemory state = pm;
fillProgramMemoryFromAssignments(pm, tok, state, vars);
removeModifiedVars(pm, tok, origin);
}
return pm;
}
void ProgramMemoryState::insert(const ProgramMemory &pm, const Token* origin)
{
if (origin)
for (auto&& p:pm.values)
origins.insert(std::make_pair(p.first, origin));
state.insert(pm);
}
void ProgramMemoryState::replace(const ProgramMemory &pm, const Token* origin)
{
if (origin)
for (auto&& p:pm.values)
origins[p.first] = origin;
state.replace(pm);
}
void ProgramMemoryState::addState(const Token* tok, const ProgramMemory::Map& vars)
{
ProgramMemory pm;
fillProgramMemoryFromConditions(pm, tok, nullptr);
ProgramMemory local;
for (const auto& p:vars) {
nonneg int varid = p.first;
const ValueFlow::Value &value = p.second;
pm.setValue(varid, value);
if (value.varId)
pm.setIntValue(value.varId, value.varvalue);
}
local = pm;
fillProgramMemoryFromAssignments(pm, tok, local, vars);
replace(pm, tok);
}
void ProgramMemoryState::assume(const Token* tok, bool b)
{
ProgramMemory pm = state;
programMemoryParseCondition(pm, tok, nullptr, nullptr, b);
insert(pm, tok);
}
void ProgramMemoryState::removeModifiedVars(const Token* tok)
{
for (auto i = state.values.begin(), last = state.values.end(); i != last;) {
if (isVariableChanged(origins[i->first], tok, i->first, false, nullptr, true)) {
origins.erase(i->first);
i = state.values.erase(i);
} else {
++i;
}
}
}
ProgramMemory ProgramMemoryState::get(const Token *tok, const ProgramMemory::Map& vars) const
{
ProgramMemoryState local = *this;
local.addState(tok, vars);
local.removeModifiedVars(tok);
return local.state;
}
ProgramMemory getProgramMemory(const Token *tok, const ProgramMemory::Map& vars)
{
ProgramMemory programMemory;
for (const auto& p:vars) {
const ValueFlow::Value &value = p.second;
programMemory.replace(getInitialProgramState(tok, value.tokvalue));
programMemory.replace(getInitialProgramState(tok, value.condition));
}
fillProgramMemoryFromConditions(programMemory, tok, nullptr);
ProgramMemory state;
for (const auto& p:vars) {
nonneg int varid = p.first;
const ValueFlow::Value &value = p.second;
programMemory.setValue(varid, value);
if (value.varId)
programMemory.setIntValue(value.varId, value.varvalue);
}
state = programMemory;
fillProgramMemoryFromAssignments(programMemory, tok, state, vars);
return programMemory;
}
ProgramMemory getProgramMemory(const Token *tok, nonneg int varid, const ValueFlow::Value &value)
{
ProgramMemory programMemory;
programMemory.replace(getInitialProgramState(tok, value.tokvalue));
programMemory.replace(getInitialProgramState(tok, value.condition));
fillProgramMemoryFromConditions(programMemory, tok, nullptr);
programMemory.setValue(varid, value);
if (value.varId)
programMemory.setIntValue(value.varId, value.varvalue);
const ProgramMemory state = programMemory;
fillProgramMemoryFromAssignments(programMemory, tok, state, {{varid, value}});
return programMemory;
}
void execute(const Token *expr,
ProgramMemory * const programMemory,
MathLib::bigint *result,
bool *error)
{
if (!expr)
*error = true;
else if (expr->hasKnownIntValue()) {
*result = expr->values().front().intvalue;
}
else if (expr->isNumber()) {
*result = MathLib::toLongNumber(expr->str());
if (MathLib::isFloat(expr->str()))
*error = true;
}
else if (expr->varId() > 0) {
if (!programMemory->getIntValue(expr->varId(), result))
*error = true;
}
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->isAssignmentOp()) {
execute(expr->astOperand2(), programMemory, result, error);
if (!expr->astOperand1() || !expr->astOperand1()->varId())
*error = true;
if (*error)
return;
if (expr->str() == "=") {
programMemory->setIntValue(expr->astOperand1()->varId(), *result);
return;
}
long long intValue;
if (!programMemory->getIntValue(expr->astOperand1()->varId(), &intValue)) {
*error = true;
return;
}
if (expr->str() == "+=")
programMemory->setIntValue(expr->astOperand1()->varId(), intValue + *result);
else if (expr->str() == "-=")
programMemory->setIntValue(expr->astOperand1()->varId(), intValue - *result);
else if (expr->str() == "*=")
programMemory->setIntValue(expr->astOperand1()->varId(), intValue * *result);
else if (expr->str() == "/=" && *result != 0)
programMemory->setIntValue(expr->astOperand1()->varId(), intValue / *result);
else if (expr->str() == "%=" && *result != 0)
programMemory->setIntValue(expr->astOperand1()->varId(), intValue % *result);
else if (expr->str() == "&=")
programMemory->setIntValue(expr->astOperand1()->varId(), intValue & *result);
else if (expr->str() == "|=")
programMemory->setIntValue(expr->astOperand1()->varId(), intValue | *result);
else if (expr->str() == "^=")
programMemory->setIntValue(expr->astOperand1()->varId(), intValue ^ *result);
}
else if (Token::Match(expr, "++|--")) {
if (!expr->astOperand1() || expr->astOperand1()->varId() == 0U)
*error = true;
else {
long long intValue;
if (!programMemory->getIntValue(expr->astOperand1()->varId(), &intValue))
*error = true;
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()->varId(), *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) { // 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()->varId(), &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 if (Token::Match(expr->tokAt(-3), "%var% . %name% (")) {
const Token* containerTok = expr->tokAt(-3);
if (astIsContainer(containerTok)) {
Library::Container::Yield yield = containerTok->valueType()->container->getYield(expr->strAt(-1));
if (yield == Library::Container::Yield::SIZE) {
if (!programMemory->getContainerSizeValue(containerTok->varId(), result))
*error = true;
} else if (yield == Library::Container::Yield::EMPTY) {
MathLib::bigint size = 0;
if (!programMemory->getContainerSizeValue(containerTok->varId(), &size))
*error = true;
*result = (size == 0);
} else {
*error = true;
}
} else {
*error = true;
}
}
else
*error = true;
}
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