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#6572 False positive eraseDereference - in iterator class - flag error inconclusive if iterator is not STL type

This commit is contained in:
amai2012 2018-01-10 09:37:21 +01:00
parent d76c5c525c
commit b17807c568
3 changed files with 81 additions and 47 deletions
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30
lib/checkstl.cpp
View File

@ -61,7 +61,7 @@ void CheckStl::iteratorsError(const Token *tok, const std::string &container1, c
}
// Error message used when dereferencing an iterator that has been erased..
void CheckStl::dereferenceErasedError(const Token *erased, const Token* deref, const std::string &itername)
void CheckStl::dereferenceErasedError(const Token *erased, const Token* deref, const std::string &itername, bool inconclusive)
{
if (erased) {
std::list<const Token*> callstack;
@ -70,12 +70,12 @@ void CheckStl::dereferenceErasedError(const Token *erased, const Token* deref, c
reportError(callstack, Severity::error, "eraseDereference",
"Iterator '" + itername + "' used after element has been erased.\n"
"The iterator '" + itername + "' is invalid after the element it pointed to has been erased. "
"Dereferencing or comparing it with another iterator is invalid operation.", CWE664, false);
"Dereferencing or comparing it with another iterator is invalid operation.", CWE664, inconclusive);
} else {
reportError(deref, Severity::error, "eraseDereference",
"Invalid iterator '" + itername + "' used.\n"
"The iterator '" + itername + "' is invalid before being assigned. "
"Dereferencing or comparing it with another iterator is invalid operation.", CWE664, false);
"Dereferencing or comparing it with another iterator is invalid operation.", CWE664, inconclusive);
}
}
@ -86,7 +86,7 @@ static const Token *skipMembers(const Token *tok)
return tok;
}
static bool isIterator(const Variable *var)
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"))
@ -99,8 +99,11 @@ static bool isIterator(const Variable *var)
// 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)
if (!end || end->argCount() > 0 || !incOperator) {
return false;
} else {
inconclusiveType = true; // heuristics only
}
}
return true;
@ -126,7 +129,8 @@ void CheckStl::iterators()
for (unsigned int iteratorId = 1; iteratorId < symbolDatabase->getVariableListSize(); iteratorId++) {
const Variable* var = symbolDatabase->getVariableFromVarId(iteratorId);
if (!isIterator(var))
bool inconclusiveType=false;
if (!isIterator(var, inconclusiveType))
continue;
// the validIterator flag says if the iterator has a valid value or not
@ -202,7 +206,8 @@ void CheckStl::iterators()
while (par2->str() != ")") {
if (par2->varId() == containerToken->varId())
break;
if (isIterator(par2->variable()))
bool inconclusiveType2=false;
if (isIterator(par2->variable(), inconclusiveType2))
break; // TODO: check if iterator points at same container
if (par2->str() == "(")
par2 = par2->link();
@ -266,10 +271,10 @@ void CheckStl::iterators()
// Dereferencing invalid iterator?
else if (!validIterator && Token::Match(tok2, "* %varid%", iteratorId)) {
dereferenceErasedError(eraseToken, tok2, tok2->strAt(1));
dereferenceErasedError(eraseToken, tok2, tok2->strAt(1), inconclusiveType);
tok2 = tok2->next();
} else if (!validIterator && Token::Match(tok2, "%varid% . %name%", iteratorId)) {
dereferenceErasedError(eraseToken, tok2, tok2->str());
dereferenceErasedError(eraseToken, tok2, tok2->str(), inconclusiveType);
tok2 = tok2->tokAt(2);
}
@ -514,7 +519,8 @@ void CheckStl::erase()
void CheckStl::eraseCheckLoopVar(const Scope &scope, const Variable *var)
{
if (!var || !Token::simpleMatch(var->typeEndToken(), "iterator"))
bool inconclusiveType=false;
if (!isIterator(var, inconclusiveType))
return;
for (const Token *tok = scope.classStart; tok != scope.classEnd; tok = tok->next()) {
if (tok->str() != "(")
@ -541,14 +547,14 @@ void CheckStl::eraseCheckLoopVar(const Scope &scope, const Variable *var)
if (tok2->varId() == var->declarationId()) {
if (Token::simpleMatch(tok2->next(), "="))
break;
dereferenceErasedError(tok, tok2, tok2->str());
dereferenceErasedError(tok, tok2, tok2->str(), inconclusiveType);
break;
}
if (indentlevel == 0U && Token::Match(tok2, "break|return|goto"))
break;
}
if (tok2 == scope.classEnd)
dereferenceErasedError(tok, scope.classDef, var->nameToken()->str());
dereferenceErasedError(tok, scope.classDef, var->nameToken()->str(), inconclusiveType);
}
}

8
lib/checkstl.h
View File

@ -55,8 +55,9 @@ public:
/** Simplified checks. The token list is simplified. */
void runSimplifiedChecks(const Tokenizer* tokenizer, const Settings* settings, ErrorLogger* errorLogger) {
if (!tokenizer->isCPP())
if (!tokenizer->isCPP()) {
return;
}
CheckStl checkStl(tokenizer, settings, errorLogger);
@ -161,8 +162,9 @@ public:
* @param erased token where the erase occurs
* @param deref token where the dereference occurs
* @param itername iterator name
* @param inconclusive inconclusive flag
*/
void dereferenceErasedError(const Token* erased, const Token* deref, const std::string &itername);
void dereferenceErasedError(const Token* erased, const Token* deref, const std::string& itername, bool inconclusive);
/** @brief Reading from empty stl container */
void readingEmptyStlContainer();
@ -208,7 +210,7 @@ private:
c.invalidIteratorError(nullptr, "iterator");
c.iteratorsError(nullptr, "container1", "container2");
c.mismatchingContainersError(nullptr);
c.dereferenceErasedError(nullptr, nullptr, "iter");
c.dereferenceErasedError(nullptr, nullptr, "iter", false);
c.stlOutOfBoundsError(nullptr, "i", "foo", false);
c.negativeIndexError(nullptr, ValueFlow::Value(-1));
c.invalidIteratorError(nullptr, "push_back|push_front|insert", "iterator");

28
test/teststl.cpp
View File

@ -137,6 +137,7 @@ private:
TEST_CASE(stabilityOfChecks); // #4684 cppcheck crash in template function call
TEST_CASE(dereferenceInvalidIterator);
TEST_CASE(dereferenceInvalidIterator2); // #6572
TEST_CASE(dereference_auto);
TEST_CASE(readingEmptyStlContainer);
@ -1600,7 +1601,7 @@ private:
" iterator i;\n"
" return i.foo();;\n"
"}");
ASSERT_EQUALS("[test.cpp:8]: (error) Invalid iterator 'i' used.\n", errout.str());
ASSERT_EQUALS("[test.cpp:8]: (error, inconclusive) Invalid iterator 'i' used.\n", errout.str());
}
void stlBoundaries6() { // #7106
@ -2896,6 +2897,31 @@ private:
ASSERT_EQUALS("", errout.str());
}
void dereferenceInvalidIterator2() {
// Self-implemented iterator class
check("class iterator {\n"
"public:\n"
" CCommitPointer m_ptr;\n"
" iterator() {}\n"
" CCommitPointer& operator*() {\n"
" return m_ptr;\n"
" }\n"
" CCommitPointer* operator->() {\n"
" return &m_ptr;\n"
" }\n"
" iterator& operator++() {\n"
" ++m_ptr.m_place;\n"
" return *this;\n"
" }\n"
" }; \n"
" iterator begin() {\n"
" iterator it; \n"
" it->m_place = 0;\n"
" return it; \n"
"}\n");
ASSERT_EQUALS("[test.cpp:18]: (error, inconclusive) Invalid iterator 'it' used.\n", errout.str());
}
void readingEmptyStlContainer() {
check("void f() {\n"
" std::map<int, std::string> CMap;\n"