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New check: Use make_shared/make_unique (#5673)

This commit is contained in:
Zachary Blair 2015-01-04 11:07:53 +01:00 committed by PKEuS
parent 016e89e422
commit 22bd20c94a
3 changed files with 121 additions and 0 deletions
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58
lib/checkmemoryleak.cpp
View File

@ -2692,6 +2692,10 @@ void CheckMemoryLeakNoVar::check()
// Checks if a call to an allocation function like malloc() is made and its return value is not assigned.
checkForUnusedReturnValue(scope);
// Checks to see if a function is called with memory allocated for an argument that
// could be leaked if a function called for another argument throws.
checkForUnsafeArgAlloc(scope);
// goto the "}" that ends the executable scope..
const Token *tok = scope->classEnd;
@ -2748,6 +2752,52 @@ void CheckMemoryLeakNoVar::checkForUnusedReturnValue(const Scope *scope)
}
}
//---------------------------------------------------------------------------
// Check if an exception could cause a leak in an argument constructed with
// shared_ptr/unique_ptr. For example, in the following code, it is possible
// that if g() throws an exception, the memory allocated by "new int(42)"
// could be leaked. See stackoverflow.com/questions/19034538/
// why-is-there-memory-leak-while-using-shared-ptr-as-a-function-parameter
//
// void x() {
// f(shared_ptr<int>(new int(42)), g());
// }
//---------------------------------------------------------------------------
void CheckMemoryLeakNoVar::checkForUnsafeArgAlloc(const Scope *scope)
{
// This test only applies to C++ source
if (!_tokenizer->isCPP() || !_settings->inconclusive || !_settings->isEnabled("warning"))
return;
for (const Token *tok = scope->classStart; tok != scope->classEnd; tok = tok->next()) {
if (Token::Match(tok, "%var% (")) {
const Token *endParamToken = tok->next()->link();
std::string pointerType;
std::string objectType;
std::string functionCalled;
// Scan through the arguments to the function call
for (const Token *tok2 = tok->tokAt(2); tok2 && tok2 != endParamToken; tok2 = tok2->nextArgument()) {
const Function *pFunc = tok2->function();
const bool isNothrow = pFunc && (pFunc->isDeclspecNothrow() || pFunc->isAttributeNothrow());
if (Token::Match(tok2, "shared_ptr|unique_ptr < %var% > ( new %var%")) {
pointerType = tok2->str();
objectType = tok2->strAt(6);
} else if (!isNothrow) {
if (Token::Match(tok2, "%var% ("))
functionCalled = tok2->str();
else if (Token::Match(tok2, "%var% < %var% > ("))
functionCalled = tok2->str() + "<" + tok2->strAt(2) + ">";
}
}
if (!pointerType.empty() && !functionCalled.empty())
unsafeArgAllocError(tok, functionCalled, pointerType, objectType);
}
}
}
void CheckMemoryLeakNoVar::functionCallLeak(const Token *loc, const std::string &alloc, const std::string &functionCall)
{
reportError(loc, Severity::error, "leakNoVarFunctionCall", "Allocation with " + alloc + ", " + functionCall + " doesn't release it.");
@ -2757,3 +2807,11 @@ void CheckMemoryLeakNoVar::returnValueNotUsedError(const Token *tok, const std::
{
reportError(tok, Severity::error, "leakReturnValNotUsed", "Return value of allocation function " + alloc + " is not used.");
}
void CheckMemoryLeakNoVar::unsafeArgAllocError(const Token *tok, const std::string &funcName, const std::string &ptrType, const std::string& objType)
{
const std::string factoryFunc = ptrType == "shared_ptr" ? "make_shared" : "make_unique";
reportError(tok, Severity::warning, "leakUnsafeArgAlloc",
"Unsafe allocation. If " + funcName + "() throws, memory could be leaked. Use " + factoryFunc + "<" + objType + ">() instead.",
true); // Inconclusive because funcName may never throw
}

8
lib/checkmemoryleak.h
View File

@ -446,14 +446,22 @@ private:
*/
void checkForUnusedReturnValue(const Scope *scope);
/**
* @brief %Check if an exception could cause a leak in an argument constructed with shared_ptr/unique_ptr.
* @param scope The scope of the function to check.
*/
void checkForUnsafeArgAlloc(const Scope *scope);
void functionCallLeak(const Token *loc, const std::string &alloc, const std::string &functionCall);
void returnValueNotUsedError(const Token* tok, const std::string &alloc);
void unsafeArgAllocError(const Token *tok, const std::string &funcName, const std::string &ptrType, const std::string &objType);
void getErrorMessages(ErrorLogger *e, const Settings *settings) const {
CheckMemoryLeakNoVar c(0, settings, e);
c.functionCallLeak(0, "funcName", "funcName");
c.returnValueNotUsedError(0, "funcName");
c.unsafeArgAllocError(0, "funcName", "shared_ptr", "int");
}
static std::string myName() {

55
test/testmemleak.cpp
View File

@ -6277,6 +6277,8 @@ private:
void run() {
settings.standards.posix = true;
settings.inconclusive = true;
settings.addEnabled("warning");
LOAD_LIB_2(settings.library, "gtk.cfg");
@ -6293,8 +6295,12 @@ private:
// pass allocated memory to function..
TEST_CASE(functionParameter);
// never use leakable resource
TEST_CASE(missingAssignment);
// pass allocated memory to function using a smart pointer
TEST_CASE(smartPointerFunctionParam);
}
void functionParameter() {
@ -6441,6 +6447,55 @@ private:
"}");
TODO_ASSERT_EQUALS("[test.cpp:7]: (error) Return value of allocation function f is not used.\n", "", errout.str());
}
void smartPointerFunctionParam() {
check("void x() {\n"
" f(shared_ptr<int>(new int(42)), g());\n"
"}");
ASSERT_EQUALS("[test.cpp:2]: (warning, inconclusive) Unsafe allocation. If g() throws, memory could be leaked. Use make_shared<int>() instead.\n", errout.str());
check("void x() {\n"
" h(12, f(shared_ptr<int>(new int(42)), g()));\n"
"}");
ASSERT_EQUALS("[test.cpp:2]: (warning, inconclusive) Unsafe allocation. If g() throws, memory could be leaked. Use make_shared<int>() instead.\n", errout.str());
check("void x() {\n"
" f(unique_ptr<int>(new int(42)), g());\n"
"}");
ASSERT_EQUALS("[test.cpp:2]: (warning, inconclusive) Unsafe allocation. If g() throws, memory could be leaked. Use make_unique<int>() instead.\n", errout.str());
check("void x() {\n"
" f(g(), shared_ptr<int>(new int(42)));\n"
"}");
ASSERT_EQUALS("[test.cpp:2]: (warning, inconclusive) Unsafe allocation. If g() throws, memory could be leaked. Use make_shared<int>() instead.\n", errout.str());
check("void x() {\n"
" f(g(), unique_ptr<int>(new int(42)));\n"
"}");
ASSERT_EQUALS("[test.cpp:2]: (warning, inconclusive) Unsafe allocation. If g() throws, memory could be leaked. Use make_unique<int>() instead.\n", errout.str());
check("void x() {\n"
" f(shared_ptr<char>(new char), make_unique<int>(32));\n"
"}");
ASSERT_EQUALS("[test.cpp:2]: (warning, inconclusive) Unsafe allocation. If make_unique<int>() throws, memory could be leaked. Use make_shared<char>() instead.\n", errout.str());
check("void x() {\n"
" f(g(124), h(\"test\", 234), shared_ptr<char>(new char));\n"
"}");
ASSERT_EQUALS("[test.cpp:2]: (warning, inconclusive) Unsafe allocation. If h() throws, memory could be leaked. Use make_shared<char>() instead.\n", errout.str());
check("void g(int x) throw() { }\n"
"void x() {\n"
" f(g(124), shared_ptr<char>(new char));\n"
"}");
ASSERT_EQUALS("", errout.str());
check("void __declspec(nothrow) g(int x) { }\n"
"void x() {\n"
" f(g(124), shared_ptr<char>(new char));\n"
"}");
ASSERT_EQUALS("", errout.str());
}
};
REGISTER_TEST(TestMemleakNoVar)