Stash std::strings used for tp_name in internals

Types need `tp_name` set to a C-style string, but the current `strdup`
ends up with a leak (issue #977).  This avoids the strdup by storing
the `std::string` in internals so that during interpreter shutdown it
will be properly destroyed.
This commit is contained in:
Jason Rhinelander 2017-08-04 10:42:39 -04:00
parent 7437c69500
commit 2640c950ca
2 changed files with 15 additions and 5 deletions

View File

@ -518,12 +518,11 @@ inline PyObject* make_new_python_type(const type_record &rec) {
module = rec.scope.attr("__name__");
}
auto full_name = c_str(
#if !defined(PYPY_VERSION)
const auto full_name = module ? str(module).cast<std::string>() + "." + rec.name
: std::string(rec.name);
#else
const auto full_name = std::string(rec.name);
module ? str(module).cast<std::string>() + "." + rec.name :
#endif
rec.name);
char *tp_doc = nullptr;
if (rec.doc && options::show_user_defined_docstrings()) {
@ -556,7 +555,7 @@ inline PyObject* make_new_python_type(const type_record &rec) {
#endif
auto type = &heap_type->ht_type;
type->tp_name = strdup(full_name.c_str());
type->tp_name = full_name;
type->tp_doc = tp_doc;
type->tp_base = type_incref((PyTypeObject *)base);
type->tp_basicsize = static_cast<ssize_t>(sizeof(instance));

View File

@ -494,6 +494,7 @@ struct internals {
std::forward_list<void (*) (std::exception_ptr)> registered_exception_translators;
std::unordered_map<std::string, void *> shared_data; // Custom data to be shared across extensions
std::vector<PyObject *> loader_patient_stack; // Used by `loader_life_support`
std::forward_list<std::string> static_strings; // Stores the std::strings backing detail::c_str()
PyTypeObject *static_property_type;
PyTypeObject *default_metaclass;
PyObject *instance_base;
@ -688,6 +689,16 @@ using expand_side_effects = bool[];
#define PYBIND11_EXPAND_SIDE_EFFECTS(PATTERN) pybind11::detail::expand_side_effects{ ((PATTERN), void(), false)..., false }
#endif
/// Constructs a std::string with the given arguments, stores it in `internals`, and returns its
/// `c_str()`. Such strings objects have a long storage duration -- the internal strings are only
/// cleared when the program exits or after interpreter shutdown (when embedding), and so are
/// suitable for c-style strings needed by Python internals (such as PyTypeObject's tp_name).
template <typename... Args> const char *c_str(Args &&...args) {
auto &strings = get_internals().static_strings;
strings.emplace_front(std::forward<Args>(args)...);
return strings.front().c_str();
}
NAMESPACE_END(detail)
/// Returns a named pointer that is shared among all extension modules (using the same