// Return c_str
void CheckAutoVariables::returncstr()
{
// TODO: Move this to CheckStl::string_c_str
// locate function that returns a const char *..
const SymbolDatabase *symbolDatabase = _tokenizer->getSymbolDatabase();
std::list<Scope>::const_iterator scope;
for (scope = symbolDatabase->scopeList.begin(); scope != symbolDatabase->scopeList.end(); ++scope) {
// only check functions
if (scope->type != Scope::eFunction || !scope->function)
continue;
const Token *tok = scope->function->tokenDef;
// have we reached a function that returns a const char *
if (Token::simpleMatch(tok->tokAt(-3), "const char *")) {
for (const Token *tok2 = scope->classStart; tok2 && tok2 != scope->classEnd; tok2 = tok2->next()) {
// return pointer to temporary..
if (returnTemporary(tok2)) {
// report error..
errorReturnTempPointer(tok2);
}
}
}
}
}
void CheckAutoVariables::returnReference()
{
if (_tokenizer->isC())
return;
const SymbolDatabase *symbolDatabase = _tokenizer->getSymbolDatabase();
const std::size_t functions = symbolDatabase->functionScopes.size();
for (std::size_t i = 0; i < functions; ++i) {
const Scope * scope = symbolDatabase->functionScopes[i];
if (!scope->function)
continue;
const Token *tok = scope->function->tokenDef;
// have we reached a function that returns a reference?
if (tok->previous() && tok->previous()->str() == "&") {
for (const Token *tok2 = scope->classStart->next(); tok2 && tok2 != scope->classEnd; tok2 = tok2->next()) {
if (tok2->str() != "return")
continue;
// return..
if (Token::Match(tok2, "return %var% ;")) {
// is the returned variable a local variable?
if (isAutoVar(tok2->next())) {
const Variable *var1 = tok2->next()->variable();
// If reference variable is used, check what it references
if (Token::Match(var1->nameToken(), "%var% [=(]")) {
const Token *tok3 = var1->nameToken()->tokAt(2);
if (!Token::Match(tok3, "%var% [);.]"))
continue;
// Only report error if variable that is referenced is
// a auto variable
if (!isAutoVar(tok3))
continue;
}
// report error..
errorReturnReference(tok2);
}
}
// return reference to temporary..
else if (Token::Match(tok2, "return %var% (") &&
Token::simpleMatch(tok2->linkAt(2), ") ;")) {
if (returnTemporary(tok2->next())) {
// report error..
errorReturnTempReference(tok2);
}
}
// Return reference to a literal or the result of a calculation
else if (tok2->astOperand1() && (tok2->astOperand1()->isCalculation() || tok2->next()->isLiteral()) && astHasAutoResult(tok2->astOperand1())) {
errorReturnTempReference(tok2);
}
}
}
}
}
// Return c_str
void CheckAutoVariables::returncstr()
{
// locate function that returns a const char *..
const SymbolDatabase *symbolDatabase = _tokenizer->getSymbolDatabase();
std::list<Scope>::const_iterator scope;
for (scope = symbolDatabase->scopeList.begin(); scope != symbolDatabase->scopeList.end(); ++scope) {
// only check functions
if (scope->type != Scope::eFunction)
continue;
const Token *tok = scope->classDef;
// skip any qualification
while (Token::Match(tok->tokAt(-2), "%type% ::"))
tok = tok->tokAt(-2);
// have we reached a function that returns a const char *
if (Token::simpleMatch(tok->tokAt(-3), "const char *")) {
// go to the '('
const Token *tok2 = scope->classDef->next();
// go to the ')'
tok2 = tok2->next()->link();
unsigned int indentlevel = 0;
for (; tok2; tok2 = tok2->next()) {
// indentlevel..
if (tok2->str() == "{")
++indentlevel;
else if (tok2->str() == "}") {
if (indentlevel <= 1)
break;
--indentlevel;
}
// return..
if (Token::Match(tok2, "return %var% . c_str ( ) ;")) {
// is the returned variable a local variable?
const unsigned int varid = tok2->next()->varId();
const Variable *var = symbolDatabase->getVariableFromVarId(varid);
if (var && var->isLocal() && !var->isStatic()) {
// report error..
errorReturnAutocstr(tok2);
}
}
// return pointer to temporary..
else if (returnTemporary(tok2)) {
// report error..
errorReturnTempPointer(tok2);
}
}
}
}
}
void CheckAutoVariables::returnReference()
{
const SymbolDatabase *symbolDatabase = _tokenizer->getSymbolDatabase();
std::list<Scope>::const_iterator scope;
for (scope = symbolDatabase->scopeList.begin(); scope != symbolDatabase->scopeList.end(); ++scope) {
// only check functions
if (scope->type != Scope::eFunction)
continue;
const Token *tok = scope->classDef;
// skip any qualification
while (Token::Match(tok->tokAt(-2), "%type% ::"))
tok = tok->tokAt(-2);
// have we reached a function that returns a reference?
if (tok->previous() && tok->previous()->str() == "&") {
for (const Token *tok2 = scope->classStart; tok2 && tok2 != scope->classEnd; tok2 = tok2->next()) {
// return..
if (Token::Match(tok2, "return %var% ;")) {
// is the returned variable a local variable?
const unsigned int varid1 = tok2->next()->varId();
const Variable *var1 = symbolDatabase->getVariableFromVarId(varid1);
if (var1 && var1->isLocal() && !var1->isStatic()) {
// If reference variable is used, check what it references
if (Token::Match(var1->nameToken(), "%var% =")) {
const Token *tok3 = var1->nameToken()->tokAt(2);
if (!Token::Match(tok3, "%var% [;.]"))
continue;
// Only report error if variable that is referenced is
// a auto variable
const Variable *var2 = symbolDatabase->getVariableFromVarId(tok3->varId());
if (!var2 || !var2->isLocal() || var2->isStatic() || (var2->isPointer() && tok3->strAt(1) == "."))
continue;
}
// report error..
errorReturnReference(tok2);
}
}
// return reference to temporary..
else if (returnTemporary(tok2)) {
// report error..
errorReturnTempReference(tok2);
}
}
}
}
}
// Return c_str
void CheckAutoVariables::returncstr()
{
// locate function that returns a const char *..
for (const Token *tok = _tokenizer->tokens(); tok; tok = tok->next())
{
// Skip executable scopes..
if (Token::Match(tok, ") const| {"))
{
tok = tok->next();
if (tok->str() == "const")
tok = tok->next();
tok = tok->link();
continue;
}
// have we reached a function that returns a reference?
if (Token::Match(tok, "const char * %var% ("))
{
// go to the '('
const Token *tok2 = tok->tokAt(4);
// go to the ')'
tok2 = tok2->link();
// is this a function implementation?
if (Token::Match(tok2, ") const| {"))
{
unsigned int indentlevel = 0;
std::set<unsigned int> localvar; // local variables in function
while (0 != (tok2 = tok2->next()))
{
// indentlevel..
if (tok2->str() == "{")
++indentlevel;
else if (tok2->str() == "}")
{
if (indentlevel <= 1)
break;
--indentlevel;
}
// declare local variable..
if (Token::Match(tok2, "[{};] %type%") && tok2->next()->str() != "return")
{
// goto next token..
tok2 = tok2->next();
// skip "const"
if (Token::Match(tok2, "const %type%"))
tok2 = tok2->next();
// skip "std::" if it is seen
if (Token::simpleMatch(tok2, "std ::"))
tok2 = tok2->tokAt(2);
// is it a variable declaration?
if (Token::Match(tok2, "%type% %var% ;"))
localvar.insert(tok2->next()->varId());
}
// return..
else if (Token::Match(tok2, "return %var% . c_str ( ) ;"))
{
// is the returned variable a local variable?
if ((tok2->next()->varId() > 0) &&
(localvar.find(tok2->next()->varId()) != localvar.end()))
{
// report error..
errorReturnAutocstr(tok2);
}
}
// return pointer to temporary..
else if (returnTemporary(tok2))
{
// report error..
errorReturnTempPointer(tok2);
}
}
}
}
}
}
// FIXME: There should be no temporary destructor in C++17.
// CHECK: void returnByValueIntoVariable()
// CHECK: 1: returnTemporary
// CHECK-NEXT: 2: [B1.1] (ImplicitCastExpr, FunctionToPointerDecay, class return_stmt_with_dtor::D (*)(void))
// CXX11-ELIDE-NEXT: 3: [B1.2]() (CXXRecordTypedCall, [B1.4], [B1.6], [B1.7])
// CXX11-NOELIDE-NEXT: 3: [B1.2]() (CXXRecordTypedCall, [B1.4], [B1.6])
// CXX11-NEXT: 4: [B1.3] (BindTemporary)
// CXX11-NEXT: 5: [B1.4] (ImplicitCastExpr, NoOp, const class return_stmt_with_dtor::D)
// CXX11-NEXT: 6: [B1.5]
// CXX11-NEXT: 7: [B1.6] (CXXConstructExpr, [B1.8], class return_stmt_with_dtor::D)
// CXX11-NEXT: 8: return_stmt_with_dtor::D d = returnTemporary();
// CXX11-NEXT: 9: ~return_stmt_with_dtor::D() (Temporary object destructor)
// CXX11-NEXT: 10: [B1.8].~D() (Implicit destructor)
// CXX17-NEXT: 3: [B1.2]() (CXXRecordTypedCall, [B1.5], [B1.4])
// CXX17-NEXT: 4: [B1.3] (BindTemporary)
// CXX17-NEXT: 5: return_stmt_with_dtor::D d = returnTemporary();
// CXX17-NEXT: 6: ~return_stmt_with_dtor::D() (Temporary object destructor)
// CXX17-NEXT: 7: [B1.5].~D() (Implicit destructor)
void returnByValueIntoVariable() {
D d = returnTemporary();
}