[clang] Missing diagnostic when return a local vector as a span

[usx95]

https://godbolt.org/z/zes3e9jfr

This is a new false negative

#include<string>
#include <vector>

template <typename T>
struct [[gsl::Owner]] StatusOr {
  const T &value() [[clang::lifetimebound]];
};

template<typename T>
struct [[gsl::Pointer]] Span {
    Span(const std::vector<T> &V): V(V){}
    const std::vector<T> &V;
};

// Pointer<Owner<Pointer>>> from Owner<Pointer>
Span<int*> test9(std::vector<int*> V) {
  return V; // No diagnsotic
}

cc @hokein

[llvmbot]

@llvm/issue-subscribers-clang-frontend

Author: Utkarsh Saxena (usx95)

https://godbolt.org/z/zes3e9jfr

This is a new false negative

#include<string>
#include <vector>

template <typename T>
struct [[gsl::Owner]] StatusOr {
  const T &value() [[clang::lifetimebound]];
};

template<typename T>
struct [[gsl::Pointer]] Span {
    Span(const std::vector<T> &V): V(V){}
    const std::vector<T> &V;
};

// Pointer<Owner<Pointer>>> from Owner<Pointer>
Span<int*> test9(std::vector<int*> V) {
  return V; // FIXME.
}

cc @hokein

[hokein]

This issue was caused by the Container<GSLPointer> patch. The patch was reverted yesterday, but it seems the version of Clang used by Compiler Explorer is slightly behind. I’ve confirmed that the issue no longer exists after the revert. (will address this in the reland version).

[usx95]

I don't think so. Compiler explorer is only 10hr behind atm at 6d859c1. Revert of concerned commit was more than 24hr ago
I still see https://godbolt.org/z/MzW3Yaxb8 new false-negative.

[hokein]

I didn't reproduce it with my local build, and it doesn't seem to trigger on Clang (assertion trunk),
https://godbolt.org/z/dxW6KrjTP (this is weird).

[hokein]

https://godbolt.org/z/j49xx9GEP shows the clang trunk works as expected. (For your above link https://godbolt.org/z/zes3e9jfr, changing the source file will make it work again, we probably need to refresh the cache of Compiler explorer).

[usx95]

Aah I see. Thanks for clarifying.
Then we can close this and make this work in #108344