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checkstl.cpp
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/*
* Cppcheck - A tool for static C/C++ code analysis
* Copyright (C) 2007-2024 Cppcheck team.
*
* This program is free software: you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation, either version 3 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program. If not, see <http://www.gnu.org/licenses/>.
*/
#include "checkstl.h"
#include "astutils.h"
#include "errortypes.h"
#include "library.h"
#include "mathlib.h"
#include "pathanalysis.h"
#include "settings.h"
#include "standards.h"
#include "symboldatabase.h"
#include "token.h"
#include "tokenize.h"
#include "utils.h"
#include "valueflow.h"
#include "vfvalue.h"
#include "checknullpointer.h"
#include <algorithm>
#include <iterator>
#include <list>
#include <map>
#include <set>
#include <sstream>
#include <tuple>
#include <unordered_map>
#include <utility>
#include <vector>
// Register this check class (by creating a static instance of it)
namespace {
CheckStl instance;
}
// CWE IDs used:
static const CWE CWE398(398U); // Indicator of Poor Code Quality
static const CWE CWE597(597U); // Use of Wrong Operator in String Comparison
static const CWE CWE628(628U); // Function Call with Incorrectly Specified Arguments
static const CWE CWE664(664U); // Improper Control of a Resource Through its Lifetime
static const CWE CWE667(667U); // Improper Locking
static const CWE CWE704(704U); // Incorrect Type Conversion or Cast
static const CWE CWE762(762U); // Mismatched Memory Management Routines
static const CWE CWE786(786U); // Access of Memory Location Before Start of Buffer
static const CWE CWE788(788U); // Access of Memory Location After End of Buffer
static const CWE CWE825(825U); // Expired Pointer Dereference
static const CWE CWE833(833U); // Deadlock
static const CWE CWE834(834U); // Excessive Iteration
static bool isElementAccessYield(Library::Container::Yield yield)
{
return contains({Library::Container::Yield::ITEM, Library::Container::Yield::AT_INDEX}, yield);
}
static bool containerAppendsElement(const Library::Container* container, const Token* parent)
{
if (Token::Match(parent, ". %name% (")) {
const Library::Container::Action action = container->getAction(parent->strAt(1));
if (contains({Library::Container::Action::INSERT,
Library::Container::Action::APPEND,
Library::Container::Action::CHANGE,
Library::Container::Action::CHANGE_INTERNAL,
Library::Container::Action::PUSH,
Library::Container::Action::RESIZE},
action))
return true;
}
return false;
}
static bool containerYieldsElement(const Library::Container* container, const Token* parent)
{
if (Token::Match(parent, ". %name% (")) {
const Library::Container::Yield yield = container->getYield(parent->strAt(1));
if (isElementAccessYield(yield))
return true;
}
return false;
}
static bool containerPopsElement(const Library::Container* container, const Token* parent)
{
if (Token::Match(parent, ". %name% (")) {
const Library::Container::Action action = container->getAction(parent->strAt(1));
if (contains({ Library::Container::Action::POP }, action))
return true;
}
return false;
}
static const Token* getContainerIndex(const Library::Container* container, const Token* parent)
{
if (Token::Match(parent, ". %name% (")) {
const Library::Container::Yield yield = container->getYield(parent->strAt(1));
if (yield == Library::Container::Yield::AT_INDEX && !Token::simpleMatch(parent->tokAt(2), "( )"))
return parent->tokAt(2)->astOperand2();
}
if (!container->arrayLike_indexOp && !container->stdStringLike)
return nullptr;
if (Token::simpleMatch(parent, "["))
return parent->astOperand2();
return nullptr;
}
static const Token* getContainerFromSize(const Library::Container* container, const Token* tok)
{
if (!tok)
return nullptr;
if (Token::Match(tok->tokAt(-2), ". %name% (")) {
const Library::Container::Yield yield = container->getYield(tok->strAt(-1));
if (yield == Library::Container::Yield::SIZE)
return tok->tokAt(-2)->astOperand1();
}
return nullptr;
}
void CheckStl::outOfBounds()
{
logChecker("CheckStl::outOfBounds");
for (const Scope *function : mTokenizer->getSymbolDatabase()->functionScopes) {
for (const Token *tok = function->bodyStart; tok != function->bodyEnd; tok = tok->next()) {
const Library::Container *container = getLibraryContainer(tok);
if (!container || container->stdAssociativeLike)
continue;
const Token * parent = astParentSkipParens(tok);
const Token* accessTok = parent;
if (Token::simpleMatch(accessTok, ".") && Token::simpleMatch(accessTok->astParent(), "("))
accessTok = accessTok->astParent();
if (astIsIterator(accessTok) && Token::simpleMatch(accessTok->astParent(), "+"))
accessTok = accessTok->astParent();
const Token* indexTok = getContainerIndex(container, parent);
if (indexTok == tok)
continue;
for (const ValueFlow::Value &value : tok->values()) {
if (!value.isContainerSizeValue())
continue;
if (value.isImpossible())
continue;
if (value.isInconclusive() && !mSettings->certainty.isEnabled(Certainty::inconclusive))
continue;
if (!value.errorSeverity() && !mSettings->severity.isEnabled(Severity::warning))
continue;
if (value.intvalue == 0 && (indexTok ||
(containerYieldsElement(container, parent) && !containerAppendsElement(container, parent)) ||
containerPopsElement(container, parent))) {
std::string indexExpr;
if (indexTok && !indexTok->hasKnownValue())
indexExpr = indexTok->expressionString();
outOfBoundsError(accessTok, tok->expressionString(), &value, indexExpr, nullptr);
continue;
}
if (indexTok) {
std::vector<ValueFlow::Value> indexValues =
ValueFlow::isOutOfBounds(value, indexTok, mSettings->severity.isEnabled(Severity::warning));
if (!indexValues.empty()) {
outOfBoundsError(
accessTok, tok->expressionString(), &value, indexTok->expressionString(), &indexValues.front());
continue;
}
}
}
if (indexTok && !indexTok->hasKnownIntValue()) {
const ValueFlow::Value* value =
ValueFlow::findValue(indexTok->values(), *mSettings, [&](const ValueFlow::Value& v) {
if (!v.isSymbolicValue())
return false;
if (v.isImpossible())
return false;
if (v.intvalue < 0)
return false;
const Token* sizeTok = v.tokvalue;
if (sizeTok && sizeTok->isCast())
sizeTok = sizeTok->astOperand2() ? sizeTok->astOperand2() : sizeTok->astOperand1();
const Token* containerTok = getContainerFromSize(container, sizeTok);
if (!containerTok)
return false;
return containerTok->exprId() == tok->exprId();
});
if (!value)
continue;
outOfBoundsError(accessTok, tok->expressionString(), nullptr, indexTok->expressionString(), value);
}
}
}
}
static std::string indexValueString(const ValueFlow::Value& indexValue, const std::string& containerName = emptyString)
{
if (indexValue.isIteratorStartValue())
return "at position " + MathLib::toString(indexValue.intvalue) + " from the beginning";
if (indexValue.isIteratorEndValue())
return "at position " + MathLib::toString(-indexValue.intvalue) + " from the end";
std::string indexString = MathLib::toString(indexValue.intvalue);
if (indexValue.isSymbolicValue()) {
indexString = containerName + ".size()";
if (indexValue.intvalue != 0)
indexString += "+" + MathLib::toString(indexValue.intvalue);
}
if (indexValue.bound == ValueFlow::Value::Bound::Lower)
return "greater or equal to " + indexString;
return indexString;
}
void CheckStl::outOfBoundsError(const Token *tok, const std::string &containerName, const ValueFlow::Value *containerSize, const std::string &index, const ValueFlow::Value *indexValue)
{
// Do not warn if both the container size and index value are possible
if (containerSize && indexValue && containerSize->isPossible() && indexValue->isPossible())
return;
const std::string expression = tok ? tok->expressionString() : (containerName+"[x]");
std::string errmsg;
if (!containerSize) {
if (indexValue && indexValue->condition)
errmsg = ValueFlow::eitherTheConditionIsRedundant(indexValue->condition) + " or '" + index +
"' can have the value " + indexValueString(*indexValue, containerName) + ". Expression '" +
expression + "' causes access out of bounds.";
else
errmsg = "Out of bounds access in expression '" + expression + "'";
} else if (containerSize->intvalue == 0) {
if (containerSize->condition)
errmsg = ValueFlow::eitherTheConditionIsRedundant(containerSize->condition) + " or expression '" + expression + "' causes access out of bounds.";
else if (indexValue == nullptr && !index.empty() && tok->valueType() && tok->valueType()->type == ValueType::ITERATOR)
errmsg = "Out of bounds access in expression '" + expression + "' because '$symbol' is empty and '" + index + "' may be non-zero.";
else
errmsg = "Out of bounds access in expression '" + expression + "' because '$symbol' is empty.";
} else if (indexValue) {
if (containerSize->condition)
errmsg = ValueFlow::eitherTheConditionIsRedundant(containerSize->condition) + " or size of '$symbol' can be " + MathLib::toString(containerSize->intvalue) + ". Expression '" + expression + "' causes access out of bounds.";
else if (indexValue->condition)
errmsg = ValueFlow::eitherTheConditionIsRedundant(indexValue->condition) + " or '" + index + "' can have the value " + indexValueString(*indexValue) + ". Expression '" + expression + "' causes access out of bounds.";
else
errmsg = "Out of bounds access in '" + expression + "', if '$symbol' size is " + MathLib::toString(containerSize->intvalue) + " and '" + index + "' is " + indexValueString(*indexValue);
} else {
// should not happen
return;
}
ErrorPath errorPath;
if (!indexValue)
errorPath = getErrorPath(tok, containerSize, "Access out of bounds");
else {
ErrorPath errorPath1 = getErrorPath(tok, containerSize, "Access out of bounds");
ErrorPath errorPath2 = getErrorPath(tok, indexValue, "Access out of bounds");
if (errorPath1.size() <= 1)
errorPath = std::move(errorPath2);
else if (errorPath2.size() <= 1)
errorPath = std::move(errorPath1);
else {
errorPath = std::move(errorPath1);
errorPath.splice(errorPath.end(), errorPath2);
}
}
reportError(errorPath,
(containerSize && !containerSize->errorSeverity()) || (indexValue && !indexValue->errorSeverity()) ? Severity::warning : Severity::error,
"containerOutOfBounds",
"$symbol:" + containerName +"\n" + errmsg,
CWE398,
(containerSize && containerSize->isInconclusive()) || (indexValue && indexValue->isInconclusive()) ? Certainty::inconclusive : Certainty::normal);
}
bool CheckStl::isContainerSize(const Token *containerToken, const Token *expr) const
{
if (!Token::simpleMatch(expr, "( )"))
return false;
if (!Token::Match(expr->astOperand1(), ". %name% ("))
return false;
if (!isSameExpression(false, containerToken, expr->astOperand1()->astOperand1(), *mSettings, false, false))
return false;
return containerToken->valueType()->container->getYield(expr->strAt(-1)) == Library::Container::Yield::SIZE;
}
bool CheckStl::isContainerSizeGE(const Token * containerToken, const Token *expr) const
{
if (!expr)
return false;
if (isContainerSize(containerToken, expr))
return true;
if (expr->str() == "*") {
const Token *mul;
if (isContainerSize(containerToken, expr->astOperand1()))
mul = expr->astOperand2();
else if (isContainerSize(containerToken, expr->astOperand2()))
mul = expr->astOperand1();
else
return false;
return mul && (!mul->hasKnownIntValue() || mul->values().front().intvalue != 0);
}
if (expr->str() == "+") {
const Token *op;
if (isContainerSize(containerToken, expr->astOperand1()))
op = expr->astOperand2();
else if (isContainerSize(containerToken, expr->astOperand2()))
op = expr->astOperand1();
else
return false;
return op && op->getValueGE(0, *mSettings);
}
return false;
}
void CheckStl::outOfBoundsIndexExpression()
{
logChecker("CheckStl::outOfBoundsIndexExpression");
for (const Scope *function : mTokenizer->getSymbolDatabase()->functionScopes) {
for (const Token *tok = function->bodyStart; tok != function->bodyEnd; tok = tok->next()) {
if (!tok->isName() || !tok->valueType())
continue;
const Library::Container *container = tok->valueType()->container;
if (!container)
continue;
if (!container->arrayLike_indexOp && !container->stdStringLike)
continue;
if (!Token::Match(tok, "%name% ["))
continue;
if (isContainerSizeGE(tok, tok->next()->astOperand2()))
outOfBoundsIndexExpressionError(tok, tok->next()->astOperand2());
}
}
}
void CheckStl::outOfBoundsIndexExpressionError(const Token *tok, const Token *index)
{
const std::string varname = tok ? tok->str() : std::string("var");
const std::string i = index ? index->expressionString() : (varname + ".size()");
std::string errmsg = "Out of bounds access of $symbol, index '" + i + "' is out of bounds.";
reportError(tok,
Severity::error,
"containerOutOfBoundsIndexExpression",
"$symbol:" + varname +"\n" + errmsg,
CWE398,
Certainty::normal);
}
// Error message for bad iterator usage..
void CheckStl::invalidIteratorError(const Token *tok, const std::string &iteratorName)
{
reportError(tok, Severity::error, "invalidIterator1", "$symbol:"+iteratorName+"\nInvalid iterator: $symbol", CWE664, Certainty::normal);
}
void CheckStl::iteratorsError(const Token* tok, const std::string& containerName1, const std::string& containerName2)
{
reportError(tok, Severity::error, "iterators1",
"$symbol:" + containerName1 + "\n"
"$symbol:" + containerName2 + "\n"
"Same iterator is used with different containers '" + containerName1 + "' and '" + containerName2 + "'.", CWE664, Certainty::normal);
}
void CheckStl::iteratorsError(const Token* tok, const Token* containerTok, const std::string& containerName1, const std::string& containerName2)
{
std::list<const Token*> callstack = { tok, containerTok };
reportError(callstack, Severity::error, "iterators2",
"$symbol:" + containerName1 + "\n"
"$symbol:" + containerName2 + "\n"
"Same iterator is used with different containers '" + containerName1 + "' and '" + containerName2 + "'.", CWE664, Certainty::normal);
}
void CheckStl::iteratorsError(const Token* tok, const Token* containerTok, const std::string& containerName)
{
std::list<const Token*> callstack = { tok, containerTok };
reportError(callstack,
Severity::error,
"iterators3",
"$symbol:" + containerName +
"\n"
"Same iterator is used with containers '$symbol' that are temporaries or defined in different scopes.",
CWE664,
Certainty::normal);
}
// Error message used when dereferencing an iterator that has been erased..
void CheckStl::dereferenceErasedError(const Token *erased, const Token* deref, const std::string &itername, bool inconclusive)
{
if (erased) {
std::list<const Token*> callstack = { deref, erased };
reportError(callstack, Severity::error, "eraseDereference",
"$symbol:" + itername + "\n"
"Iterator '$symbol' used after element has been erased.\n"
"The iterator '$symbol' is invalid after the element it pointed to has been erased. "
"Dereferencing or comparing it with another iterator is invalid operation.", CWE664, inconclusive ? Certainty::inconclusive : Certainty::normal);
} else {
reportError(deref, Severity::error, "eraseDereference",
"$symbol:" + itername + "\n"
"Invalid iterator '$symbol' used.\n"
"The iterator '$symbol' is invalid before being assigned. "
"Dereferencing or comparing it with another iterator is invalid operation.", CWE664, inconclusive ? Certainty::inconclusive : Certainty::normal);
}
}
static const Token *skipMembers(const Token *tok)
{
while (Token::Match(tok, "%name% ."))
tok = tok->tokAt(2);
return tok;
}
static bool isIterator(const Variable *var, bool& inconclusiveType)
{
// Check that its an iterator
if (!var || !var->isLocal() || !Token::Match(var->typeEndToken(), "iterator|const_iterator|reverse_iterator|const_reverse_iterator|auto"))
return false;
inconclusiveType = false;
if (var->typeEndToken()->str() == "auto")
return (var->nameToken()->valueType() && var->nameToken()->valueType()->type == ValueType::Type::ITERATOR);
if (var->type()) { // If it is defined, ensure that it is defined like an iterator
// look for operator* and operator++
const Function* end = var->type()->getFunction("operator*");
const Function* incOperator = var->type()->getFunction("operator++");
if (!end || end->argCount() > 0 || !incOperator)
return false;
inconclusiveType = true; // heuristics only
}
return true;
}
static std::string getContainerName(const Token *containerToken)
{
if (!containerToken)
return std::string();
std::string ret(containerToken->str());
for (const Token *nametok = containerToken; nametok; nametok = nametok->tokAt(-2)) {
if (!Token::Match(nametok->tokAt(-2), "%name% ."))
break;
ret = nametok->strAt(-2) + '.' + ret;
}
return ret;
}
static bool isVector(const Token* tok)
{
if (!tok)
return false;
const Variable *var = tok->variable();
const Token *decltok = var ? var->typeStartToken() : nullptr;
return Token::simpleMatch(decltok, "std :: vector");
}
void CheckStl::iterators()
{
logChecker("CheckStl::iterators");
const SymbolDatabase *symbolDatabase = mTokenizer->getSymbolDatabase();
// Filling map of iterators id and their scope begin
std::map<int, const Token*> iteratorScopeBeginInfo;
for (const Variable* var : symbolDatabase->variableList()) {
bool inconclusiveType=false;
if (!isIterator(var, inconclusiveType))
continue;
const int iteratorId = var->declarationId();
if (iteratorId != 0)
iteratorScopeBeginInfo[iteratorId] = var->nameToken();
}
for (const Variable* var : symbolDatabase->variableList()) {
bool inconclusiveType=false;
if (!isIterator(var, inconclusiveType))
continue;
if (inconclusiveType && !mSettings->certainty.isEnabled(Certainty::inconclusive))
continue;
const int iteratorId = var->declarationId();
// the validIterator flag says if the iterator has a valid value or not
bool validIterator = Token::Match(var->nameToken()->next(), "[(=:{[]");
const Scope* invalidationScope = nullptr;
// The container this iterator can be used with
const Token* containerToken = nullptr;
const Scope* containerAssignScope = nullptr;
// When "validatingToken" is reached the validIterator is set to true
const Token* validatingToken = nullptr;
const Token* eraseToken = nullptr;
// Scan through the rest of the code and see if the iterator is
// used against other containers.
for (const Token *tok2 = var->nameToken(); tok2 && tok2 != var->scope()->bodyEnd; tok2 = tok2->next()) {
if (invalidationScope && tok2 == invalidationScope->bodyEnd)
validIterator = true; // Assume that the iterator becomes valid again
if (containerAssignScope && tok2 == containerAssignScope->bodyEnd)
containerToken = nullptr; // We don't know which containers might be used with the iterator
if (tok2 == validatingToken) {
validIterator = true;
eraseToken = nullptr;
invalidationScope = nullptr;
}
// Is the iterator used in a insert/erase operation?
if (Token::Match(tok2, "%name% . insert|erase ( *| %varid% )|,", iteratorId) && !isVector(tok2)) {
const Token* itTok = tok2->tokAt(4);
if (itTok->str() == "*") {
if (tok2->strAt(2) == "insert")
continue;
itTok = itTok->next();
}
// It is bad to insert/erase an invalid iterator
if (!validIterator)
invalidIteratorError(tok2, itTok->str());
// If insert/erase is used on different container then
// report an error
if (containerToken && tok2->varId() != containerToken->varId()) {
// skip error message if container is a set..
const Variable *variableInfo = tok2->variable();
const Token *decltok = variableInfo ? variableInfo->typeStartToken() : nullptr;
if (Token::simpleMatch(decltok, "std :: set"))
continue; // No warning
// skip error message if the iterator is erased/inserted by value
if (itTok->strAt(-1) == "*")
continue;
// inserting iterator range..
if (tok2->strAt(2) == "insert") {
const Token *par2 = itTok->nextArgument();
if (!par2 || par2->nextArgument())
continue;
while (par2->str() != ")") {
if (par2->varId() == containerToken->varId())
break;
bool inconclusiveType2=false;
if (isIterator(par2->variable(), inconclusiveType2))
break; // TODO: check if iterator points at same container
if (par2->str() == "(")
par2 = par2->link();
par2 = par2->next();
}
if (par2->str() != ")")
continue;
}
// Not different containers if a reference is used..
if (containerToken && containerToken->variable() && containerToken->variable()->isReference()) {
const Token *nameToken = containerToken->variable()->nameToken();
if (Token::Match(nameToken, "%name% =")) {
const Token *name1 = nameToken->tokAt(2);
const Token *name2 = tok2;
while (Token::Match(name1, "%name%|.|::") && name2 && name1->str() == name2->str()) {
name1 = name1->next();
name2 = name2->next();
}
if (!Token::simpleMatch(name1, ";") || !Token::Match(name2, "[;,()=]"))
continue;
}
}
// Show error message, mismatching iterator is used.
iteratorsError(tok2, getContainerName(containerToken), getContainerName(tok2));
}
// invalidate the iterator if it is erased
else if (tok2->strAt(2) == "erase" && (tok2->strAt(4) != "*" || (containerToken && tok2->varId() == containerToken->varId()))) {
validIterator = false;
eraseToken = tok2;
invalidationScope = tok2->scope();
}
// skip the operation
tok2 = itTok->next();
}
// it = foo.erase(..
// taking the result of an erase is ok
else if (Token::Match(tok2, "%varid% = %name% .", iteratorId) &&
Token::simpleMatch(skipMembers(tok2->tokAt(2)), "erase (")) {
// the returned iterator is valid
validatingToken = skipMembers(tok2->tokAt(2))->linkAt(1);
tok2 = validatingToken->link();
}
// Reassign the iterator
else if (Token::Match(tok2, "%varid% = %name% .", iteratorId) &&
Token::Match(skipMembers(tok2->tokAt(2)), "begin|rbegin|cbegin|crbegin|find (")) {
validatingToken = skipMembers(tok2->tokAt(2))->linkAt(1);
containerToken = skipMembers(tok2->tokAt(2))->tokAt(-2);
if (containerToken->varId() == 0 || Token::simpleMatch(validatingToken, ") ."))
containerToken = nullptr;
containerAssignScope = tok2->scope();
// skip ahead
tok2 = validatingToken->link();
}
// Reassign the iterator
else if (Token::Match(tok2, "%varid% =", iteratorId)) {
break;
}
// Passing iterator to function. Iterator might be initialized
else if (Token::Match(tok2, "%varid% ,|)", iteratorId)) {
validIterator = true;
}
// Dereferencing invalid iterator?
else if (!validIterator && Token::Match(tok2, "* %varid%", iteratorId)) {
dereferenceErasedError(eraseToken, tok2, tok2->strAt(1), inconclusiveType);
tok2 = tok2->next();
} else if (!validIterator && Token::Match(tok2, "%varid% . %name%", iteratorId)) {
dereferenceErasedError(eraseToken, tok2, tok2->str(), inconclusiveType);
tok2 = tok2->tokAt(2);
}
// bailout handling. Assume that the iterator becomes valid if we see return/break.
// TODO: better handling
else if (tok2->scope() == invalidationScope && Token::Match(tok2, "return|break|continue")) {
validatingToken = Token::findsimplematch(tok2->next(), ";");
}
// bailout handling. Assume that the iterator becomes valid if we see else.
// TODO: better handling
else if (tok2->str() == "else") {
validIterator = true;
}
}
}
}
void CheckStl::mismatchingContainerIteratorError(const Token* containerTok, const Token* iterTok, const Token* containerTok2)
{
const std::string container(containerTok ? containerTok->expressionString() : std::string("v1"));
const std::string container2(containerTok2 ? containerTok2->expressionString() : std::string("v2"));
const std::string iter(iterTok ? iterTok->expressionString() : std::string("it"));
reportError(containerTok,
Severity::error,
"mismatchingContainerIterator",
"Iterator '" + iter + "' referring to container '" + container2 + "' is used with container '" + container + "'.",
CWE664,
Certainty::normal);
}
// Error message for bad iterator usage..
void CheckStl::mismatchingContainersError(const Token* tok1, const Token* tok2)
{
const std::string expr1(tok1 ? tok1->expressionString() : std::string("v1"));
const std::string expr2(tok2 ? tok2->expressionString() : std::string("v2"));
reportError(tok1,
Severity::error,
"mismatchingContainers",
"Iterators of different containers '" + expr1 + "' and '" + expr2 + "' are used together.",
CWE664,
Certainty::normal);
}
void CheckStl::mismatchingContainerExpressionError(const Token *tok1, const Token *tok2)
{
const std::string expr1(tok1 ? tok1->expressionString() : std::string("v1"));
const std::string expr2(tok2 ? tok2->expressionString() : std::string("v2"));
reportError(tok1, Severity::warning, "mismatchingContainerExpression",
"Iterators to containers from different expressions '" +
expr1 + "' and '" + expr2 + "' are used together.", CWE664, Certainty::normal);
}
void CheckStl::sameIteratorExpressionError(const Token *tok)
{
reportError(tok, Severity::style, "sameIteratorExpression", "Same iterators expression are used for algorithm.", CWE664, Certainty::normal);
}
static std::vector<const Token*> getAddressContainer(const Token* tok)
{
if (Token::simpleMatch(tok, "[") && tok->astOperand1())
return { tok->astOperand1() };
while (Token::simpleMatch(tok, "::") && tok->astOperand2())
tok = tok->astOperand2();
std::vector<ValueFlow::Value> values = ValueFlow::getLifetimeObjValues(tok, /*inconclusive*/ false);
std::vector<const Token*> res;
for (const auto& v : values) {
if (v.tokvalue)
res.emplace_back(v.tokvalue);
}
if (res.empty())
res.emplace_back(tok);
return res;
}
static bool isSameIteratorContainerExpression(const Token* tok1,
const Token* tok2,
const Settings& settings,
ValueFlow::Value::LifetimeKind kind = ValueFlow::Value::LifetimeKind::Iterator)
{
if (isSameExpression(false, tok1, tok2, settings, false, false)) {
return !astIsContainerOwned(tok1) || !isTemporary(tok1, &settings.library);
}
if (astContainerYield(tok2) == Library::Container::Yield::ITEM)
return true;
if (kind == ValueFlow::Value::LifetimeKind::Address || kind == ValueFlow::Value::LifetimeKind::Iterator) {
const auto address1 = getAddressContainer(tok1);
const auto address2 = getAddressContainer(tok2);
return std::any_of(address1.begin(), address1.end(), [&](const Token* tok1) {
return std::any_of(address2.begin(), address2.end(), [&](const Token* tok2) {
return isSameExpression(false, tok1, tok2, settings, false, false);
});
});
}
return false;
}
// First it groups the lifetimes together using std::partition with the lifetimes that refer to the same token or token of a subexpression.
// Then it finds the lifetime in that group that refers to the "highest" parent using std::min_element and adds that to the vector.
static std::vector<ValueFlow::Value> pruneLifetimes(std::vector<ValueFlow::Value> lifetimes)
{
std::vector<ValueFlow::Value> result;
auto start = lifetimes.begin();
while (start != lifetimes.end())
{
const Token* tok1 = start->tokvalue;
auto it = std::partition(start, lifetimes.end(), [&](const ValueFlow::Value& v) {
const Token* tok2 = v.tokvalue;
return start->lifetimeKind == v.lifetimeKind && (astHasToken(tok1, tok2) || astHasToken(tok2, tok1));
});
auto root = std::min_element(start, it, [](const ValueFlow::Value& x, const ValueFlow::Value& y) {
return x.tokvalue != y.tokvalue && astHasToken(x.tokvalue, y.tokvalue);
});
result.push_back(*root);
start = it;
}
return result;
}
static ValueFlow::Value getLifetimeIteratorValue(const Token* tok, MathLib::bigint path = 0)
{
auto findIterVal = [](const std::vector<ValueFlow::Value>& values, const std::vector<ValueFlow::Value>::const_iterator beg) {
return std::find_if(beg, values.cend(), [](const ValueFlow::Value& v) {
return v.lifetimeKind == ValueFlow::Value::LifetimeKind::Iterator;
});
};
std::vector<ValueFlow::Value> values = pruneLifetimes(ValueFlow::getLifetimeObjValues(tok, false, path));
auto it = findIterVal(values, values.begin());
if (it != values.end()) {
auto it2 = findIterVal(values, it + 1);
if (it2 == values.cend())
return *it;
}
if (values.size() == 1)
return values.front();
return ValueFlow::Value{};
}
bool CheckStl::checkIteratorPair(const Token* tok1, const Token* tok2)
{
if (!tok1)
return false;
if (!tok2)
return false;
ValueFlow::Value val1 = getLifetimeIteratorValue(tok1);
ValueFlow::Value val2 = getLifetimeIteratorValue(tok2);
if (val1.tokvalue && val2.tokvalue && val1.lifetimeKind == val2.lifetimeKind) {
if (val1.lifetimeKind == ValueFlow::Value::LifetimeKind::Lambda)
return false;
if (tok1->astParent() == tok2->astParent() && Token::Match(tok1->astParent(), "%comp%|-")) {
if (val1.lifetimeKind == ValueFlow::Value::LifetimeKind::Address)
return false;
if (val1.lifetimeKind == ValueFlow::Value::LifetimeKind::Object &&
(!astIsContainer(val1.tokvalue) || !astIsContainer(val2.tokvalue)))
return false;
}
if (isSameIteratorContainerExpression(val1.tokvalue, val2.tokvalue, *mSettings, val1.lifetimeKind))
return false;
if (val1.tokvalue->expressionString() == val2.tokvalue->expressionString())
iteratorsError(tok1, val1.tokvalue, val1.tokvalue->expressionString());
else
mismatchingContainersError(val1.tokvalue, val2.tokvalue);
return true;
}
if (Token::Match(tok1->astParent(), "%comp%|-")) {
if (astIsIntegral(tok1, true) || astIsIntegral(tok2, true) ||
astIsFloat(tok1, true) || astIsFloat(tok2, true))
return false;
}
const Token* iter1 = getIteratorExpression(tok1);
if (!iter1)
return false;
const Token* iter2 = getIteratorExpression(tok2);
if (!iter2)
return false;
if (!isSameIteratorContainerExpression(iter1, iter2, *mSettings)) {
mismatchingContainerExpressionError(iter1, iter2);
return true;
}
return false;
}
namespace {
struct ArgIteratorInfo {
const Token* tok;
const Library::ArgumentChecks::IteratorInfo* info;
};
}
void CheckStl::mismatchingContainers()
{
logChecker("CheckStl::misMatchingContainers");
// Check if different containers are used in various calls of standard functions
const SymbolDatabase *symbolDatabase = mTokenizer->getSymbolDatabase();
for (const Scope * scope : symbolDatabase->functionScopes) {
for (const Token* tok = scope->bodyStart->next(); tok != scope->bodyEnd; tok = tok->next()) {
if (Token::Match(tok, "%comp%|-")) {
if (checkIteratorPair(tok->astOperand1(), tok->astOperand2()))
continue;
}
if (!Token::Match(tok, "%name% ( !!)"))
continue;
const Token * const ftok = tok;
const std::vector<const Token *> args = getArguments(ftok);
if (args.size() < 2)
continue;
// Group args together by container
std::map<int, std::vector<ArgIteratorInfo>> containers;
for (int argnr = 1; argnr <= args.size(); ++argnr) {
const Library::ArgumentChecks::IteratorInfo *i = mSettings->library.getArgIteratorInfo(ftok, argnr);
if (!i)
continue;
const Token * const argTok = args[argnr - 1];
containers[i->container].emplace_back(ArgIteratorInfo{argTok, i});
}
// Lambda is used to escape the nested loops
[&] {
for (const auto& p : containers)
{
const std::vector<ArgIteratorInfo>& cargs = p.second;
for (ArgIteratorInfo iter1 : cargs) {
for (ArgIteratorInfo iter2 : cargs) {
if (iter1.tok == iter2.tok)
continue;
if (iter1.info->first && iter2.info->last &&
isSameExpression(false, iter1.tok, iter2.tok, *mSettings, false, false))
sameIteratorExpressionError(iter1.tok);
if (checkIteratorPair(iter1.tok, iter2.tok))
return;
}
}
}
}();
}
}
for (const Variable *var : symbolDatabase->variableList()) {
if (var && var->isStlStringType() && Token::Match(var->nameToken(), "%var% (") &&
Token::Match(var->nameToken()->tokAt(2), "%name% . begin|cbegin|rbegin|crbegin ( ) , %name% . end|cend|rend|crend ( ) ,|)")) {
if (var->nameToken()->strAt(2) != var->nameToken()->strAt(8)) {
mismatchingContainersError(var->nameToken(), var->nameToken()->tokAt(2));
}
}
}
}
void CheckStl::mismatchingContainerIterator()
{
logChecker("CheckStl::misMatchingContainerIterator");
// Check if different containers are used in various calls of standard functions
const SymbolDatabase *symbolDatabase = mTokenizer->getSymbolDatabase();
for (const Scope * scope : symbolDatabase->functionScopes) {
for (const Token* tok = scope->bodyStart->next(); tok != scope->bodyEnd; tok = tok->next()) {
if (!astIsContainer(tok))
continue;
if (!astIsLHS(tok))
continue;
if (!Token::Match(tok->astParent(), ". %name% ( !!)"))
continue;
const Token* const ftok = tok->astParent()->next();
const std::vector<const Token *> args = getArguments(ftok);
const Library::Container * c = tok->valueType()->container;
const Library::Container::Action action = c->getAction(tok->strAt(2));
const Token* iterTok = nullptr;
if (action == Library::Container::Action::INSERT && args.size() == 2) {
// Skip if iterator pair
if (astIsIterator(args.back()))
continue;
if (!astIsIterator(args.front()))
continue;
iterTok = args.front();
} else if (action == Library::Container::Action::ERASE) {
if (!astIsIterator(args.front()))
continue;
iterTok = args.front();
} else {
continue;
}
ValueFlow::Value val = getLifetimeIteratorValue(iterTok);
if (!val.tokvalue)
continue;
if (!val.isKnown() && Token::simpleMatch(val.tokvalue->astParent(), ":"))
continue;
if (val.lifetimeKind != ValueFlow::Value::LifetimeKind::Iterator)
continue;
if (iterTok->str() == "*" && iterTok->astOperand1()->valueType() && iterTok->astOperand1()->valueType()->type == ValueType::ITERATOR)
continue;
if (isSameIteratorContainerExpression(tok, val.tokvalue, *mSettings))
continue;
mismatchingContainerIteratorError(tok, iterTok, val.tokvalue);
}
}
}
static const Token* getInvalidMethod(const Token* tok)
{
if (!astIsLHS(tok))
return nullptr;
if (Token::Match(tok->astParent(), ". assign|clear|swap"))
return tok->astParent()->next();
if (Token::Match(tok->astParent(), "%assign%"))
return tok->astParent();
const Token* ftok = nullptr;
if (Token::Match(tok->astParent(), ". %name% ("))
ftok = tok->astParent()->next();
if (!ftok)
return nullptr;
if (const Library::Container * c = tok->valueType()->container) {
const Library::Container::Action action = c->getAction(ftok->str());
if (c->unstableErase) {
if (action == Library::Container::Action::ERASE)
return ftok;
}
if (c->unstableInsert) {
if (action == Library::Container::Action::RESIZE)
return ftok;
if (action == Library::Container::Action::CLEAR)
return ftok;
if (action == Library::Container::Action::PUSH)
return ftok;
if (action == Library::Container::Action::POP)
return ftok;
if (action == Library::Container::Action::INSERT)
return ftok;
if (action == Library::Container::Action::CHANGE)
return ftok;
if (action == Library::Container::Action::CHANGE_INTERNAL)
return ftok;
if (Token::Match(ftok, "insert|emplace"))
return ftok;
}
}
return nullptr;
}
namespace {
struct InvalidContainerAnalyzer {
struct Info {
struct Reference {
const Token* tok;
ErrorPath errorPath;
const Token* ftok;
};
std::unordered_map<int, Reference> expressions;
void add(const std::vector<Reference>& refs) {
for (const Reference& r : refs) {
add(r);
}
}
void add(const Reference& r) {
if (!r.tok)
return;
expressions.emplace(r.tok->exprId(), r);
}
std::vector<Reference> invalidTokens() const {
std::vector<Reference> result;
std::transform(expressions.cbegin(), expressions.cend(), std::back_inserter(result), SelectMapValues{});
return result;
}
};