4 ms·

You can add [[clang::lifetimebound]] on the suffix parameter and you get <source>:21:35: warning: temporary whose address is used as value of local variable

• pfultz2 4y ago
  You dont need annotations, cppcheck already warns with: test.cpp:16:45: error: Using object that is a temporary. [danglingTemporaryLifetime] assert((std::vector<int>{1, 2, 3, 4} == append34({1, 2}))); // FAIL: UB ^ test.cpp:3:12: note: Return lambda. return [&](std::vector<int>&& items) { ^ test.cpp:2:50: note: Passed to reference. auto make_appender(std::vector<int> const& suffix) { ^ test.cpp:4:36: note: Lambda captures variable by reference here. return append(move(items), suffix); ^ test.cpp:15:35: note: Passed to 'make_appender'. auto append34 = make_appender({3, 4}); ^ test.cpp:15:35: note: Temporary created here. auto append34 = make_appender({3, 4}); ^ test.cpp:16:45: note: Using object that is a temporary. assert((std::vector<int>{1, 2, 3, 4} == append34({1, 2}))); // FAIL: UB
  • dataflow 4y ago
    As awesome as that is, cppcheck doesn't seem ready for real-world use. Literally the first invocation I ran resulted in this error: error: Syntax Error: AST broken, binary operator '!=' doesn't have two operands. [internalAstError] explicit operator bool() const { return this->get() != pointer(); } This is for a simple wrapper class that looks like this: template<class T> class Foo : private Bar<T> { public: typedef value_type *pointer; pointer get() const { return ...; } explicit operator bool() const { return this->get() != pointer(); } }; Another example: void foo(uintptr_t const (&input)[2]) { if constexpr (sizeof(uintptr_t) == sizeof(int) && sizeof(long long) == 2 * sizeof(int)) { long long value; memcpy(&reinterpret_cast<uintptr_t *>(&value)[0], &input[0], sizeof(input[0])); memcpy(&reinterpret_cast<uintptr_t *>(&value)[1], &input[1], sizeof(input[1])); } } error: The address of local variable 'value' is accessed at non-zero index. [objectIndex] memcpy(&reinterpret_cast<uintptr_t *>(&value)[1], &input[1], sizeof(input[1])); ^