Index: cfe/trunk/docs/analyzer/checkers.rst =================================================================== --- cfe/trunk/docs/analyzer/checkers.rst +++ cfe/trunk/docs/analyzer/checkers.rst @@ -242,10 +242,35 @@ .. _cplusplus-InnerPointer: -cplusplus.InnerPointer -"""""""""""""""""""""" +cplusplus.InnerPointer (C++) +"""""""""""""""""""""""""""" Check for inner pointers of C++ containers used after re/deallocation. +Many container methods in the C++ standard library are known to invalidate +"references" (including actual references, iterators and raw pointers) to +elements of the container. Using such references after they are invalidated +causes undefined behavior, which is a common source of memory errors in C++ that +this checker is capable of finding. + +The checker is currently limited to ``std::string`` objects and doesn't +recognize some of the more sophisticated approaches to passing unowned pointers +around, such as ``std::string_view``. + +.. code-block:: cpp + + void deref_after_assignment() { + std::string s = "llvm"; + const char *c = s.data(); // note: pointer to inner buffer of 'std::string' obtained here + s = "clang"; // note: inner buffer of 'std::string' reallocated by call to 'operator=' + consume(c); // warn: inner pointer of container used after re/deallocation + } + + const char *return_temp(int x) { + return std::to_string(x).c_str(); // warn: inner pointer of container used after re/deallocation + // note: pointer to inner buffer of 'std::string' obtained here + // note: inner buffer of 'std::string' deallocated by call to destructor + } + .. _cplusplus-NewDelete: cplusplus.NewDelete (C++)