https://gcc.gnu.org/bugzilla/show_bug.cgi?id=102095
Bug ID: 102095
Summary: Returned reference to temporary not caught by
-fsanitize=undefined
Product: gcc
Version: 11.1.1
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: sanitizer
Assignee: unassigned at gcc dot gnu.org
Reporter: loximann at gmail dot com
CC: dodji at gcc dot gnu.org, dvyukov at gcc dot gnu.org,
jakub at gcc dot gnu.org, kcc at gcc dot gnu.org, marxin at
gcc dot gnu.org
Target Milestone: ---
The following code results in undefined behaviour (I believe), but it is not
caught by -fsanitize=undefined:
#include <functional>
#include <iostream>
#include <tuple>
template <typename T>
std::function<const T&()> constant(const T& c) {
return [c]() noexcept -> const T&{ return c; };
}
template <typename T>
std::function<std::tuple<T>()> zip_good(const std::function<T()>& f) {
return [f]() { return std::tuple<T>{f()}; };
}
template <typename T>
std::function<std::tuple<T>()> zip_bad(const std::function<T()>& f) {
return [f]() { return std::tuple{f()}; }; // <- UNDEFINED if T is const ref
}
int main() {
std::cout << std::get<0>(zip_good(constant(1.0))()) << std::endl;
std::cout << std::get<0>(zip_bad(constant(1.0))()) << std::endl;
}
