[Bug c++/112350] New: gcc is not triggering a dangling reference indicating stack use after return

[mohamed.selim at dxc dot com via Gcc-bugs]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=112350

            Bug ID: 112350
           Summary: gcc is not triggering a dangling reference indicating
                    stack use after return
           Product: gcc
           Version: 13.2.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: c++
          Assignee: unassigned at gcc dot gnu.org
          Reporter: mohamed.selim at dxc dot com
  Target Milestone: ---

Scenario A:
gcc is not triggering a dangling reference indicating stack use after return,
the address-sanitizer does trigger though.

"==1==ERROR: AddressSanitizer: stack-use-after-return on"

Scenario B:
gcc triggers a warning "-Wreturn-local-addr"

The sanitizers intervenes in both scenarios as expected, while gcc warnings in
not triggered in scenario A. Looks like the reference_wrapper has something to
do with it.


compiler options used:
-std=c++14 -Wframe-address -Wreturn-local-addr -Wall -Wextra -Wpedantic
-fsanitize=address


#include <iostream>
#include <utility>


// scenario A
const int& foo()
{
    int x = 234;
    std::reference_wrapper<int> s{x};

    return s.get();
}

// scenario B
const int& foo()
{
    int s = 234;   
    return s;
}

int main()
{
    const auto& f_res = foo();
    std::cout << "result: " << f_res << "\n";

    return 0;
}