//---------------------------------------------------------------------------
// memset(p, y, 0 /* bytes to fill */) <- 2nd and 3rd arguments inverted
//---------------------------------------------------------------------------
void CheckFunctions::memsetZeroBytes()
{
// FIXME:
// Replace this with library configuration.
// For instance:
// <arg nr="3">
// <warn knownIntValue="0" severity="warning" msg="..."/>
// </arg>
if (!_settings->isEnabled(Settings::WARNING))
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];
for (const Token* tok = scope->classStart->next(); tok != scope->classEnd; tok = tok->next()) {
if (Token::Match(tok, "memset|wmemset (") && (numberOfArguments(tok)==3)) {
const std::vector<const Token *> &arguments = getArguments(tok);
if (WRONG_DATA(arguments.size() != 3U, tok))
continue;
const Token* lastParamTok = arguments[2];
if (lastParamTok->str() == "0")
memsetZeroBytesError(tok);
}
}
}
}
bool isVariableChangedByFunctionCall(const Token *tok, const Settings *settings, bool *inconclusive)
{
if (!tok)
return false;
// address of variable
const bool addressOf = Token::simpleMatch(tok->previous(), "&");
// passing variable to subfunction?
if (Token::Match(tok->tokAt(-2), ") & %name% [,)]") && Token::Match(tok->linkAt(-2)->previous(), "[,(] ("))
;
else if (Token::Match(tok->tokAt(addressOf?-2:-1), "[(,] &| %name% [,)]"))
;
else if (Token::Match(tok->tokAt(addressOf?-2:-1), "[?:] &| %name% [:,)]")) {
const Token *parent = tok->astParent();
if (parent == tok->previous() && parent->str() == "&")
parent = parent->astParent();
while (Token::Match(parent, "[?:]"))
parent = parent->astParent();
while (Token::simpleMatch(parent, ","))
parent = parent->astParent();
if (!parent || parent->str() != "(")
return false;
} else
return false;
// reinterpret_cast etc..
if (Token::Match(tok->tokAt(-3), "> ( & %name% ) [,)]") &&
tok->linkAt(-3) &&
Token::Match(tok->linkAt(-3)->tokAt(-2), "[,(] %type% <"))
tok = tok->linkAt(-3);
// goto start of function call and get argnr
unsigned int argnr = 0;
while (tok && tok->str() != "(") {
if (tok->str() == ",")
++argnr;
else if (tok->str() == ")")
tok = tok->link();
tok = tok->previous();
}
tok = tok ? tok->previous() : nullptr;
if (tok && tok->link() && tok->str() == ">")
tok = tok->link()->previous();
if (!Token::Match(tok, "%name% [(<]"))
return false; // not a function => variable not changed
// Constructor call
if (tok->variable() && tok->variable()->nameToken() == tok) {
// Find constructor..
const unsigned int argCount = numberOfArguments(tok);
const Scope *typeScope = tok->variable()->typeScope();
if (typeScope) {
for (std::list<Function>::const_iterator it = typeScope->functionList.begin(); it != typeScope->functionList.end(); ++it) {
if (!it->isConstructor() || it->argCount() < argCount)
continue;
const Variable *arg = it->getArgumentVar(argnr);
if (arg && arg->isReference() && !arg->isConst())
return true;
}
return false;
}
if (inconclusive)
*inconclusive = true;
return false;
}
if (!tok->function()) {
// if the library says 0 is invalid
// => it is assumed that parameter is an in parameter (TODO: this is a bad heuristic)
if (!addressOf && settings && settings->library.isnullargbad(tok, 1+argnr))
return false;
// addressOf => inconclusive
if (!addressOf) {
if (inconclusive != nullptr)
*inconclusive = true;
return false;
}
return true;
}
const Variable *arg = tok->function()->getArgumentVar(argnr);
if (addressOf) {
if (!(arg && arg->isConst()))
return true;
// If const is applied to the pointer, then the value can still be modified
if (arg && Token::simpleMatch(arg->typeEndToken(), "* const"))
return true;
}
return arg && !arg->isConst() && arg->isReference();
}
